PropertyGrid—为复杂属性提供下拉式编辑框和弹出式编辑框

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 = 90;
        }

        protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            e.Graphics.DrawString("The Angle is " + _angle, this.Font, Brushes.Red,0,0);
        }
}

　　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 / 2);
            int normalY = (e.Bounds.Height / 2);

            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 + 1, e.Bounds.Y + 1, e.Bounds.Width - 3, e.Bounds.Height - 3);
            e.Graphics.FillEllipse(new SolidBrush(Color.SlateGray), normalX + e.Bounds.X - 1, normalY + e.Bounds.Y - 1, 3, 3);

            double radians = ((double)e.Value * Math.PI) / (double)180;
            e.Graphics.DrawLine(new Pen(new SolidBrush(Color.Red), 1), 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 / 2);
            int originY = (this.Height / 2);
            this.x = (float)(50 * Math.Cos(this.angle * Math.PI / 180) + originX);
            this.y = (float)(50 * Math.Sin(this.angle * Math.PI / 180) + 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 / 2);
            int originY = (this.Height / 2);

            e.Graphics.DrawEllipse(Pens.Black, originX - 50, originY - 50, 100, 100);
            e.Graphics.DrawLine(Pens.Black, originX, originY, x, y);

            e.Graphics.DrawString("Angle:" + this.angle, this.Font, Brushes.Red, 0, 0);
        }
        //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 / 2);
                int originY = (this.Height / 2);
                double len = Math.Sqrt(Math.Pow(e.X - originX, 2) + Math.Pow(e.Y - originY, 2));
                double h = e.Y - originY;
                this.angle = Math.Asin(h / len);
                if ((e.X >= originX && e.Y >= originY))
                {
                    this.x = (float)(50 * Math.Cos(this.angle) + originX);
                    this.y = (float)(50 * Math.Sin(this.angle) + originY);
                    this.angle = this.angle * 180 / Math.PI;
                }
                else if (e.X < originX && e.Y > originY)
                {
                    this.x = (float)(originX - 50 * Math.Cos(this.angle));
                    this.y = (float)(50 * Math.Sin(this.angle) + originY);
                    this.angle = 180 - this.angle * 180 / Math.PI;
                }
                else if (e.X < originX && e.Y < originY)
                {
                    this.x = (float)(originX - 50 * Math.Cos(this.angle));
                    this.y = (float)(originY + 50 * Math.Sin(this.angle));
                    this.angle = 180 - this.angle * 180 / Math.PI;
                }
                else if (e.X >= originX && e.Y <= originY)
                {
                    this.x = (float)(originX + 50 * Math.Cos(this.angle));
                    this.y = (float)(originY + 50 * Math.Sin(this.angle));
                    this.angle = 360 + this.angle * 180 / Math.PI;
                }
                this.Invalidate();
            }          
        }      
}

View Code

　　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 / 2);
            int normalY = (e.Bounds.Height / 2);

            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 + 1, e.Bounds.Y + 1, e.Bounds.Width - 3, e.Bounds.Height - 3);
            e.Graphics.FillEllipse(new SolidBrush(Color.SlateGray), normalX + e.Bounds.X - 1, normalY + e.Bounds.Y - 1, 3, 3);

            double radians = ((double)e.Value * Math.PI) / (double)180;
            e.Graphics.DrawLine(new Pen(new SolidBrush(Color.Red), 1), 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 / 2);
            int originY = (this.Height / 2);
            this.x = (float)(50 * Math.Cos(this.angle * Math.PI / 180) + originX);
            this.y = (float)(50 * Math.Sin(this.angle * Math.PI / 180) + 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 / 2);
            int originY = (this.Height / 2);

            e.Graphics.DrawEllipse(Pens.Black, originX - 50, originY - 50, 100, 100);
            e.Graphics.DrawLine(Pens.Black, originX, originY, x, y);

            e.Graphics.DrawString("Angle:" + this.angle, this.Font, Brushes.Red, 0, 0);
        }
        //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 / 2);
                int originY = (this.Height / 2);
                double len = Math.Sqrt(Math.Pow(e.X - originX, 2) + Math.Pow(e.Y - originY, 2));
                double h = e.Y - originY;
                this.angle = Math.Asin(h / len);
                if ((e.X >= originX && e.Y >= originY))
                {
                    this.x = (float)(50 * Math.Cos(this.angle) + originX);
                    this.y = (float)(50 * Math.Sin(this.angle) + originY);
                    this.angle = this.angle * 180 / Math.PI;
                }
                else if (e.X < originX && e.Y > originY)
                {
                    this.x = (float)(originX - 50 * Math.Cos(this.angle));
                    this.y = (float)(50 * Math.Sin(this.angle) + originY);
                    this.angle = 180 - this.angle * 180 / Math.PI;
                }
                else if (e.X < originX && e.Y < originY)
                {
                    this.x = (float)(originX - 50 * Math.Cos(this.angle));
                    this.y = (float)(originY + 50 * Math.Sin(this.angle));
                    this.angle = 180 - this.angle * 180 / Math.PI;
                }
                else if (e.X >= originX && e.Y <= originY)
                {
                    this.x = (float)(originX + 50 * Math.Cos(this.angle));
                    this.y = (float)(originY + 50 * Math.Sin(this.angle));
                    this.angle = 360 + this.angle * 180 / Math.PI;
                }
                this.Invalidate();
            }
          
        }
      
}

View Code

　　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 / 2);
            int normalY = (e.Bounds.Height / 2);

            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 + 1, e.Bounds.Y + 1, e.Bounds.Width - 3, e.Bounds.Height - 3);
            e.Graphics.FillEllipse(new SolidBrush(Color.SlateGray), normalX + e.Bounds.X - 1, normalY + e.Bounds.Y - 1, 3, 3);

            double radians = ((double)e.Value * Math.PI) / (double)180;
            e.Graphics.DrawLine(new Pen(new SolidBrush(Color.Red), 1), 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 / 2);
            int originY = (this.Height / 2);

            this.x = (float)(50 * Math.Cos(this.angle * Math.PI / 180) + originX);
            this.y = (float)(50 * Math.Sin(this.angle * Math.PI / 180) + originY);

            base.OnLoad(e);
        }

        protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            int originX = (this.Width / 2);
            int originY = (this.Height / 2);

            e.Graphics.DrawEllipse(Pens.Black, originX - 50, originY - 50, 100, 100);
            e.Graphics.DrawLine(Pens.Black, originX, originY, x, y);

            e.Graphics.DrawString("Angle:" + this.angle, this.Font, Brushes.Red, 0, 0);
        }

        protected override void OnMouseMove(System.Windows.Forms.MouseEventArgs e)
        {   
            if (e.Button == MouseButtons.Left)
            {
                int originX = (this.Width / 2);
                int originY = (this.Height / 2);
                double len = Math.Sqrt(Math.Pow(e.X - originX, 2) + Math.Pow(e.Y - originY, 2));
                double h = e.Y - originY;
                this.angle = Math.Asin(h / len);
                if ((e.X >= originX && e.Y >= originY))
                {
                    this.x = (float)(50 * Math.Cos(this.angle) + originX);
                    this.y = (float)(50 * Math.Sin(this.angle) + originY);

                    this.angle = this.angle * 180 / Math.PI;
                }
                else if (e.X < originX && e.Y > originY)
                {
                    this.x = (float)(originX - 50 * Math.Cos(this.angle));
                    this.y = (float)(50 * Math.Sin(this.angle) + originY);

                    this.angle = 180 - this.angle * 180 / Math.PI;
                }
                else if (e.X < originX && e.Y < originY)
                {
                    this.x = (float)(originX - 50 * Math.Cos(this.angle));
                    this.y = (float)(originY + 50 * Math.Sin(this.angle));

                    this.angle = 180 - this.angle * 180 / Math.PI;
                }
                else if (e.X >= originX && e.Y <= originY)
                {
                    this.x = (float)(originX + 50 * Math.Cos(this.angle));
                    this.y = (float)(originY + 50 * Math.Sin(this.angle));

                    this.angle = 360 + this.angle * 180 / 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 / 2);
            int originY = (this.Height / 2);

            this.x = (float)(50 * Math.Cos(this.angle * Math.PI / 180) + originX);
            this.y = (float)(50 * Math.Sin(this.angle * Math.PI / 180) + originY);

            base.OnLoad(e);
        }

        protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            int originX = (this.Width / 2);
            int originY = (this.Height / 2);

            e.Graphics.DrawEllipse(Pens.Black, originX - 50, originY - 50, 100, 100);
            e.Graphics.DrawLine(Pens.Black, originX, originY, x, y);

            e.Graphics.DrawString("Angle:" + this.angle, this.Font, Brushes.Red, 0, 0);
        }

        protected override void OnMouseMove(System.Windows.Forms.MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                int originX = (this.Width / 2);
                int originY = (this.Height / 2);
                double len = Math.Sqrt(Math.Pow(e.X - originX, 2) + Math.Pow(e.Y - originY, 2));
                double h = e.Y - originY;
                this.angle = Math.Asin(h / len);
                if ((e.X >= originX && e.Y >= originY))
                {
                    this.x = (float)(50 * Math.Cos(this.angle) + originX);
                    this.y = (float)(50 * Math.Sin(this.angle) + originY);

                    this.angle = this.angle * 180 / Math.PI;
                }
                else if (e.X < originX && e.Y > originY)
                {
                    this.x = (float)(originX - 50 * Math.Cos(this.angle));
                    this.y = (float)(50 * Math.Sin(this.angle) + originY);

                    this.angle = 180 - this.angle * 180 / Math.PI;
                }
                else if (e.X < originX && e.Y < originY)
                {
                    this.x = (float)(originX - 50 * Math.Cos(this.angle));
                    this.y = (float)(originY + 50 * Math.Sin(this.angle));

                    this.angle = 180 - this.angle * 180 / Math.PI;
                }
                else if (e.X >= originX && e.Y <= originY)
                {
                    this.x = (float)(originX + 50 * Math.Cos(this.angle));
                    this.y = (float)(originY + 50 * Math.Sin(this.angle));

                    this.angle = 360 + this.angle * 180 / 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 = 90;
        }

        protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            e.Graphics.DrawString("The Angle is " + _angle, this.Font, Brushes.Red,0,0);
        }
    }
}

　　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。

(原文)

posted @ 2018-12-29 17:46 quanzhan 阅读(3294) 评论(1) 编辑收藏举报

刷新页面返回顶部

Mentalflow

当不了跑得最快的，就当跑得最久的