| public static GetListItemProperties ( object list ) : System.Windows.Forms.PropertyDescriptorCollection | ||
| list | object | |
| return | System.Windows.Forms.PropertyDescriptorCollection | |
/// <include file='doc\ListBindingHelper.uex' path='docs/doc[@for="ListBindingHelper.GetListItemProperties2"]/*' />
public static PropertyDescriptorCollection GetListItemProperties(object dataSource, string dataMember, PropertyDescriptor[] listAccessors)
{
dataSource = GetList(dataSource);
if (!string.IsNullOrEmpty(dataMember))
{
// Find the property on the data source specified by the data member
PropertyDescriptorCollection dsProps = ListBindingHelper.GetListItemProperties(dataSource);
PropertyDescriptor dmProp = dsProps.Find(dataMember, true);
// Error: Property not found - data member is invalid
if (dmProp == null)
{
throw new System.ArgumentException(string.Format(SR.DataSourceDataMemberPropNotFound, dataMember));
}
// Add the data member property to the list accessors
int len = (listAccessors == null) ? 1 : (listAccessors.Length + 1);
PropertyDescriptor[] listAccessors2 = new PropertyDescriptor[len];
listAccessors2[0] = dmProp;
for (int i = 1; i < len; ++i)
{
listAccessors2[i] = listAccessors[i - 1];
}
// Replace old accessors with new accessors
listAccessors = listAccessors2;
}
return(GetListItemProperties(dataSource, listAccessors));
}
void ResetList()
{
if (!is_initialized)
{
return;
}
IList l;
object source = ListBindingHelper.GetList(datasource, datamember);
//
// If original source is null, then create a new object list
// Otherwise, try to infer the list item type
//
if (datasource == null)
{
l = new BindingList <object>();
//list_defaulted = true;
}
else if (source == null)
{
//Infer type based on datasource and datamember,
// where datasource is an empty IEnumerable
// and need to find out the datamember type
Type property_type = ListBindingHelper.GetListItemProperties(datasource) [datamember].PropertyType;
Type t = typeof(BindingList <>).MakeGenericType(new Type [] { property_type });
l = (IList)Activator.CreateInstance(t);
}
else if (source is IList)
{
l = (IList)source;
}
else if (source is IEnumerable)
{
IList new_list = GetListFromEnumerable((IEnumerable)source);
l = new_list == null ? list : new_list;
}
else if (source is Type)
{
Type t = typeof(BindingList <>).MakeGenericType(new Type [] { (Type)source });
l = (IList)Activator.CreateInstance(t);
}
else
{
Type t = typeof(BindingList <>).MakeGenericType(new Type[] { source.GetType() });
l = (IList)Activator.CreateInstance(t);
l.Add(source);
}
SetList(l);
}
/// <include file='doc\ListBindingHelper.uex' path='docs/doc[@for="ListBindingHelper.GetList2"]/*' />
public static object GetList(object dataSource, string dataMember)
{
//
// The purpose of this method is to find a list, given a 'data source' object and a
// decription of some 'data member' property of that object which returns the list.
//
// - If the data source is not a list, we get the list by just querying for the
// current value of that property on the data source itself.
//
// - If the data source is a list, we have to first pick some item from that list,
// then query for the value of that property on the individual list item.
//
dataSource = GetList(dataSource);
if (dataSource == null || dataSource is Type || string.IsNullOrEmpty(dataMember))
{
return(dataSource);
}
PropertyDescriptorCollection dsProps = ListBindingHelper.GetListItemProperties(dataSource);
PropertyDescriptor dmProp = dsProps.Find(dataMember, true);
if (dmProp == null)
{
throw new System.ArgumentException(string.Format(SR.DataSourceDataMemberPropNotFound, dataMember));
}
object currentItem;
if (dataSource is ICurrencyManagerProvider)
{
// Data source is another BindingSource so ask for its current item
CurrencyManager cm = (dataSource as ICurrencyManagerProvider).CurrencyManager;
bool currentKnown = (cm != null && cm.Position >= 0 && cm.Position <= cm.Count - 1);
currentItem = currentKnown ? cm.Current : null;
}
else if (dataSource is IEnumerable)
{
// Data source is an enumerable list, so walk to the first item
currentItem = GetFirstItemByEnumerable(dataSource as IEnumerable);
}
else
{
// Data source is not a list, so just use the data source itself
currentItem = dataSource;
}
// Query the data member property on the chosen object to get back the list
return((currentItem == null) ? null : dmProp.GetValue(currentItem));
}
void ResetDataMemberIfInvalid()
{
if (datamember == String.Empty)
{
return;
}
// if dataMember doesn't refer to a valid property of dataSource, we need to reset it
var property = ListBindingHelper.GetListItemProperties(datasource).Find(datamember, true);
if (property == null)
{
datamember = String.Empty;
OnDataMemberChanged(EventArgs.Empty);
}
}
public virtual PropertyDescriptorCollection GetItemProperties(PropertyDescriptor[] listAccessors)
{
return(ListBindingHelper.GetListItemProperties(list, listAccessors));
}
internal override PropertyDescriptorCollection GetItemProperties(PropertyDescriptor[] listAccessors)
{
return(ListBindingHelper.GetListItemProperties(_dataSource, listAccessors));
}
public override PropertyDescriptorCollection GetItemProperties()
{
return(ListBindingHelper.GetListItemProperties(list));
}