blocks|key|1591324|text|我不是.NET+/+C#专家，但是问题似乎出在PointConverter类的某个地方，这个类被用作System.Drawing.Point类的TypeConverterAttribute。集合编辑器必须在PointConverter类中使用失败的内容。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1591325|我怀疑是PointConverter，因为PointF类没有TypeConverterAttribute，而且它工作得很好。|1591326|在下面的示例中，我使用MSDN中的一些代码拼凑而成，问题是在集合中使用Point类时出现的，而不是使用自定义TypeConverter的MyPoint类时出现的问题。|1591327|using+System;
using+System.Collections.Generic;
using+System.ComponentModel;
using+System.Drawing;
using+System.Data;
using+System.Text;
using+System.Windows.Forms;
using+System.Globalization;

namespace+WindowsControlLibrary1
{
++++public+class+MyTypeConverter+:+TypeConverter
++++{
++++++++//+Overrides+the+CanConvertFrom+method+of+TypeConverter.
++++++++//+The+ITypeDescriptorContext+interface+provides+the+context+for+the
++++++++//+conversion.+Typically,+this+interface+is+used+at+design+time+to+
++++++++//+provide+information+about+the+design-time+container.
++++++++public+override+bool+CanConvertFrom(ITypeDescriptorContext+context,
+++++++++++Type+sourceType)
++++++++{

++++++++++++if+(sourceType+==+typeof(string))
++++++++++++{
++++++++++++++++return+true;
++++++++++++}
++++++++++++return+base.CanConvertFrom(context,+sourceType);
++++++++}
++++++++//+Overrides+the+ConvertFrom+method+of+TypeConverter.
++++++++public+override+object+ConvertFrom(ITypeDescriptorContext+context,
+++++++++++CultureInfo+culture,+object+value)
++++++++{
++++++++++++if+(value+is+string)
++++++++++++{
++++++++++++++++string[]+v+=+((string)value).Split(new+char[]+{+','+});
++++++++++++++++return+new+MyPoint(int.Parse(v[0]),+int.Parse(v[1]));
++++++++++++}
++++++++++++return+base.ConvertFrom(context,+culture,+value);
++++++++}
++++++++//+Overrides+the+ConvertTo+method+of+TypeConverter.
++++++++public+override+object+ConvertTo(ITypeDescriptorContext+context,
+++++++++++CultureInfo+culture,+object+value,+Type+destinationType)
++++++++{
++++++++++++if+(destinationType+==+typeof(string))
++++++++++++{
++++++++++++++++return+((MyPoint)value).X+%2B+","+%2B+((MyPoint)value).Y;
++++++++++++}
++++++++++++return+base.ConvertTo(context,+culture,+value,+destinationType);
++++++++}
++++}

++++[SerializableAttribute]
++++[TypeConverterAttribute(typeof(MyTypeConverter))]
++++public+struct+MyPoint
++++{
++++++++private+int+x;
++++++++private+int+y;

++++++++public+MyPoint(int+_x,+int+_y)
++++++++{
++++++++++++x+=+_x;
++++++++++++y+=+_y;
++++++++}

++++++++public+int+X
++++++++{
++++++++++++get+{+return+x;+}
++++++++++++set+{+x+=+value;+}
++++++++}
++++++++public+int+Y
++++++++{
++++++++++++get+{+return+y;+}
++++++++++++set+{+y+=+value;+}
++++++++}

++++}

++++public+partial+class+UserControl1+:+UserControl
++++{
++++++++private+List<System.Drawing.Point>+points;
++++++++private+List<System.Drawing.PointF>+pointfs;
++++++++private+List<MyPoint>+mypoints;


++++++++public+List<System.Drawing.Point>+PointList
++++++++{
++++++++++++get{+return+points;}
++++++++++++set{+points+=+value;}
++++++++}

++++++++public+List<System.Drawing.PointF>+PointFList
++++++++{
++++++++++++get+{return+pointfs;}
++++++++++++set{pointfs+=+value;}
++++++++}

++++++++public+List<MyPoint>+MyPointList
++++++++{
++++++++++++get+{+return+mypoints;+}
++++++++++++set+{+mypoints+=+value;+}
++++++++}

++++++++public+UserControl1()
++++++++{
++++++++++++InitializeComponent();
++++++++}
++++}
}|code-block|syntax|javascript|1591328|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/ayybcxe5.aspx^0|N|E|1E|K|20|M|2V|E|0|4|E|L|6|U|M|0|Z|5|1I|D|1W|7|B|4|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]|$9|Z|A|10|B|C]|$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|15|8|@$9|16|A|17|B|C]|$9|18|A|19|B|C]|$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|1C|8|@$9|1D|A|1E|B|C]|$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]]|D|@$9|1J|A|1K|1|1L]]|E|$]]|$1|J|3|K|5|L|7|1M|8|@]|D|@]|E|$M|N]]|$1|O|3|-4|5|6|7|1N|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

I'm no .NET / C# expert, but the issue appears to be somewhere within the <code>PointConverter</code> class, which is used as the <code>TypeConverterAttribute</code> for the <code>System.Drawing.Point</code> class. The Collection Editor must be using something within the <code>PointConverter</code> class that fails.

I suspect <code>PointConverter</code> because the <code>PointF</code> class has no <code>TypeConverterAttribute</code>, and it works fine.

In the following example, which I cobbled together using some code from <a href="http://msdn.microsoft.com/en-us/library/ayybcxe5.aspx" rel="nofollow noreferrer">MSDN</a>, your problem is seen when using the <code>Point</code> class in a collection, but not with the <code>MyPoint</code> class which is using a custom <code>TypeConverter</code>.

<pre><code>using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;
using System.Globalization;

namespace WindowsControlLibrary1
{
 public class MyTypeConverter : TypeConverter
 {
 // Overrides the CanConvertFrom method of TypeConverter.
 // The ITypeDescriptorContext interface provides the context for the
 // conversion. Typically, this interface is used at design time to 
 // provide information about the design-time container.
 public override bool CanConvertFrom(ITypeDescriptorContext context,
 Type sourceType)
 {

 if (sourceType == typeof(string))
 {
 return true;
 }
 return base.CanConvertFrom(context, sourceType);
 }
 // Overrides the ConvertFrom method of TypeConverter.
 public override object ConvertFrom(ITypeDescriptorContext context,
 CultureInfo culture, object value)
 {
 if (value is string)
 {
 string[] v = ((string)value).Split(new char[] { ',' });
 return new MyPoint(int.Parse(v[0]), int.Parse(v[1]));
 }
 return base.ConvertFrom(context, culture, value);
 }
 // Overrides the ConvertTo method of TypeConverter.
 public override object ConvertTo(ITypeDescriptorContext context,
 CultureInfo culture, object value, Type destinationType)
 {
 if (destinationType == typeof(string))
 {
 return ((MyPoint)value).X + "," + ((MyPoint)value).Y;
 }
 return base.ConvertTo(context, culture, value, destinationType);
 }
 }

 [SerializableAttribute]
 [TypeConverterAttribute(typeof(MyTypeConverter))]
 public struct MyPoint
 {
 private int x;
 private int y;

 public MyPoint(int _x, int _y)
 {
 x = _x;
 y = _y;
 }

 public int X
 {
 get { return x; }
 set { x = value; }
 }
 public int Y
 {
 get { return y; }
 set { y = value; }
 }

 }

 public partial class UserControl1 : UserControl
 {
 private List&lt;System.Drawing.Point&gt; points;
 private List&lt;System.Drawing.PointF&gt; pointfs;
 private List&lt;MyPoint&gt; mypoints;


 public List&lt;System.Drawing.Point&gt; PointList
 {
 get{ return points;}
 set{ points = value;}
 }

 public List&lt;System.Drawing.PointF&gt; PointFList
 {
 get {return pointfs;}
 set{pointfs = value;}
 }

 public List&lt;MyPoint&gt; MyPointList
 {
 get { return mypoints; }
 set { mypoints = value; }
 }

 public UserControl1()
 {
 InitializeComponent();
 }
 }
}
</code></pre>

blocks|key|3000244|text|Point和PointF之间的区别确实在于PointConverter。为什么这会导致问题是一个相当长的故事，但归根结底，它可以归结为：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3000245|System.ComponentModel.Design.CollectionEditor+.CollectionEditorCollectionForm.SelectionWrapper中的System.ComponentModel.ICustomTypeDescriptor.GetPropertyOwner(PropertyDescriptor)实现只返回this。|offset|length|style|CODE|3000246|根据前面提到的ICustomTypeDescriptor接口方法的MSDN页面，实现应该|3000247|3000248|返回包含由指定属性描述符描述的属性的对象。|blockquote|3000249|3000250|3000251|如果我理解正确的话，在这种情况下，实现与文档相矛盾。|3000252|这是基于我自己的一些研究，所以不要想当然。我在Microsoft+Connect上发布了一篇关于这个问题的报告，所以希望我们在几天内就能确定。当收到答复时，我会报告的。|3000253|entityMap^0|0|0|2M|2O|28|51|4|0|7|L|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|W|8|@$D|X|E|Y|F|G]|$D|Z|E|10|F|G]|$D|11|E|12|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|13|8|@$D|14|E|15|F|G]]|9|@]|A|$]]|$1|J|3|-4|5|6|7|16|8|@]|9|@]|A|$]]|$1|K|3|L|5|M|7|17|8|@]|9|@]|A|$]]|$1|N|3|-4|5|6|7|18|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|19|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|1A|8|@]|9|@]|A|$]]|$1|R|3|S|5|6|7|1B|8|@]|9|@]|A|$]]|$1|T|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]]|U|$]]

The difference between Point and PointF lies indeed with PointConverter. Why this causes a problem is quite a long story, but at the end of the day it boils down to the following:

The <code>System.ComponentModel.ICustomTypeDescriptor.GetPropertyOwner(PropertyDescriptor)</code> implementation in <code>System.ComponentModel.Design.CollectionEditor
.CollectionEditorCollectionForm.SelectionWrapper</code> simply returns <code>this</code>. 

According to the MSDN page of the aforementioned method of the <code>ICustomTypeDescriptor</code> interface, an implementation should

<blockquote>
 Return(s) an object that contains the property described by the specified property descriptor.
</blockquote>

If I understand it correctly, in this case the implementation contradicts the documentation.

This is based on some research of my own, so don't take it for granted. I posted a report of this issue on Microsoft Connect, so hopefully we'll know for sure in a few days. I'll report back when an answer is received.

blocks|key|315499|text|我的解决方案是，在使用集合编辑器编辑列表(点)之前，使用TypeDescriptor.AddAttributes(GetType(Drawing.Point),+New+TypeConverterAttribute())将点的类型转换器设置为空，然后使用TypeDescriptor.AddAttributes(GetType(Drawing.Point),+New+TypeConverterAttribute(GetType(PointConverter)))将类型转换器设置为默认值。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|315500|entityMap^0|S|2A|3J|2X|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

My solution is before you use collectioneditor to edit list(of point), use <code>TypeDescriptor.AddAttributes(GetType(Drawing.Point), New TypeConverterAttribute())</code> to set typeconverter of Point to nothing, and after that use <code>TypeDescriptor.AddAttributes(GetType(Drawing.Point), New TypeConverterAttribute(GetType(PointConverter)))</code> to set typeconverter to default.

I have a custom control which has a property of type <code>Collection&lt;System.Drawing.Point&gt;</code>. When I use <code>CollectionEditor</code> to edit this property, the <code>CollectionEditor</code> window shows <code>"Object does not match target type."</code> for the <code>"X"</code> and <code>"Y"</code> properties. But if I use <code>System.Drawing.PointF</code> instead, there's no failure.

Can anyone please explain why this difference occurs?

CollectionEditor yielding "Object does not match target type." for System.Drawing.Point

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我有一个自定义控件，它有一个Collection<System.Drawing.Point>类型的属性。当我使用CollectionEditor编辑此属性时，CollectionEditor窗口为"X"和"Y"属性显示"Object does not match target type."。但如果我改用System.D...

问CollectionEditor type“对象与目标类型不匹配。”对于System.Drawing.Point
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问CollectionEditor type“对象与目标类型不匹配。”对于System.Drawing.PointEN