protected override Expression VisitMember(MemberExpression node)
{
if (node.Expression is ParameterExpression)
{
//到达根节点，并且一定是左枝
if (ExpressionUtil.IsEntityMember(node.Member))
{
//x.User.Book.Id
string tableName = ExpressionUtil.GetEntityTableName(ExpressionUtil.GetMemberType(node.Member));
if (string.IsNullOrWhiteSpace(tableName))
{
throw new Exception("解析出错");
}
string alia = _aliaTableNameMap[tableName];
field = _memberStack.Pop().Name;
_conditionStack.Push("[" + alia + "].[" + field + "]");
_conditionStack.Push("@" + field);
}
else
{
//按照属性处理
field = node.Member.Name;
if (_memberStack.Count > 0)
{
//有属性要转换为sql语句
var propertyInfo = (PropertyInfo)_memberStack.Pop();
if (propertyInfo.PropertyType.FullName == "System.DateTime" && propertyInfo.PropertyType.Assembly.GlobalAssemblyCache)
{
//该属性为日期时间型，可进行转换
_conditionStack.Push("CONVERT(NVARCHAR(20),[" + field + "],101)");
}
else
{
throw new NotImplementedException("不允许使用当前属性取值：" + propertyInfo.PropertyType.Name + "，" + propertyInfo.Name);
}
}
else if (_memberStack.Count > 0)
{
//有方法要转换为sql语句
var method = _memberStack.Pop();
if (method.Name == "ToDateTime" && method.DeclaringType.Assembly.GlobalAssemblyCache)
{
_conditionStack.Push("CONVERT(NVARCHAR(20),[" + field + "],101)");
}
else
{
throw new NotSupportedException("不支持指定方法的转换：" + method.Name);
}
}
else
{
_conditionStack.Push("[" + field + "]");
}
_conditionStack.Push("@" + field);
}
}
else if (node.Expression == null)
{
//一定是静态成员，例如：x=>DateTime.Now中的Now，直接取出值
object value = null;
if (node.Member.MemberType == MemberTypes.Field)
{
var fieldInfo = node.Member as FieldInfo;
value = fieldInfo.GetValue(null);
}
else
{
var propertyInfo = node.Member as PropertyInfo;
value = propertyInfo.GetValue(null, null);
}
while (_memberStack.Count > 0)
{
var member = _memberStack.Pop();
if (member.MemberType == MemberTypes.Field)
{
value = ((FieldInfo)member).GetValue(value);
}
else if (member.MemberType == MemberTypes.Property)
{
value = ((PropertyInfo)member).GetValue(value, null);
}
else
{
throw new NotSupportedException("未知的成员类型：" + member.MemberType);
}
}
//if (node.Member.MemberType == MemberTypes.Field)
//{
// var fieldInfo = node.Member as FieldInfo;
// _list.Add(fieldInfo.GetValue(null));
//}
//else
//{
// var propertyInfo = node.Member as PropertyInfo;
// _list.Add(propertyInfo.GetValue(null, null));
//}
_list.Add(_conditionStack.Peek(), value);
}
else if (node.Expression is ConstantExpression)
{
//引用的局部变量
//var constExp = node.Expression as ConstantExpression;
//var field = constExp.Value.GetType().GetField(node.Member.Name);
//var rootValue = field.GetValue(constExp.Value);
//while (_propertyStack.Count > 0)
//{
// var property = _propertyStack.Pop();
// rootValue = property.GetValue(rootValue, null);
//}
//_paramStack.Push(rootValue);
ObjectValueExpressionVisitor visitor = new ObjectValueExpressionVisitor();
visitor.Visit(node);
if (visitor.Value is Array || visitor.Value is IEnumerable)
{
var rootValue = visitor.Value;
var list = rootValue as IList;
object result = rootValue;
while (_memberStack.Count > 0)
{
var memberInfo = _memberStack.Pop();
if (memberInfo.MemberType == MemberTypes.Method)
{
var method = memberInfo as MethodInfo;
IEnumerable <object> args = null;
//if (method.Arguments[0] is ConstantExpression)
//{
// args = mce.Arguments.Select(x => ((ConstantExpression)x).Value);
// result = mce.Method.Invoke(rootValue, args.ToArray());
//}
//else
//{
// visitor = new ObjectValueExpressionVisitor();
// visitor.Visit(mce.Arguments[0]);
// var extensionArgs = mce.Arguments.Skip(1).Select(x => ((ConstantExpression)x).Value).ToList();
// extensionArgs.Insert(0, visitor.Value);
// result = mce.Method.Invoke(null, extensionArgs.ToArray());
//}
}
}
if (_memberStack.Count > 0)
{
//MethodCallExpression mce = _memberStack.Pop();
//IEnumerable<object> args = null;
//if (mce.Arguments[0] is ConstantExpression)
//{
// args = mce.Arguments.Select(x => ((ConstantExpression)x).Value);
// result = mce.Method.Invoke(rootValue, args.ToArray());
//}
//else
//{
// visitor = new ObjectValueExpressionVisitor();
// visitor.Visit(mce.Arguments[0]);
// var extensionArgs = mce.Arguments.Skip(1).Select(x => ((ConstantExpression)x).Value).ToList();
// extensionArgs.Insert(0, visitor.Value);
// result = mce.Method.Invoke(null, extensionArgs.ToArray());
//}
}
_list.Add(_conditionStack.Peek(), result);
//_constStack.Push(rootValue);
}
else
{
_constStack.Push(visitor.Value);
}
_paramNameStack.Push(node.Member.Name);
}
else if (node.Expression is MemberExpression)
{
if (!ExpressionReflector.IsEntityPropertyType(ExpressionUtil.GetMemberType(((MemberExpression)node.Expression).Member)))
{
//x=>x.User.Book.Id
_memberStack.Push(node.Member);
}
else
{
//var a=false;x=>a这种情况
}
}
else
{
_memberStack.Push(node.Member);
}
return(base.VisitMember(node));
}
/// <summary>
/// 是否是实体成员
/// </summary>
/// <param name="memberInfo"></param>
/// <returns></returns>
public static bool IsEntityMember(MemberInfo memberInfo)
{
return(!ExpressionReflector.IsEntityPropertyType(GetMemberType(memberInfo)));
}
/// <summary>
/// 该类型是否可以作为实体属性的类型
/// </summary>
/// <param name="type"></param>
/// <returns></returns>
internal static bool IsEntityPropertyType(Type type)
{
return(ExpressionReflector.IsEntityPropertyType(type));
}
/// <summary>
/// 初始化表格的列
/// </summary>
/// <param name="gridView">要初始化的DataGridView</param>
/// <param name="autoSizeMode">行模式</param>
/// <param name="dataSource">数据源</param>
public static void InitColumns(DataGridView gridView, DataGridViewAutoSizeColumnsMode autoSizeMode = DataGridViewAutoSizeColumnsMode.Fill)
{
gridView.ColumnHeadersDefaultCellStyle.WrapMode = DataGridViewTriState.False;
var value = gridView.DataSource;
gridView.AutoSizeColumnsMode = autoSizeMode;
gridView.EditMode = DataGridViewEditMode.EditProgrammatically;
gridView.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
gridView.AllowUserToAddRows = false;
gridView.AllowUserToDeleteRows = false;
if (!(value is IList))
{
return;
}
var type = value.GetType().GetGenericArguments().FirstOrDefault();
if (type != null)
{
var pis = type.GetProperties(BindingFlags.Instance | BindingFlags.Public).Where(x => ExpressionReflector.IsEntityPropertyType(x.PropertyType));
var displayType = typeof(DataGridColumnAttribute);
foreach (var item in pis)
{
var attrs = item.GetCustomAttributes(displayType, false);
if (attrs.Length <= 0)
{
continue;
}
var dn = attrs[0] as DataGridColumnAttribute;
DataGridViewColumn column;
if (gridView.AutoGenerateColumns)
{
column = gridView.Columns[item.Name];
if (column == null)
{
continue;
}
if (dn == null)
{
continue;
}
column.HeaderText = dn.DisplayName;
column.Visible = dn.Visible;
if (dn.Width <= 0 || dn.Width == -1)
{
continue;
}
try
{
column.Width = dn.Width;
}
catch
{
}
}
else
{
column = new DataGridViewTextBoxColumn();
column.HeaderText = dn.DisplayName;
column.Visible = dn.Visible;
column.Width = dn.Width;
gridView.Columns.Add(column);
}
}
}
}