零.引言
PropertyGrid中我们经常看到一些下拉式的编辑方式（Color属性）和弹出式编辑框（字体），这些都是为一些复杂的属性提供的编辑方式，本文主要说明如何实现这样的编辑方式。
一.为属性提供编辑类
弹出式和下拉式是如何实现的呢，这需要为属性提供一个专门的编辑类。.Net为我们提供了一个System.Drawing.Design.UITypeEditor类，它是所有编辑类的基类，从他继承出了诸如ColorEditor、FontEditor的类，因此我们可以在属性框中编辑颜色和字体。定义了这样的类，我们也可以为自己的属性实现弹出式和下拉式编辑方式。
先看一下MSDN中对UITypeEditor的介绍：提供可用于设计值编辑器的基类，这些编辑器可提供用户界面 (UI)，用来表示和编辑所支持的数据类型的对象值。
UITypeEditor 类提供一种基类，可以从该基类派生和进行扩展，以便为设计时环境实现自定义类型编辑器。通常，您的自定义类型编辑器与 PropertyGrid 控件进行交互。在文本框值编辑器不足以有效地选择某些类型的值的情况下，自定义类型编辑器非常有用。
继承者说明：
若要实现自定义设计时 UI 类型编辑器，必须执行下列步骤：
- 定义一个从 UITypeEditor 派生的类。
- 重写 EditValue 方法以处理用户界面、用户输入操作以及值的分配。
- 重写 GetEditStyle 方法，以便将编辑器将使用的编辑器样式的类型通知给“属性”窗口。
通过执行下列步骤，可以为在“属性”窗口中绘制值的表示形式添加附加支持：
- 重写 GetPaintValueSupported 方法以指示编辑器支持显示值的表示形式。
- 重写 PaintValue 方法以实现该值的表示形式的显示。
- 如果编辑器应具有初始化行为，则重写 UITypeEditor 构造函数方法。
二.下拉式编辑方式
接下来我们来实现下拉式编辑方式，接下来举一个具体的例子来说明。
首先假如我们有一个控件类MyControl：
public class MyControl : System.Windows.Forms.UserControl
{
private double _angle; [BrowsableAttribute(true)]
public double Angle
{
get
{ return _angle; }
set
{ _angle = value; }
} public MyControl()
{
this._angle = ;
} protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
e.Graphics.DrawString("The Angle is " + _angle, this.Font, Brushes.Red,,);
}
}
其中有个属性Angle，我们要为其提供下拉式和弹出式编辑方式，当然了，一般都是较为复杂的属性才需要，这里只是为了举例说明。
我们为其设计一个编辑类AngleEditor，在第二节中，继承说明中的第一条和第二条，EditValue和GetEditStyle两个函数，这是必须要重写的：
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
public class AngleEditor : System.Drawing.Design.UITypeEditor
{
public AngleEditor()
{
}
//下拉式还是弹出式
public override System.Drawing.Design.UITypeEditorEditStyle GetEditStyle(System.ComponentModel.ITypeDescriptorContext context)
{
return UITypeEditorEditStyle.DropDown;
} // 为属性显示UI编辑框
public override object EditValue(System.ComponentModel.ITypeDescriptorContext context, System.IServiceProvider provider, object value)
{
//值类型不为double，直接返回value
if (value.GetType() != typeof(double))
return value; //值为double，显示下拉式或弹出编辑框
IWindowsFormsEditorService edSvc = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));
if (edSvc != null)
{
// 显示编辑框并初始化编辑框的值
AngleControl angleControl = new AngleControl((double)value);
edSvc.DropDownControl(angleControl);
// 返回编辑框中编辑的值.
if (value.GetType() == typeof(double))
return angleControl.angle;
}
return value;
} //下面两个函数是为了在PropertyGrid中显示一个辅助的效果
//可以不用重写
public override void PaintValue(System.Drawing.Design.PaintValueEventArgs e)
{
int normalX = (e.Bounds.Width / );
int normalY = (e.Bounds.Height / ); e.Graphics.FillRectangle(new SolidBrush(Color.DarkBlue), e.Bounds.X, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height);
e.Graphics.FillEllipse(new SolidBrush(Color.White), e.Bounds.X + , e.Bounds.Y + , e.Bounds.Width - , e.Bounds.Height - );
e.Graphics.FillEllipse(new SolidBrush(Color.SlateGray), normalX + e.Bounds.X - , normalY + e.Bounds.Y - , , ); double radians = ((double)e.Value * Math.PI) / (double);
e.Graphics.DrawLine(new Pen(new SolidBrush(Color.Red), ), normalX + e.Bounds.X, normalY + e.Bounds.Y,
e.Bounds.X + (normalX + (int)((double)normalX * Math.Cos(radians))),
e.Bounds.Y + (normalY + (int)((double)normalY * Math.Sin(radians))));
} public override bool GetPaintValueSupported(System.ComponentModel.ITypeDescriptorContext context)
{
return true;
}
} // 这里是我们要显示出来的编辑器，把它作为一个内置类
//从UserControl继承，要在上面EditValue函数中使用的
internal class AngleControl : System.Windows.Forms.UserControl
{
public double angle; //编辑的角度
private float x; //鼠标位置
private float y; public AngleControl(double initial_angle)
{
this.angle = initial_angle;
}
//显现时，显示属性的当前值
protected override void OnLoad(EventArgs e)
{
int originX = (this.Width / );
int originY = (this.Height / );
this.x = (float)( * Math.Cos(this.angle * Math.PI / ) + originX);
this.y = (float)( * Math.Sin(this.angle * Math.PI / ) + originY);
base.OnLoad(e);
} //绘制控件，用来显示编辑角度
protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
int originX = (this.Width / );
int originY = (this.Height / ); e.Graphics.DrawEllipse(Pens.Black, originX - , originY - , , );
e.Graphics.DrawLine(Pens.Black, originX, originY, x, y); e.Graphics.DrawString("Angle:" + this.angle, this.Font, Brushes.Red, , );
}
//鼠标移动时设置角度
protected override void OnMouseMove(System.Windows.Forms.MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
int originX = (this.Width / );
int originY = (this.Height / );
double len = Math.Sqrt(Math.Pow(e.X - originX, ) + Math.Pow(e.Y - originY, ));
double h = e.Y - originY;
this.angle = Math.Asin(h / len);
if ((e.X >= originX && e.Y >= originY))
{
this.x = (float)( * Math.Cos(this.angle) + originX);
this.y = (float)( * Math.Sin(this.angle) + originY);
this.angle = this.angle * / Math.PI;
}
else if (e.X < originX && e.Y > originY)
{
this.x = (float)(originX - * Math.Cos(this.angle));
this.y = (float)( * Math.Sin(this.angle) + originY);
this.angle = - this.angle * / Math.PI;
}
else if (e.X < originX && e.Y < originY)
{
this.x = (float)(originX - * Math.Cos(this.angle));
this.y = (float)(originY + * Math.Sin(this.angle));
this.angle = - this.angle * / Math.PI;
}
else if (e.X >= originX && e.Y <= originY)
{
this.x = (float)(originX + * Math.Cos(this.angle));
this.y = (float)(originY + * Math.Sin(this.angle));
this.angle = + this.angle * / Math.PI;
}
this.Invalidate();
} } }
这里有两个类，一个是AngleEditor，他就是我们要用于到属性特性中的编辑类，一个是AngleControl，他是辅助AngleEditor来编辑属性的，也就是说，他就是一个form，当我们编辑属性时，他会显现出来，供我们编辑属性值，可以是textBox，图形，表格，各种方式，只需要最后他返回编辑好的属性值给AngleEditor类。在AngleEditor类中的EditValue函数中，我们会调用AngleControl类，并接受它返回的值。
设计好编辑类后，把它应用到MyControl类中的Angle属性中，在Angle属性中增加特性[EditorAttribute(typeof(AngleEditor), typeof(System.Drawing.Design.UITypeEditor))]，相当于告诉PropertyGrid我们要用AngleEditor来编辑这个属性。
[BrowsableAttribute(true)]
[EditorAttribute(typeof(AngleEditor), typeof(System.Drawing.Design.UITypeEditor))]
public double Angle
{
get
{ return _angle; }
set
{ _angle = value; }
}
好了，现在就可以使用下拉框来编辑我们的Angle属性了，效果如下：
上面那个圆圈就是我们用来编辑角度的。
三.弹出式编辑方式
实现了下拉式，我们来实现弹出式，弹出式和下拉式非常的相像，现在要弹出一个编辑框，因此我们的AngleControl类不能从UserControl继承，而从From继承，让他成为一个对话框，在AngleEditor的EditValue函数中，弹出他并接受返回值，如下：
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
public class AngleEditor : System.Drawing.Design.UITypeEditor
{
public AngleEditor()
{
}
//下拉式还是弹出式
public override System.Drawing.Design.UITypeEditorEditStyle GetEditStyle(System.ComponentModel.ITypeDescriptorContext context)
{
return UITypeEditorEditStyle.Modal;//弹出式
} // 为属性显示UI编辑框
public override object EditValue(System.ComponentModel.ITypeDescriptorContext context, System.IServiceProvider provider, object value)
{
//值类型不为double，直接返回value
if (value.GetType() != typeof(double))
return value; //值为double，显示下拉式或弹出编辑框
IWindowsFormsEditorService edSvc = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));
if (edSvc != null)
{
// 显示编辑框并初始化编辑框的值
AngleControl2 angleControl = new AngleControl2((double)value);
edSvc.ShowDialog(angleControl);
// 返回编辑框中编辑的值.
if (value.GetType() == typeof(double))
return angleControl.angle;
}
return value;
} //下面两个函数是为了在PropertyGrid中显示一个辅助的效果
//可以不用重写
public override void PaintValue(System.Drawing.Design.PaintValueEventArgs e)
{
int normalX = (e.Bounds.Width / );
int normalY = (e.Bounds.Height / ); e.Graphics.FillRectangle(new SolidBrush(Color.DarkBlue), e.Bounds.X, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height);
e.Graphics.FillEllipse(new SolidBrush(Color.White), e.Bounds.X + , e.Bounds.Y + , e.Bounds.Width - , e.Bounds.Height - );
e.Graphics.FillEllipse(new SolidBrush(Color.SlateGray), normalX + e.Bounds.X - , normalY + e.Bounds.Y - , , ); double radians = ((double)e.Value * Math.PI) / (double);
e.Graphics.DrawLine(new Pen(new SolidBrush(Color.Red), ), normalX + e.Bounds.X, normalY + e.Bounds.Y,
e.Bounds.X + (normalX + (int)((double)normalX * Math.Cos(radians))),
e.Bounds.Y + (normalY + (int)((double)normalY * Math.Sin(radians))));
} public override bool GetPaintValueSupported(System.ComponentModel.ITypeDescriptorContext context)
{
return true;
}
} // 这里是我们要显示出来的编辑器，把它作为一个内置类
//从UserControl继承，要在上面EditValue函数中使用的
internal class AngleControl2 : System.Windows.Forms.Form
{
public double angle; //编辑的角度
private float x; //鼠标位置
private float y; public AngleControl(double initial_angle)
{
this.angle = initial_angle;
}
//显现时，显示属性的当前值
protected override void OnLoad(EventArgs e)
{
int originX = (this.Width / );
int originY = (this.Height / );
this.x = (float)( * Math.Cos(this.angle * Math.PI / ) + originX);
this.y = (float)( * Math.Sin(this.angle * Math.PI / ) + originY);
base.OnLoad(e);
} //绘制控件，用来显示编辑角度
protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
int originX = (this.Width / );
int originY = (this.Height / ); e.Graphics.DrawEllipse(Pens.Black, originX - , originY - , , );
e.Graphics.DrawLine(Pens.Black, originX, originY, x, y); e.Graphics.DrawString("Angle:" + this.angle, this.Font, Brushes.Red, , );
}
//鼠标移动时设置角度
protected override void OnMouseMove(System.Windows.Forms.MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
int originX = (this.Width / );
int originY = (this.Height / );
double len = Math.Sqrt(Math.Pow(e.X - originX, ) + Math.Pow(e.Y - originY, ));
double h = e.Y - originY;
this.angle = Math.Asin(h / len);
if ((e.X >= originX && e.Y >= originY))
{
this.x = (float)( * Math.Cos(this.angle) + originX);
this.y = (float)( * Math.Sin(this.angle) + originY);
this.angle = this.angle * / Math.PI;
}
else if (e.X < originX && e.Y > originY)
{
this.x = (float)(originX - * Math.Cos(this.angle));
this.y = (float)( * Math.Sin(this.angle) + originY);
this.angle = - this.angle * / Math.PI;
}
else if (e.X < originX && e.Y < originY)
{
this.x = (float)(originX - * Math.Cos(this.angle));
this.y = (float)(originY + * Math.Sin(this.angle));
this.angle = - this.angle * / Math.PI;
}
else if (e.X >= originX && e.Y <= originY)
{
this.x = (float)(originX + * Math.Cos(this.angle));
this.y = (float)(originY + * Math.Sin(this.angle));
this.angle = + this.angle * / Math.PI;
}
this.Invalidate();
} } }
可以看到，只修改了三个地方：
- AngleEditor类中GetEditStyle函数返回Modal，表明是以弹出式编辑。
- AngleEditor类中EditValue函数中调用编辑控件的方式：
AngleControl2 angleControl = new AngleControl2((double)value);
edSvc.ShowDialog(angleControl);
3.AngleControl2从Form继承，让他显示为对话框，这里为了区别上面的AngleControl类，将其改成了AngleControl2。
现在看看效果：
实现了弹出式的编辑方式。
四.完整代码
下面是完整的代码：
using System;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Design;
using System.Windows.Forms;
using System.Windows.Forms.Design; namespace TestUITypeEditor
{
//编辑器类
[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")]
public class AngleEditor : System.Drawing.Design.UITypeEditor
{
public AngleEditor()
{
} //下拉式还是弹出式
public override System.Drawing.Design.UITypeEditorEditStyle GetEditStyle(System.ComponentModel.ITypeDescriptorContext context)
{
return UITypeEditorEditStyle.DropDown;
//return UITypeEditorEditStyle.Modal;
} //编辑属性值
public override object EditValue(System.ComponentModel.ITypeDescriptorContext context, System.IServiceProvider provider, object value)
{
if (value.GetType() != typeof(double))
return value; //显示编辑框
IWindowsFormsEditorService edSvc = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));
if (edSvc != null)
{
AngleControl angleControl = new AngleControl((double)value);
edSvc.DropDownControl(angleControl);
//AngleControl2 angleControl = new AngleControl2((double)value);
//edSvc.ShowDialog(angleControl); // 获取返回值
if (value.GetType() == typeof(double))
return angleControl.angle;
}
return value;
} //绘制辅助属性显示
public override void PaintValue(System.Drawing.Design.PaintValueEventArgs e)
{
int normalX = (e.Bounds.Width / );
int normalY = (e.Bounds.Height / ); e.Graphics.FillRectangle(new SolidBrush(Color.DarkBlue), e.Bounds.X, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height);
e.Graphics.FillEllipse(new SolidBrush(Color.White), e.Bounds.X + , e.Bounds.Y + , e.Bounds.Width - , e.Bounds.Height - );
e.Graphics.FillEllipse(new SolidBrush(Color.SlateGray), normalX + e.Bounds.X - , normalY + e.Bounds.Y - , , ); double radians = ((double)e.Value * Math.PI) / (double);
e.Graphics.DrawLine(new Pen(new SolidBrush(Color.Red), ), normalX + e.Bounds.X, normalY + e.Bounds.Y,
e.Bounds.X + (normalX + (int)((double)normalX * Math.Cos(radians))),
e.Bounds.Y + (normalY + (int)((double)normalY * Math.Sin(radians))));
} //使用辅助属性显示
public override bool GetPaintValueSupported(System.ComponentModel.ITypeDescriptorContext context)
{
return true;
}
} // 下拉式编辑方式
internal class AngleControl : System.Windows.Forms.UserControl
{
public double angle;
private float x;
private float y; public AngleControl(double initial_angle)
{
this.angle = initial_angle;
} protected override void OnLoad(EventArgs e)
{
int originX = (this.Width / );
int originY = (this.Height / ); this.x = (float)( * Math.Cos(this.angle * Math.PI / ) + originX);
this.y = (float)( * Math.Sin(this.angle * Math.PI / ) + originY); base.OnLoad(e);
} protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
int originX = (this.Width / );
int originY = (this.Height / ); e.Graphics.DrawEllipse(Pens.Black, originX - , originY - , , );
e.Graphics.DrawLine(Pens.Black, originX, originY, x, y); e.Graphics.DrawString("Angle:" + this.angle, this.Font, Brushes.Red, , );
} protected override void OnMouseMove(System.Windows.Forms.MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
int originX = (this.Width / );
int originY = (this.Height / );
double len = Math.Sqrt(Math.Pow(e.X - originX, ) + Math.Pow(e.Y - originY, ));
double h = e.Y - originY;
this.angle = Math.Asin(h / len);
if ((e.X >= originX && e.Y >= originY))
{
this.x = (float)( * Math.Cos(this.angle) + originX);
this.y = (float)( * Math.Sin(this.angle) + originY); this.angle = this.angle * / Math.PI;
}
else if (e.X < originX && e.Y > originY)
{
this.x = (float)(originX - * Math.Cos(this.angle));
this.y = (float)( * Math.Sin(this.angle) + originY); this.angle = - this.angle * / Math.PI;
}
else if (e.X < originX && e.Y < originY)
{
this.x = (float)(originX - * Math.Cos(this.angle));
this.y = (float)(originY + * Math.Sin(this.angle)); this.angle = - this.angle * / Math.PI;
}
else if (e.X >= originX && e.Y <= originY)
{
this.x = (float)(originX + * Math.Cos(this.angle));
this.y = (float)(originY + * Math.Sin(this.angle)); this.angle = + this.angle * / Math.PI;
} this.Invalidate();
}
}
} //弹出式编辑框
internal class AngleControl2 : System.Windows.Forms.Form
{
public double angle;
private float x;
private float y; public AngleControl2(double initial_angle)
{
this.angle = initial_angle;
} protected override void OnLoad(EventArgs e)
{
int originX = (this.Width / );
int originY = (this.Height / ); this.x = (float)( * Math.Cos(this.angle * Math.PI / ) + originX);
this.y = (float)( * Math.Sin(this.angle * Math.PI / ) + originY); base.OnLoad(e);
} protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
int originX = (this.Width / );
int originY = (this.Height / ); e.Graphics.DrawEllipse(Pens.Black, originX - , originY - , , );
e.Graphics.DrawLine(Pens.Black, originX, originY, x, y); e.Graphics.DrawString("Angle:" + this.angle, this.Font, Brushes.Red, , );
} protected override void OnMouseMove(System.Windows.Forms.MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
int originX = (this.Width / );
int originY = (this.Height / );
double len = Math.Sqrt(Math.Pow(e.X - originX, ) + Math.Pow(e.Y - originY, ));
double h = e.Y - originY;
this.angle = Math.Asin(h / len);
if ((e.X >= originX && e.Y >= originY))
{
this.x = (float)( * Math.Cos(this.angle) + originX);
this.y = (float)( * Math.Sin(this.angle) + originY); this.angle = this.angle * / Math.PI;
}
else if (e.X < originX && e.Y > originY)
{
this.x = (float)(originX - * Math.Cos(this.angle));
this.y = (float)( * Math.Sin(this.angle) + originY); this.angle = - this.angle * / Math.PI;
}
else if (e.X < originX && e.Y < originY)
{
this.x = (float)(originX - * Math.Cos(this.angle));
this.y = (float)(originY + * Math.Sin(this.angle)); this.angle = - this.angle * / Math.PI;
}
else if (e.X >= originX && e.Y <= originY)
{
this.x = (float)(originX + * Math.Cos(this.angle));
this.y = (float)(originY + * Math.Sin(this.angle)); this.angle = + this.angle * / Math.PI;
} this.Invalidate();
}
}
} //控件
public class MyControl : System.Windows.Forms.UserControl
{
private double _angle; [BrowsableAttribute(true)]
[EditorAttribute(typeof(AngleEditor), typeof(System.Drawing.Design.UITypeEditor))]
public double Angle
{
get
{ return _angle; }
set
{ _angle = value; }
} public MyControl()
{
this._angle = ;
} protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
e.Graphics.DrawString("The Angle is " + _angle, this.Font, Brushes.Red,,);
}
}
}
新建Window工程，添加该文件，在工具箱中将MyControl控件拖入Form，在属性框中编辑Angle属性。
这里我们把AngleControl和AngleControl2都集成在里面了，当然实际只需选中一种，要实现弹出式，只需按照（三）中的方法，修改AngleEditor中两个地方即可。