请教关于GDI+画选择框时出现的一个问题

Question

如图，在鼠标选择窗体上的控件时，选择框在正常情况下应该处于按钮的上层，但我不知道应该怎样做，请各位帮我修改一下！下面是代码：Form4.Designer.cs
---------------------
namespace MapDemo
{
    partial class Form4
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }        #region Windows Form Designer generated code        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.panel1 = new System.Windows.Forms.Panel();
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.panel1.SuspendLayout();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
            this.SuspendLayout();
            // 
            // panel1
            // 
            this.panel1.AutoScroll = true;
            this.panel1.Controls.Add(this.button2);
            this.panel1.Controls.Add(this.button1);
            this.panel1.Controls.Add(this.pictureBox1);
            this.panel1.Dock = System.Windows.Forms.DockStyle.Fill;
            this.panel1.Location = new System.Drawing.Point(0, 0);
            this.panel1.Name = "panel1";
            this.panel1.Size = new System.Drawing.Size(295, 173);
            this.panel1.TabIndex = 3;
            // 
            // pictureBox1
            // 
            this.pictureBox1.Image = global::MapDemo.Properties.Resources.四号线地图;
            this.pictureBox1.Location = new System.Drawing.Point(0, 0);
            this.pictureBox1.Name = "pictureBox1";
            this.pictureBox1.Size = new System.Drawing.Size(575, 767);
            this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.AutoSize;
            this.pictureBox1.TabIndex = 3;
            this.pictureBox1.TabStop = false;
            this.pictureBox1.MouseMove += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseMove);
            this.pictureBox1.MouseDown += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseDown);
            this.pictureBox1.MouseUp += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseUp);
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(53, 52);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(56, 36);
            this.button1.TabIndex = 4;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            // 
            // button2
            // 
            this.button2.Location = new System.Drawing.Point(53, 94);
            this.button2.Name = "button2";
            this.button2.Size = new System.Drawing.Size(56, 29);
            this.button2.TabIndex = 5;
            this.button2.Text = "button2";
            this.button2.UseVisualStyleBackColor = true;
            // 
            // Form4
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(295, 173);
            this.Controls.Add(this.panel1);
            this.Name = "Form4";
            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
            this.Text = "Form4";
            this.Load += new System.EventHandler(this.Form4_Load);
            this.panel1.ResumeLayout(false);
            this.panel1.PerformLayout();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
            this.ResumeLayout(false);        }        #endregion        private System.Windows.Forms.Panel panel1;
        private System.Windows.Forms.PictureBox pictureBox1;
        private System.Windows.Forms.Button button2;
        private System.Windows.Forms.Button button1;    }
}

Answer 1

Form4.cs
-------------------
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;namespace MapDemo
{
    public partial class Form4 : Form
    {
        public Form4()
        {
            InitializeComponent();
        }
        private Point PTStart = Point.Empty; //框选起始点坐标
        private void button1_MouseDown(object sender, MouseEventArgs e)
        {
            //this.DoDragDrop(button1, DragDropEffects.Move);
        }        private void panel1_DragEnter(object sender, DragEventArgs e)
        {
            e.Effect = DragDropEffects.Move;
        }        private void Form4_Load(object sender, EventArgs e)
        {
            // this.pictureBox1.BringToFront();
        }        private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                //框选起始位置
                this.PTStart = e.Location;
            }
        }        private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                int x = Math.Min(this.panel1.ClientSize.Width - 1, Math.Max(0, e.X));
                int y = Math.Min(this.panel1.ClientSize.Height - 1, Math.Max(0, e.Y));
                int width = PTStart.X - x;
                int height = PTStart.Y - y;
                if (width < 0)
                {
                    x = PTStart.X;
                    width = Math.Abs(width);
                }
                if (height < 0)
                {
                    y = PTStart.Y;
                    height = Math.Abs(height);
                }                int checkX = PointToClient(Control.MousePosition).X;
                int checkY = PointToClient(Control.MousePosition).Y;                if (checkX <= 2)
                {
                    if (this.panel1.HorizontalScroll.Value - 10 <= 0)
                        this.panel1.HorizontalScroll.Value = 0;
                    else
                        this.panel1.HorizontalScroll.Value -= 10;
                }
                else if (checkX + 20 >= this.panel1.ClientSize.Width)
                {
                    this.panel1.HorizontalScroll.Value += 10;
                }                if (checkY <= 2)
                {
                    if (this.panel1.VerticalScroll.Value - 10 <= 0)
                        this.panel1.VerticalScroll.Value = 0;
                    else this.panel1.VerticalScroll.Value -= 10;
                }
                else if (checkY + 20 >= panel1.ClientSize.Height)
                {
                    this.panel1.VerticalScroll.Value += 10;
                }
                this.pictureBox1.Refresh();
                Graphics g = this.pictureBox1.CreateGraphics();
                
                g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
                Pen pen = new Pen(Color.Blue, 1);
                pen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash;
                Rectangle GraphicsRectangle = new Rectangle(x, y, width, height);
                g.DrawRectangle(pen, GraphicsRectangle);
                g.Dispose();
            }
        }        private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
        {
            this.pictureBox1.Refresh();
        }
    }
}

Answer 2

to gisfarmer 
不是GIS，就是想实现在控件上框选的效果，不知道该如何做

Answer 3

这个难了 兄弟!
就算实现 也不理想给你个例子
 这样的绘制能勉强覆盖子控件 
         [DllImport("user32.dll")]
        static extern IntPtr GetWindowDC(IntPtr hWnd);        [DllImport("user32.dll")]
        static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);         public Form6()
        {
            InitializeComponent();
        }
        protected override void OnPaint(PaintEventArgs e)
        { 
          
            base.OnPaint(e);
            //这里的绘制能覆盖子控件,但是子控件也会自己绘制哦,希望对你有帮助
            IntPtr vDC = GetWindowDC(this.Handle);
            Graphics vGraphics = Graphics.FromHdc(vDC);
            vGraphics.FillRectangle(Brushes.Red, 60, 60, 55, 70);
            vGraphics.DrawRectangle(Pens.Red, 90, 60, 25, 70); 
        }

Answer 4

确实很麻烦啊，你这样paint的顺序必须是背景->按钮->鼠标，可是第一个和第三个的paint函数是放在一起的……
要是能控制这些绘制函数调用的先后顺序就好了。

Answer 5

to hiddkiller 
效果不太好，和用 “ControlPaint.DrawReversibleFrame(GraphicsRectangle, Color.Yellow, FrameStyle.Dashed);” 方法画出的效果是一样的，没有办法处理低图在滚动条更改的情况下正常显示绘出的矩形。

Answer 6

如果lz只是达到用鼠标绘制一个矩形选择框，然后显示出处于该矩形框内按钮的功能的话，可以试一下以下代码Public Class Form1
    Dim PtStart, pt As Point
    Dim RectSize As Size    Dim WithEvents Pic1 As New PictureBox    Private Sub Pic1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Pic1.MouseDown
        If e.Button = Windows.Forms.MouseButtons.Left Then PtStart = New Point(e.X, e.Y)
    End Sub    Private Sub Pic1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Pic1.MouseMove
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Dim p As Point = PointToScreen(PtStart) : p.Offset(Pic1.Location)
            If pt <> Nothing Then ControlPaint.DrawReversibleFrame(New Rectangle(p.X, p.Y, pt.X - p.X, pt.Y - p.Y), Color.Red, FrameStyle.Dashed)
            pt = PointToScreen(New Point(e.X, e.Y)) : pt.Offset(Pic1.Location)
            ControlPaint.DrawReversibleFrame(New Rectangle(p.X, p.Y, pt.X - p.X, pt.Y - p.Y), Color.Red, FrameStyle.Dashed)
        End If
    End Sub    Private Sub Pic1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Pic1.MouseUp
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Dim p As Point = PointToScreen(PtStart) : p.Offset(Pic1.Location)
            ControlPaint.DrawReversibleFrame(New Rectangle(p.X, p.Y, pt.X - p.X, pt.Y - p.Y), Color.Red, FrameStyle.Dashed)
            Call ControlIsInRect(PtStart, New Point(e.X, e.Y))
            pt = Nothing
        End If
    End Sub    Private Sub ControlIsInRect(ByVal mPoint1 As Point, ByVal mPoint2 As Point)
        Pic1.Refresh()
        If mPoint2.X > mPoint1.X And mPoint2.Y > mPoint1.Y Then
            PtStart = New Point(mPoint1.X, mPoint1.Y) : RectSize = New Size(mPoint2.X - mPoint1.X, mPoint2.Y - mPoint1.Y)
        ElseIf mPoint2.X > mPoint1.X And mPoint2.Y < mPoint1.Y Then
            PtStart = New Point(mPoint1.X, mPoint2.Y) : RectSize = New Size(mPoint2.X - mPoint1.X, mPoint1.Y - mPoint2.Y)
        ElseIf mPoint2.X < mPoint1.X And mPoint2.Y > mPoint1.Y Then
            PtStart = New Point(mPoint2.X, mPoint1.Y) : RectSize = New Size(mPoint1.X - mPoint2.X, mPoint2.Y - mPoint1.Y)
        ElseIf mPoint2.X < mPoint1.X And mPoint2.Y < mPoint1.Y Then
            PtStart = New Point(mPoint2.X, mPoint2.Y) : RectSize = New Size(mPoint1.X - mPoint2.X, mPoint1.Y - mPoint2.Y)
        End If        Dim rect As New Rectangle(PtStart, RectSize)
        For Each btn As MyButton In Pic1.Controls
            If rect.Contains(btn.Left, btn.Top) OrElse rect.Contains(btn.Right, btn.Bottom) Then
                btn.IsInRect = True
            Else
                btn.IsInRect = False
            End If
        Next
    End Sub    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Me.SetStyle(ControlStyles.AllPaintingInWmPaint Or ControlStyles.OptimizedDoubleBuffer Or ControlStyles.UserPaint, True)
        Dim btn As New MyButton
        btn.Text = "Test"
        btn.SetBounds(100, 60, 60, 30)
        Pic1.Controls.Add(btn)
        Pic1.Dock = DockStyle.Fill
        Me.Controls.Add(Pic1)
    End SubEnd Class
Public Class MyButton
    Inherits System.Windows.Forms.Button    Private _IsInRect As Boolean
    Public Property IsInRect() As Boolean
        Get
            Return _IsInRect
        End Get
        Set(ByVal value As Boolean)
            _IsInRect = value
            Me.Invalidate()
        End Set
    End Property    Protected Overrides Sub OnPaint(ByVal pevent As System.Windows.Forms.PaintEventArgs)
        MyBase.OnPaint(pevent)
        If IsInRect Then
            pevent.Graphics.DrawRectangle(Pens.Red, New Rectangle(0, 0, 10, 10))
            pevent.Graphics.DrawRectangle(Pens.Red, New Rectangle(Me.Width - 10, 0, 10, 10))
            pevent.Graphics.DrawRectangle(Pens.Red, New Rectangle(0, Me.Height - 10, 10, 10))
            pevent.Graphics.DrawRectangle(Pens.Red, New Rectangle(Me.Width - 10, Me.Height - 10, 10, 10))
        End If
    End SubEnd Class

Answer 7

如果用ControlPaint.DrawReversibleFrame的话，很难处理当图片大于窗体出现滚动条后，在画矩形框时移动滚动条位置的问题，这个问题我以前问过但一直没有解决：
http://topic.csdn.net/u/20080516/18/f6f82ccd-cc6e-4e65-acb5-b610ee0e3b82.html