未在设计器中序列化的派生集合属性答案

【问题标题】：Derived collection property not serialized in designer未在设计器中序列化的派生集合属性
【发布时间】：2018-11-07 09:05:01
【问题描述】：

我的类派生自具有 MyString 属性的集合，即

  public class CollectionItem
  {
    public bool MyBoolean { get; set; }

    public int MyInteger { get; set; }
  }

  public class MyCollection : List<CollectionItem>
  {
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
    public string MyString { get; set; }

    public MyCollection()
    {
      MyString = "Hello";
    }
  }

这个集合是一个简单的 DummyControl 的一部分，即

  public class DummyControl : System.Windows.Forms.Control
  {
    protected override void OnPaint(PaintEventArgs e)
    {
      base.OnPaint(e);
      e.Graphics.FillRectangle(System.Drawing.Brushes.Yellow, e.ClipRectangle);
    }

    public DummyControl() 
    {
      MyCollection = new MyCollection();

      for (int i = 0; i < 3; i++)
      {
        CollectionItem item = new CollectionItem();
        item.MyInteger = i;
        item.MyBoolean = i > 1;
        MyCollection.Add(item);
      }
    }

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
    public MyCollection MyCollection { get; set; }
  }

当我将此 DummyControl 放在 Windows 窗体上时，除了 MyString 属性之外，所有内容都按预期对窗体设计器进行序列化 - 这就是我得到的：

  // 
  // dummyControl1
  // 
  this.dummyControl1.Location = new System.Drawing.Point(66, 62);
  collectionItem1.MyBoolean = false;
  collectionItem1.MyInteger = 0;
  collectionItem2.MyBoolean = false;
  collectionItem2.MyInteger = 1;
  collectionItem3.MyBoolean = true;
  collectionItem3.MyInteger = 2;
  this.dummyControl1.MyCollection.Add(collectionItem1);
  this.dummyControl1.MyCollection.Add(collectionItem2);
  this.dummyControl1.MyCollection.Add(collectionItem3);
  this.dummyControl1.Name = "dummyControl1";
  this.dummyControl1.Size = new System.Drawing.Size(338, 266);
  this.dummyControl1.TabIndex = 0;
  this.dummyControl1.Text = "dummyControl1";

谁能告诉我我还需要做什么才能将 MyString 属性序列化到表单设计器？

【问题讨论】：

标签： c# .net winforms windows-forms-designer

【解决方案1】：

默认 CodeDom 集合序列化程序不会序列化集合的属性。您可以通过从CodeDomSerializer 派生来创建自定义序列化程序。然后为您的类注册自定义序列化程序：

[DesignerSerializer(typeof(MyCollectionSerializer), typeof(CodeDomSerializer))]
public class MyCollection : List<CollectionItem>

MyCollectionSerializer

此序列化程序序列化MyCollection 的MyString 属性：

using System.CodeDom;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
public class MyCollectionSerializer : CodeDomSerializer
{
    public override object Serialize(IDesignerSerializationManager manager, object value)
    {
        var baseSerializer = (CodeDomSerializer)manager.GetSerializer(
            typeof(MyCollection).BaseType, typeof(CodeDomSerializer));
        var statements = (CodeStatementCollection)baseSerializer.Serialize(manager, value);
        var property = TypeDescriptor.GetProperties(value)[nameof(MyCollection.MyString)];
        if (property.ShouldSerializeValue(value))
        {
            var targetObject = base.GetExpression(manager, value);
            var cpre = new CodePropertyReferenceExpression(targetObject, property.Name);
            var cpe = new CodePrimitiveExpression(property.GetValue(value));
            var cas = new CodeAssignStatement(cpre, cpe);
            statements.Add(cas);
        }
        return statements;
    }
}

那么MyString属性也会被序列化：

// 
// dummyControl1
// 
...
this.dummyControl1.MyCollection.Add(collectionItem1);
this.dummyControl1.MyCollection.Add(collectionItem2);
this.dummyControl1.MyCollection.Add(collectionItem3);
this.dummyControl1.MyCollection.MyString = "Hello";
...

【讨论】：