动态可订制属性的 PropertyGrid

来源：互联网发布：华为机顶盒软件下载编辑：程序博客网时间：2024/06/06 01:52

文章转载，原文来自：http://blog.csdn.net/akron/article/details/2750566

在VB6, VC++, C#.net 里都可以见到一个属性设计器，用来编辑修改 object 的属性。C# 下提供了一个属性设计器 PropertyGrid，其使用极其简单，只要

grid.SelectedObject = myOjbect;

就可以把myOjbect 的所有属性显示出来。不过很多时候我们不希望如此，因为欠缺一种灵活性。我希望可以自由的控制需要编辑的内容。能做的这一点，再配合可编辑的 ListView，可以很好的解决复杂内容的修改编辑问题。

首先是定义一个CProperty, 用来设置 object 在PropertyGrid 中的内容，还得定义一个实现 ICustomTypeDescriptor 接口的容器CPropertyCollection, 最后定制一个 PropertyDescriptor, 用来描述 PropertyGrid 接口方法。

public class CPropertyCollection : CCollection<CProperty>, ICustomTypeDescriptor

{

public void Add(CProperty value)

{

base.Put(value.Name, value);

}

#region "TypeDescriptor"

public String GetClassName()

{

return TypeDescriptor.GetClassName(this, true);

}

public AttributeCollection GetAttributes()

{

return TypeDescriptor.GetAttributes(this, true);

}

public String GetComponentName()

{

return TypeDescriptor.GetComponentName(this, true);

}

public TypeConverter GetConverter()

{

return TypeDescriptor.GetConverter(this, true);

}

public EventDescriptor GetDefaultEvent()

{

return TypeDescriptor.GetDefaultEvent(this, true);

}

public PropertyDescriptor GetDefaultProperty()

{

return TypeDescriptor.GetDefaultProperty(this, true);

}

public object GetEditor(Type editorBaseType)

{

return TypeDescriptor.GetEditor(this, editorBaseType, true);

}

public EventDescriptorCollection GetEvents(Attribute[] attributes)

{

return TypeDescriptor.GetEvents(this, attributes, true);

}

public EventDescriptorCollection GetEvents()

{

return TypeDescriptor.GetEvents(this, true);

}

public PropertyDescriptorCollection GetProperties(Attribute[] attributes)

{

PropertyDescriptor[] propDes = new PropertyDescriptor[this.Count];

for (int i = 0; i < this.Count; i++) {

CProperty prop = (CProperty) this[i];

propDes[i] = new CPropertyDescriptor(ref prop, attributes);

}

return new PropertyDescriptorCollection(propDes);

}

public PropertyDescriptorCollection GetProperties()

{

return TypeDescriptor.GetProperties(this, true);

}

public object GetPropertyOwner(PropertyDescriptor pd)

{

return this;

}

#endregion

}

public class CProperty

{

private string m_Name = string.Empty;

private bool m_bReadOnly = false;

private bool m_bVisible = true;

private object m_Value = null;

private string m_Category = string.Empty;

TypeConverter m_Converter = null;

object m_Editor = null;

public CProperty(string name, object value)

{

m_Name = name;

m_Value = value;

}

public CProperty(string name, object value, bool bReadOnly, bool bVisible)

{

m_Name = name;

m_Value = value;

m_bReadOnly = bReadOnly;

m_bVisible = bVisible;

}

public bool ReadOnly

{

get { return m_bReadOnly; }

set { m_bReadOnly = value; }

}

public virtual TypeConverter Converter

{

get { return m_Converter; }

set { m_Converter = value; }

}

public string Name

{

get { return m_Name; }

set { m_Name = value; }

}

public bool Visible

{

get { return m_bVisible; }

set { m_bVisible = value; }

}

public virtual object Value

{

get { return m_Value; }

set { m_Value = value; }

}

public string Category

{

get { return m_Category; }

set { m_Category = value; }

}

public virtual object Editor

{

get { return m_Editor; }

set { m_Editor = value; }

}

public class CPropertyDescriptor : PropertyDescriptor

{

CProperty m_Property;

public CPropertyDescriptor(ref CProperty property, Attribute[] attrs)

: base(property.Name, attrs)

{

m_Property = property;

}

#region PropertyDescriptor "region"

public override bool CanResetValue(object component)

{

return false;

}

public override Type ComponentType

{

get { return null; }

}

public override object GetValue(object component)

{

return m_Property.Value;

}

public override string Description

{

get { return m_Property.Name; }

}

public override string Category

{

get { return m_Property.Category; }

}

public override string DisplayName

{

get { return m_Property.Name; }

}

public override bool IsReadOnly

{

get { return m_Property.ReadOnly; }

}

public override TypeConverter Converter

{

get { return m_Property.Converter; }

}

public override void ResetValue(object component)

{

}

public override bool ShouldSerializeValue(object component)

{

return false;

}

public override void SetValue(object component, object value)

{

m_Property.Value = value;

}

public override Type PropertyType

{

get { return m_Property.Value.GetType(); }

}

public override object GetEditor(Type editorBaseType)

{

return m_Property.Editor == null ? base.GetEditor(editorBaseType) : m_Property.Editor;

}

#endregion

}

下面的事情变得很简单：

private void Form_Load(object sender, EventArgs e)

{

CProperty myProp1 = new CProperty("Test1", "test");

MyProp1.Category = "test";

CProperty myProp2 = new CProperty("Test2", 1);

myProp2.Editor = new System.Drawing.Design.ColorEditor();

myProperties.Add(myProp1);

myProperties.Add(myProp2);

grid.SelectedObject = myProperties;

}

可以看到通过CProperty.Editor 可以使用各种的编辑器，甚至自定义的编辑器（从 UITypeEditor 派生，msdn 中有例子）。另一个要点是CProperty.Converter, 用来自定义如何进行类型转换，例如，enum 类型在PropertyGrid 中用 List 编辑，如果不想事先定义一个enum, 可以用自己的 TypeConverter 来实现功能更强大的编辑方法。

public class ListConverter : StringConverter

{

object[] m_Objects;

public ListConverter(object[] objects)

{

m_Objects = objects;

}

public override bool GetStandardValuesSupported(ITypeDescriptorContext context)

{

return true;

}

public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)

{

return true;

}

public override

System.ComponentModel.TypeConverter.StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)

{

return new StandardValuesCollection(m_Objects);

}

使用ListConverter：

CProperty myProp = new CProperty("Test", "test2");

myProp.Converter = new ListConverter(new string[] { "test1", "test2", "test3" });

当click 属性 Test 时，会弹出一个 List 框。重载 TypeConverter 的 ConvertTo and ConvertFrom 可以获得更多的功能。

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