| public CanConvertTo ( ITypeDescriptorContext context, Type destinationType ) : bool | ||
| context | ITypeDescriptorContext | |
| destinationType | Type | |
| 리턴 | bool | |
public void CheckConvert(int expect_from, int expect_to, TypeConverter conv, Type type) {
int from_count = 0;
int to_count = 0;
foreach (Type t in typeof(int).Assembly.GetTypes ()) {
if (conv.CanConvertFrom(null, t)) {
from_count++;
if (debug > 0) {
Console.WriteLine("{0}: Conversion from {1} supported", conv.ToString(), t.ToString());
}
}
if (conv.CanConvertTo(null, t)) {
to_count++;
if (debug > 0) {
Console.WriteLine("{0}: Conversion to {1} supported", conv.ToString(), t.ToString());
}
}
}
#if not
foreach (Type t in type.Assembly.GetTypes ()) {
if (conv.CanConvertFrom(null, t)) {
from_count++;
if (debug > 0) {
Console.WriteLine("{0}: Conversion from {1} supported", conv.ToString(), t.ToString());
}
}
if (conv.CanConvertTo(null, t)) {
to_count++;
if (debug > 0) {
Console.WriteLine("{0}: Conversion to {1} supported", conv.ToString(), t.ToString());
}
}
}
#endif
if (from_count != expect_from) {
if (verbose > 0) {
Console.WriteLine("{0}: ConvertFrom expected {1}, returned {2}", conv.ToString(), expect_from, from_count);
}
failed++;
}
if (to_count != expect_to) {
if (verbose > 0) {
Console.WriteLine("{0}: ConvertTo expected {1}, returned {2}", conv.ToString(), expect_to, to_count);
}
failed++;
}
}
private static object DoConversion(object value, Type toType, CultureInfo culture)
{
if ((value is IConvertible) || (value == null))
{
try
{
return(System.Convert.ChangeType(value, toType, culture));
}
catch (Exception)
{
return(DependencyProperty.UnsetValue);
}
}
else
{
System.ComponentModel.TypeConverter typeConverter = TypeDescriptor.GetConverter(value);
if (typeConverter.CanConvertTo(toType))
{
return(typeConverter.ConvertTo(null, culture, value, toType));
}
}
return(DependencyProperty.UnsetValue);
}
/// <summary>
/// 转换简单类型
/// </summary>
/// <param name="value"></param>
/// <param name="type"></param>
/// <returns></returns>
private static object ConvertObj(object value, Type type)
{
object returnValue;
if ((value == null) || type.IsInstanceOfType(value))
{
return(value);
}
string str = value as string;
if ((str != null) && (str.Length == 0))
{
return(null);
}
System.ComponentModel.TypeConverter converter = TypeDescriptor.GetConverter(type);
bool flag = converter.CanConvertFrom(value.GetType());
if (!flag)
{
converter = TypeDescriptor.GetConverter(value.GetType());
}
if (!flag && !converter.CanConvertTo(type))
{
throw new InvalidOperationException("无法转换成类型：" + value.ToString() + "==>" + type);
}
try
{
returnValue = flag ? converter.ConvertFrom(null, null, value) : converter.ConvertTo(null, null, value, type);
}
catch (Exception e)
{
throw new InvalidOperationException("类型转换出错：" + value.ToString() + "==>" + type, e);
}
return(returnValue);
}
protected internal ModelValueProperty(ModelType declaringType, string name, string label, string helptext, string format, bool isStatic, Type propertyType, TypeConverter converter, bool isList = false, bool isReadOnly = false, bool isPersisted = true, Attribute[] attributes = null, LambdaExpression defaultValue = null)
: base(declaringType, name, label, helptext, format, isStatic, isList, isReadOnly, isPersisted, attributes)
{
this.PropertyType = propertyType;
this.Converter = converter;
this.AutoConvert = converter != null && converter.CanConvertTo(typeof(object));
this.FormatProvider = declaringType.GetFormatProvider(propertyType);
if (defaultValue != null)
{
if (defaultValue.Parameters.Count > 0)
throw new ArgumentException("Default value expressions cannot have parameters.");
if (propertyType.IsAssignableFrom(defaultValue.Type))
throw new ArgumentException("Default value expressions must match the type of the property they are for.");
this.DefaultValue = defaultValue;
}
}
private static object ConvertSimpleType(CultureInfo culture, object value, Type destinationType)
{
if (value == null || destinationType.IsInstanceOfType(value))
{
return(value);
}
// if this is a user-input value but the user didn't type anything, return no value
string valueAsString = value as string;
if (valueAsString != null && valueAsString.Trim().Length == 0)
{
return(null);
}
//modified by Yang Li
//TypeConverter converter = TypeDescriptor.GetConverter(destinationType);
System.ComponentModel.TypeConverter converter = TypeDescriptor.GetConverter(destinationType);
bool canConvertFrom = converter.CanConvertFrom(value.GetType());
if (!canConvertFrom)
{
converter = TypeDescriptor.GetConverter(value.GetType());
}
if (!(canConvertFrom || converter.CanConvertTo(destinationType)))
{
string message = String.Format(CultureInfo.CurrentCulture, MvcResources.ValueProviderResult_NoConverterExists,
value.GetType().FullName, destinationType.FullName);
throw new InvalidOperationException(message);
}
try
{
object convertedValue = (canConvertFrom) ?
converter.ConvertFrom(null /* context */, culture, value) :
converter.ConvertTo(null /* context */, culture, value, destinationType);
return(convertedValue);
}
catch (Exception ex)
{
string message = String.Format(CultureInfo.CurrentCulture, MvcResources.ValueProviderResult_ConversionThrew,
value.GetType().FullName, destinationType.FullName);
throw new InvalidOperationException(message, ex);
}
}
public virtual object ParseFormattedValue (object formattedValue, DataGridViewCellStyle cellStyle, TypeConverter formattedValueTypeConverter, TypeConverter valueTypeConverter)
{
if (cellStyle == null)
throw new ArgumentNullException ("cellStyle is null.");
if (FormattedValueType == null)
throw new FormatException ("The System.Windows.Forms.DataGridViewCell.FormattedValueType property value is null.");
if (formattedValue == null)
throw new ArgumentException ("formattedValue is null.");
if (ValueType == null)
throw new FormatException ("valuetype is null");
if (!FormattedValueType.IsAssignableFrom (formattedValue.GetType ()))
throw new ArgumentException ("formattedValue is not of formattedValueType.");
if (formattedValueTypeConverter == null)
formattedValueTypeConverter = FormattedValueTypeConverter;
if (valueTypeConverter == null)
valueTypeConverter = ValueTypeConverter;
if (valueTypeConverter != null && valueTypeConverter.CanConvertFrom (FormattedValueType))
return valueTypeConverter.ConvertFrom (formattedValue);
if (formattedValueTypeConverter != null && formattedValueTypeConverter.CanConvertTo (ValueType))
return formattedValueTypeConverter.ConvertTo (formattedValue, ValueType);
return Convert.ChangeType (formattedValue, ValueType);
}
public static bool Convert(object val, Type targetType, out object result)
{
result = val;
// Trivial cases
if (val == null)
{
// Cannot convert null to value type
return(!targetType.IsValueType);
}
if (targetType.IsAssignableFrom(val.GetType()))
{
return(true);
}
// Custom type conversions
if (_customTypeConverter != null)
{
if (_customTypeConverter(val, targetType, out result))
{
return(true);
}
}
// TODO: typeof(Nullable<T>)
// Built-in type conversions
if (val.GetType() == typeof(string) && targetType == typeof(Type))
{ // string -> Type
result = Type.GetType(val.ToString());
return(result != null);
}
// Enumerations
if (val.GetType() == typeof(string) && targetType.IsEnum)
{ // string -> Enum
result = Enum.Parse(targetType, (string)val);
return(true);
}
// String target type must be done before enumerations are tried - else, the string will be treated as enumeration
if (targetType.IsAssignableFrom(typeof(string)))
{ // * -> string
result = val.ToString();
return(true);
}
// Collection types
Type enumerableType;
Type entryType;
ReflectionHelper.FindImplementedEnumerableType(targetType, out enumerableType, out entryType);
if (enumerableType != null) // Targets IList, ICollection, IList<>, ICollection<>
{
ICollection col;
if (!ToCollection(val, entryType, out col))
{
return(false);
}
List <object> resultList = col.Cast <object>().ToList();
result = resultList;
return(true);
}
ICollection sourceCol = val as ICollection;
if (sourceCol != null && sourceCol.Count == 1) // From collection to non-collection target
{
// Use the first (single) item of a collection or dictionary
IEnumerator enumerator = sourceCol.GetEnumerator();
enumerator.MoveNext();
object item = enumerator.Current;
if (Convert(item, targetType, out result)) // Single collection item
{
return(true);
}
KeyValuePair <object, object>?kvp = item as KeyValuePair <object, object>?;
if (kvp.HasValue && Convert(kvp.Value.Value, targetType, out result)) // Value of single dictionary entry - generic dictionary
{
IDisposable d = kvp.Value.Key as IDisposable;
if (d != null)
{
d.Dispose();
}
return(true);
}
DictionaryEntry?entry = item as DictionaryEntry?;
if (entry.HasValue && Convert(entry.Value.Value, targetType, out result)) // Value of single dictionary entry - legacy dictionary
{
IDisposable d = entry.Value.Key as IDisposable;
if (d != null)
{
d.Dispose();
}
return(true);
}
}
// Simple type conversions
System.ComponentModel.TypeConverter tc = TypeDescriptor.GetConverter(targetType);
if (tc != null && tc.CanConvertFrom(val.GetType()))
{
try
{
result = tc.ConvertFrom(null, CultureInfo.InvariantCulture, val);
return(true);
}
catch { }
}
tc = TypeDescriptor.GetConverter(val);
if (tc != null && tc.CanConvertTo(targetType))
{
result = tc.ConvertTo(val, targetType);
return(true);
}
return(false);
}
/// <summary>
/// This method checks whether the specified object can be converted to string.
/// </summary>
/// <param name="rawValue">Value to check</param>
/// <param name="converter">Type converter object</param>
/// <returns>
/// True, if the type can be converted to string; otherwise, false;
/// </returns>
public static bool CanConvertToString(object rawValue, out TypeConverter converter)
{
var valueType = rawValue.GetType();
converter = TypeDescriptor.GetConverter(valueType);
return converter != null && converter.CanConvertTo(typeof(String));
}
/// <devdoc>
///
/// Converts a value into a format suitable for display to the end user.
///
/// - Converts DBNull or null into a suitable formatted representation of 'null'
/// - Performs some special-case conversions (eg. Boolean to CheckState)
/// - Uses TypeConverters or IConvertible where appropriate
/// - Throws a FormatException is no suitable conversion can be found
///
/// </devdoc>
private static object FormatObjectInternal(object value,
Type targetType,
TypeConverter sourceConverter,
TypeConverter targetConverter,
string formatString,
IFormatProvider formatInfo,
object formattedNullValue) {
if (value == System.DBNull.Value || value == null) {
//
// Convert DBNull to the formatted representation of 'null' (if possible)
//
if (formattedNullValue != null)
{
return formattedNullValue;
}
//
// Convert DBNull or null to a specific 'known' representation of null (otherwise fail)
//
if (targetType == stringType)
{
return String.Empty;
}
if (targetType == checkStateType) {
return CheckState.Indeterminate;
}
// Just pass null through: if this is a value type, it's been unwrapped here, so we return null
// and the caller has to wrap if appropriate.
return null;
}
//
// Special case conversions
//
if (targetType == stringType) {
if (value is IFormattable && !String.IsNullOrEmpty(formatString)) {
return (value as IFormattable).ToString(formatString, formatInfo);
}
}
//The converters for properties should take precedence. Unfortunately, we don't know whether we have one. Check vs. the
//type's TypeConverter. We're punting the case where the property-provided converter is the same as the type's converter.
Type sourceType = value.GetType();
TypeConverter sourceTypeTypeConverter = TypeDescriptor.GetConverter(sourceType);
if (sourceConverter != null && sourceConverter != sourceTypeTypeConverter && sourceConverter.CanConvertTo(targetType)) {
return sourceConverter.ConvertTo(null, GetFormatterCulture(formatInfo), value, targetType);
}
TypeConverter targetTypeTypeConverter = TypeDescriptor.GetConverter(targetType);
if (targetConverter != null && targetConverter != targetTypeTypeConverter && targetConverter.CanConvertFrom(sourceType)) {
return targetConverter.ConvertFrom(null, GetFormatterCulture(formatInfo), value);
}
if (targetType == checkStateType) {
if (sourceType == booleanType) {
return ((bool)value) ? CheckState.Checked : CheckState.Unchecked;
}
else {
if (sourceConverter == null) {
sourceConverter = sourceTypeTypeConverter;
}
if (sourceConverter != null && sourceConverter.CanConvertTo(booleanType)) {
return (bool)sourceConverter.ConvertTo(null, GetFormatterCulture(formatInfo), value, booleanType)
? CheckState.Checked : CheckState.Unchecked;
}
}
}
if (targetType.IsAssignableFrom(sourceType)) {
return value;
}
//
// If explicit type converters not provided, supply default ones instead
//
if (sourceConverter == null) {
sourceConverter = sourceTypeTypeConverter;
}
if (targetConverter == null) {
targetConverter = targetTypeTypeConverter;
}
//
// Standardized conversions
//
if (sourceConverter != null && sourceConverter.CanConvertTo(targetType)) {
return sourceConverter.ConvertTo(null, GetFormatterCulture(formatInfo), value, targetType);
}
else if (targetConverter != null && targetConverter.CanConvertFrom(sourceType)) {
return targetConverter.ConvertFrom(null, GetFormatterCulture(formatInfo), value);
}
else if (value is IConvertible) {
return ChangeType(value, targetType, formatInfo);
}
//
// Fail if no suitable conversion found
//
throw new FormatException(GetCantConvertMessage(value, targetType));
}
/// <devdoc>
///
/// Converts a value entered by the end user (through UI) into the corresponding binary value.
///
/// - Converts formatted representations of 'null' into DBNull
/// - Performs some special-case conversions (eg. CheckState to Boolean)
/// - Uses TypeConverters or IConvertible where appropriate
/// - Throws a FormatException is no suitable conversion can be found
///
/// </devdoc>
private static object ParseObjectInternal(object value,
Type targetType,
Type sourceType,
TypeConverter targetConverter,
TypeConverter sourceConverter,
IFormatProvider formatInfo,
object formattedNullValue) {
//
// Convert the formatted representation of 'null' to DBNull (if possible)
//
if (EqualsFormattedNullValue(value, formattedNullValue, formatInfo) || value == System.DBNull.Value) {
return System.DBNull.Value;
}
//
// Special case conversions
//
TypeConverter targetTypeTypeConverter = TypeDescriptor.GetConverter(targetType);
if (targetConverter != null && targetTypeTypeConverter != targetConverter && targetConverter.CanConvertFrom(sourceType)) {
return targetConverter.ConvertFrom(null, GetFormatterCulture(formatInfo), value);
}
TypeConverter sourceTypeTypeConverter = TypeDescriptor.GetConverter(sourceType);
if (sourceConverter != null && sourceTypeTypeConverter != sourceConverter && sourceConverter.CanConvertTo(targetType)) {
return sourceConverter.ConvertTo(null, GetFormatterCulture(formatInfo), value, targetType);
}
if (value is string) {
// If target type has a suitable Parse method, use that to parse strings
object parseResult = InvokeStringParseMethod(value, targetType, formatInfo);
if (parseResult != parseMethodNotFound) {
return parseResult;
}
}
else if (value is CheckState) {
CheckState state = (CheckState)value;
if (state == CheckState.Indeterminate) {
return DBNull.Value;
}
// Explicit conversion from CheckState to Boolean
if (targetType == booleanType) {
return (state == CheckState.Checked);
}
if (targetConverter == null) {
targetConverter = targetTypeTypeConverter;
}
if (targetConverter != null && targetConverter.CanConvertFrom(booleanType)) {
return targetConverter.ConvertFrom(null, GetFormatterCulture(formatInfo), state == CheckState.Checked);
}
}
else if (value != null && targetType.IsAssignableFrom(value.GetType())) {
// If value is already of a compatible type, just go ahead and use it
return value;
}
//
// If explicit type converters not provided, supply default ones instead
//
if (targetConverter == null) {
targetConverter = targetTypeTypeConverter;
}
if (sourceConverter == null) {
sourceConverter = sourceTypeTypeConverter;
}
//
// Standardized conversions
//
if (targetConverter != null && targetConverter.CanConvertFrom(sourceType)) {
return targetConverter.ConvertFrom(null, GetFormatterCulture(formatInfo), value);
}
else if (sourceConverter != null && sourceConverter.CanConvertTo(targetType)) {
return sourceConverter.ConvertTo(null, GetFormatterCulture(formatInfo), value, targetType);
}
else if (value is IConvertible) {
return ChangeType(value, targetType, formatInfo);
}
//
// Fail if no suitable conversion found
//
throw new FormatException(GetCantConvertMessage(value, targetType));
}
internal static bool CanConvertToFrom(TypeConverter converter, Type type) {
return (converter != null && converter.CanConvertTo(type) &&
converter.CanConvertFrom(type) && !(converter is ReferenceConverter));
}
bool SafeCanConvertTo (Type type, TypeConverter cvt)
{
try {
return cvt.CanConvertTo (type);
} catch (NotImplementedException) {
return false;
}
}
/// <inheritdoc />
public override bool TryConvert(object value, Type destinationType, out object result, ConversionArgs args)
{
System.ComponentModel.TypeConverter converter = TypeDescriptor.GetConverter(destinationType);
if (converter.GetType() != typeof(System.ComponentModel.TypeConverter) && converter.CanConvertFrom(value.GetType()))
{
try {
result = converter.ConvertFrom(null, args.Culture, value);
return(true);
}
catch {
}
}
converter = TypeDescriptor.GetConverter(value.GetType());
if (converter.GetType() != typeof(System.ComponentModel.TypeConverter) && converter.CanConvertTo(destinationType))
{
try {
result = converter.ConvertTo(null, args.Culture, value, destinationType);
return(true);
}
catch {
}
}
result = null;
return(false);
}
private static bool CanConvertToAndFromString(TypeConverter converter)
{
return converter.CanConvertFrom(typeof(string)) &&
converter.CanConvertTo(typeof(string));
}
protected virtual object GetFormattedValue (object value, int rowIndex, ref DataGridViewCellStyle cellStyle, TypeConverter valueTypeConverter, TypeConverter formattedValueTypeConverter, DataGridViewDataErrorContexts context)
{
if (DataGridView == null)
return null;
if (rowIndex < 0 || rowIndex >= DataGridView.RowCount)
throw new ArgumentOutOfRangeException ("rowIndex");
// Give the user a chance to custom format
if (!(this is DataGridViewRowHeaderCell)) {
DataGridViewCellFormattingEventArgs e = new DataGridViewCellFormattingEventArgs (ColumnIndex, rowIndex, value, FormattedValueType, cellStyle);
DataGridView.OnCellFormattingInternal (e);
if (e.FormattingApplied)
return e.Value;
cellStyle = e.CellStyle;
value = e.Value;
}
if (value == null || (cellStyle != null && value == cellStyle.DataSourceNullValue)) {
if (FormattedValueType == typeof (string))
return String.Empty;
}
if (FormattedValueType == typeof(string) && value is IFormattable && !String.IsNullOrEmpty (cellStyle.Format))
return ((IFormattable) value).ToString (cellStyle.Format, cellStyle.FormatProvider);
if (value != null && FormattedValueType.IsAssignableFrom (value.GetType()))
return value;
if (formattedValueTypeConverter == null)
formattedValueTypeConverter = FormattedValueTypeConverter;
if (valueTypeConverter == null)
valueTypeConverter = ValueTypeConverter;
if (valueTypeConverter != null && valueTypeConverter.CanConvertTo (FormattedValueType))
return valueTypeConverter.ConvertTo (value, FormattedValueType);
if (formattedValueTypeConverter != null && formattedValueTypeConverter.CanConvertFrom (ValueType))
return formattedValueTypeConverter.ConvertFrom (value);
return Convert.ChangeType (value, FormattedValueType);
}
public override bool CanConvertTo(cm.ITypeDescriptorContext context, Type destinationType)
{
return(etoConverter.CanConvertTo(destinationType));
}
public static object ChangeType(object value, Type destinationType, CultureInfo culture)
{
if (value == null || value.IsDbNull())
{
return((!destinationType.IsValueType()) ? null : Activator.CreateInstance(destinationType));
}
Type type = value.GetType();
if (destinationType == type || destinationType.IsAssignableFrom(type))
{
return(value);
}
if (destinationType.IsGenericType())
{
Type genericTypeDefinition = destinationType.GetGenericTypeDefinition();
if (genericTypeDefinition == typeof(Nullable <>))
{
Type destinationType2 = destinationType.GetGenericArguments()[0];
object obj = ChangeType(value, destinationType2, culture);
return(Activator.CreateInstance(destinationType, obj));
}
}
if (destinationType.IsEnum())
{
string text = value as string;
return((text == null) ? value : Enum.Parse(destinationType, text, true));
}
if (destinationType == typeof(bool))
{
if ("0".Equals(value))
{
return(false);
}
if ("1".Equals(value))
{
return(true);
}
}
System.ComponentModel.TypeConverter converter = TypeDescriptor.GetConverter(type);
if (converter != null && converter.CanConvertTo(destinationType))
{
return(converter.ConvertTo(null, culture, value, destinationType));
}
System.ComponentModel.TypeConverter converter2 = TypeDescriptor.GetConverter(destinationType);
if (converter2 != null && converter2.CanConvertFrom(type))
{
return(converter2.ConvertFrom(null, culture, value));
}
Type[] array = new Type[2]
{
type,
destinationType
};
foreach (Type type2 in array)
{
foreach (MethodInfo publicStaticMethod2 in type2.GetPublicStaticMethods())
{
if (publicStaticMethod2.IsSpecialName && (publicStaticMethod2.Name == "op_Implicit" || publicStaticMethod2.Name == "op_Explicit") && destinationType.IsAssignableFrom(publicStaticMethod2.ReturnParameter.ParameterType))
{
ParameterInfo[] parameters = publicStaticMethod2.GetParameters();
if (parameters.Length == 1 && parameters[0].ParameterType.IsAssignableFrom(type))
{
try
{
return(publicStaticMethod2.Invoke(null, new object[1]
{
value
}));
}
catch (TargetInvocationException ex)
{
throw ex.Unwrap();
}
}
}
}
}
if (type == typeof(string))
{
try
{
MethodInfo publicStaticMethod = destinationType.GetPublicStaticMethod("Parse", typeof(string), typeof(IFormatProvider));
if (publicStaticMethod != null)
{
return(publicStaticMethod.Invoke(null, new object[2]
{
value,
culture
}));
}
publicStaticMethod = ReflectionExtensions.GetPublicStaticMethod(destinationType, "Parse", typeof(string));
if (publicStaticMethod != null)
{
return(publicStaticMethod.Invoke(null, new object[1]
{
value
}));
}
}
catch (TargetInvocationException ex2)
{
throw ex2.Unwrap();
}
}
if (destinationType == typeof(TimeSpan))
{
return(TimeSpan.Parse((string)ChangeType(value, typeof(string), CultureInfo.InvariantCulture)));
}
return(Convert.ChangeType(value, destinationType, CultureInfo.InvariantCulture));
}
/// <summary>
/// Returns whether this converter can convert the object to the specified type, using the specified context.
/// </summary>
/// <param name="context">An <see cref="T:System.ComponentModel.ITypeDescriptorContext"></see> that provides a format context.</param>
/// <param name="destinationType">A <see cref="T:System.Type"></see> that represents the type you want to convert to.</param>
/// <returns>
/// true if this converter can perform the conversion; otherwise, <c>false</c>.
/// </returns>
public override bool CanConvertTo(System.ComponentModel.ITypeDescriptorContext context,
Type destinationType)
{
return(destinationType == typeof(string) || baseTypeConverter.CanConvertTo(context, destinationType));
}
private void CreateConverter() {
// Some properties cannot have type converters.
// Such examples are properties that are ConfigurationElement ( derived classes )
// or properties which are user-defined and the user code handles serialization/desirialization so
// the property itself is never converted to/from string
if (_converter == null) {
// Enums are exception. We use our custom converter for all enums
if (_type.IsEnum) {
_converter = new GenericEnumConverter(_type);
}
else if (!_type.IsSubclassOf(typeof(ConfigurationElement))) {
_converter = TypeDescriptor.GetConverter(_type);
if ((_converter == null) ||
!_converter.CanConvertFrom(typeof(String)) ||
!_converter.CanConvertTo(typeof(String))) {
throw new ConfigurationErrorsException(SR.GetString(SR.No_converter, _name, _type.Name));
}
}
}
}
private static object ParseObjectInternal(object value, System.Type targetType, System.Type sourceType, TypeConverter targetConverter, TypeConverter sourceConverter, IFormatProvider formatInfo, object formattedNullValue)
{
if (EqualsFormattedNullValue(value, formattedNullValue, formatInfo) || (value == DBNull.Value))
{
return DBNull.Value;
}
TypeConverter converter = TypeDescriptor.GetConverter(targetType);
if (((targetConverter != null) && (converter != targetConverter)) && targetConverter.CanConvertFrom(sourceType))
{
return targetConverter.ConvertFrom(null, GetFormatterCulture(formatInfo), value);
}
TypeConverter converter2 = TypeDescriptor.GetConverter(sourceType);
if (((sourceConverter != null) && (converter2 != sourceConverter)) && sourceConverter.CanConvertTo(targetType))
{
return sourceConverter.ConvertTo(null, GetFormatterCulture(formatInfo), value, targetType);
}
if (value is string)
{
object obj2 = InvokeStringParseMethod(value, targetType, formatInfo);
if (obj2 != parseMethodNotFound)
{
return obj2;
}
}
else if (value is CheckState)
{
CheckState state = (CheckState) value;
if (state == CheckState.Indeterminate)
{
return DBNull.Value;
}
if (targetType == booleanType)
{
return (state == CheckState.Checked);
}
if (targetConverter == null)
{
targetConverter = converter;
}
if ((targetConverter != null) && targetConverter.CanConvertFrom(booleanType))
{
return targetConverter.ConvertFrom(null, GetFormatterCulture(formatInfo), state == CheckState.Checked);
}
}
else if ((value != null) && targetType.IsAssignableFrom(value.GetType()))
{
return value;
}
if (targetConverter == null)
{
targetConverter = converter;
}
if (sourceConverter == null)
{
sourceConverter = converter2;
}
if ((targetConverter != null) && targetConverter.CanConvertFrom(sourceType))
{
return targetConverter.ConvertFrom(null, GetFormatterCulture(formatInfo), value);
}
if ((sourceConverter != null) && sourceConverter.CanConvertTo(targetType))
{
return sourceConverter.ConvertTo(null, GetFormatterCulture(formatInfo), value, targetType);
}
if (!(value is IConvertible))
{
throw new FormatException(GetCantConvertMessage(value, targetType));
}
return ChangeType(value, targetType, formatInfo);
}
private static object FormatObjectInternal(object value, System.Type targetType, TypeConverter sourceConverter, TypeConverter targetConverter, string formatString, IFormatProvider formatInfo, object formattedNullValue)
{
if ((value == DBNull.Value) || (value == null))
{
if (formattedNullValue != null)
{
return formattedNullValue;
}
if (targetType == stringType)
{
return string.Empty;
}
if (targetType == checkStateType)
{
return CheckState.Indeterminate;
}
return null;
}
if (((targetType == stringType) && (value is IFormattable)) && !string.IsNullOrEmpty(formatString))
{
return (value as IFormattable).ToString(formatString, formatInfo);
}
System.Type type = value.GetType();
TypeConverter converter = TypeDescriptor.GetConverter(type);
if (((sourceConverter != null) && (sourceConverter != converter)) && sourceConverter.CanConvertTo(targetType))
{
return sourceConverter.ConvertTo(null, GetFormatterCulture(formatInfo), value, targetType);
}
TypeConverter converter2 = TypeDescriptor.GetConverter(targetType);
if (((targetConverter != null) && (targetConverter != converter2)) && targetConverter.CanConvertFrom(type))
{
return targetConverter.ConvertFrom(null, GetFormatterCulture(formatInfo), value);
}
if (targetType == checkStateType)
{
if (type == booleanType)
{
return (((bool) value) ? CheckState.Checked : CheckState.Unchecked);
}
if (sourceConverter == null)
{
sourceConverter = converter;
}
if ((sourceConverter != null) && sourceConverter.CanConvertTo(booleanType))
{
return (((bool) sourceConverter.ConvertTo(null, GetFormatterCulture(formatInfo), value, booleanType)) ? CheckState.Checked : CheckState.Unchecked);
}
}
if (targetType.IsAssignableFrom(type))
{
return value;
}
if (sourceConverter == null)
{
sourceConverter = converter;
}
if (targetConverter == null)
{
targetConverter = converter2;
}
if ((sourceConverter != null) && sourceConverter.CanConvertTo(targetType))
{
return sourceConverter.ConvertTo(null, GetFormatterCulture(formatInfo), value, targetType);
}
if ((targetConverter != null) && targetConverter.CanConvertFrom(type))
{
return targetConverter.ConvertFrom(null, GetFormatterCulture(formatInfo), value);
}
if (!(value is IConvertible))
{
throw new FormatException(GetCantConvertMessage(value, targetType));
}
return ChangeType(value, targetType, formatInfo);
}
private bool GetConversionSupported(TypeConverter converter, System.Type conversionType)
{
return (converter.CanConvertFrom(conversionType) && converter.CanConvertTo(conversionType));
}
/// <summary>
/// Returns whether this converter can convert the object to the specified type,
/// using the specified context.
/// </summary>
/// <param name="context">An System.ComponentModel.ITypeDescriptorContext that provides a format context.</param>
/// <param name="destinationType">A System.Type that represents the type you want to convert to.</param>
/// <returns>True if this converter can perform the conversion, False otherwise.</returns>
public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
{
TypeConverter converter = TypeDescriptor.GetConverter(typeof(double));
return(converter.CanConvertTo(context, destinationType));
}
