1

你好 stackoverflow 社区。我已经尝试寻找类似的问题，但我只发现了关于闪烁的问题，这与我遇到的问题不同。

PictureBox每当我在面板上移动它们时，我都需要帮助防止es 拖尾。我正在制作的应用程序类似于 MS Paint。当我单击 a 时，PictureBox我可以使用以下命令单击并拖动它：

private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{            
    x = e.X;
    y = e.Y;
}

private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        pictureBox1.Left += (e.X - x);
        pictureBox1.Top += (e.Y - y);
    }
}

并且我没有单击的其他图片框被绘制到 DoubleBuffered 面板，使用：

private void panel1_Paint(object sender, PaintEventArgs e)
{
    foreach (PictureBox pb in pboxes)
    {
        if (!pb.Visible)
        {
            e.Graphics.DrawImage(pb.BackgroundImage, new Rectangle(pb.Location, pb.Size));
        }
    }
}

出于某种原因，当我拖动PictureBox它的背景图像时，它会拖过绘制的面板。

奇怪的是，这只发生在 Paint 事件上。如果我要制作面板的背景图像，则移动PictureBox不会拖尾。只有当我Image在面板上绘制 s 时才会发生这种情况。

这是一个例子在此处输入图像描述

我将不胜感激任何帮助，谢谢。

我简化了代码，这样更容易理解。（拖尾效应仍然存在）

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;
using System.Collections;

namespace WindowsFormsApplication1

{

public partial class Form1 : Form
{

    int x;
    int y;

    public Form1()
    {
        InitializeComponent();
        pictureBox1.Show();
        pictureBox2.Hide();
        pictureBox3.Hide();
    }

    private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
    {            
        x = e.X;
        y = e.Y;
        panel1.Invalidate();
    }

    private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            pictureBox1.Left += (e.X - x);
            pictureBox1.Top += (e.Y - y);
        }
    }

    private void panel1_Paint(object sender, PaintEventArgs e)
    {
        e.Graphics.DrawImage(pictureBox2.BackgroundImage, new Rectangle(pictureBox2.Location, pictureBox2.Size));
        e.Graphics.DrawImage(pictureBox3.BackgroundImage, new Rectangle(pictureBox3.Location, pictureBox3.Size));
    }


}}

它使用这个 doubleBuffered 面板类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public class DoubleBufferPanel : Panel
    {


        public DoubleBufferPanel()
        {

            // Set the value of the double-buffering style bits to true.
            this.DoubleBuffered = true;



            this.SetStyle(ControlStyles.DoubleBuffer | ControlStyles.UserPaint |
             ControlStyles.AllPaintingInWmPaint, true);

            this.UpdateStyles();

        }


    }

}

现在我的代码需要 3PictureBox和 1DoubleBuffered面板。

表格被最大化，Panel1.size = (2000, 1200);并且PictureBox size = (700, 700)将每个PictureBoxes背景图像设置为随机的大细节图像。当我移动时会出现拖尾效应，pictureBox1我每次都可以重现。

4

2 回答 2

0

您是否尝试过从 OnPaint 处理程序调用 base 的 OnPaint，或者从 MouseMove 执行选择性的无效/刷新？

于 2012-08-26T17:49:45.870 回答
0

我知道这是几年前的事了，但我今天也遇到了类似的麻烦。我正在单击并拖动 aPictureBox以放大图像部分。这些问题通过正确的操作顺序得到解决：尺寸、移动、油漆。我通过以下方式解决了这个问题：

  1. PictureBox在表单Load事件期间实例化

  2. 活动期间搬迁PictureBox及其Location财产MouseMove

  3. PictureBox搬迁后失效

  4. 在事件期间重绘Paint，这是通过触发的Invalidate()

  5. 我有一个自定义形状 ( Region) PictureBox，这是在VisibleChange活动期间设置的。*

  6. 仅在按下鼠标左键且图像足够大时才可见 ( ) 。PictureBox*Visible == true

    * = 可选

这是我的代码的修改摘录。我希望它们足够相关。

public Form1()
{
    InitializeComponent();

    this.Paint += new System.Windows.Forms.PaintEventHandler(Form1_Paint);
    Main_PictureBox.Paint += new PaintEventHandler(Main_PictureBox_Paint);
    Main_PictureBox.MouseDown += new MouseEventHandler(StartZoom);
    Zoom_PictureBox.MouseDown += new MouseEventHandler(StartZoom);
    Main_PictureBox.MouseMove += new MouseEventHandler(MoveZoom);
    Main_PictureBox.MouseUp += new MouseEventHandler(EndZoom);
    Main_PictureBox.MouseLeave += new EventHandler(EndZoom);
    Zoom_PictureBox.MouseUp += new MouseEventHandler(EndZoom);
    Zoom_PictureBox.VisibleChanged += new EventHandler(Zoom_PictureBox_VisibleRegion);
    Zoom_PictureBox.Paint += new PaintEventHandler(Zoom_PictureBox_Paint);
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
    int H = flowLayoutPanel1.Height - flowLayoutPanel1.Margin.Size.Height;
    Main_PictureBox.MinimumSize = new Size(0, 0);
    Main_PictureBox.MaximumSize = new Size(flowLayoutPanel1.Width, H);
}
private void Main_PictureBox_Paint(object sender, PaintEventArgs e)
{
    Main_PictureBox.Parent.MaximumSize = Main_PictureBox.Size + Main_PictureBox.Margin.Size;
}
private void DisplayImage(object sender, EventArgs e)
{
    Image img = ((PictureBox)sender).Image;

    int W = img.Width;
    int H = img.Height;
    float ratio = (float)W / (float)H;

    Main_PictureBox.Image = img;
    Main_PictureBox.Size = new Size(W, H);
    float TestRatio = ((float)Main_PictureBox.Width / (float)Main_PictureBox.Height);
    if (TestRatio < ratio)
        Main_PictureBox.Height = (int)((float)Main_PictureBox.Width / ratio);
    else if (TestRatio > ratio)
        Main_PictureBox.Width = (int)((float)Main_PictureBox.Height * ratio);
}
private void Zoom_PictureBox_VisibleRegion(object sender, EventArgs e)
{
    using (var gp = new System.Drawing.Drawing2D.GraphicsPath())
    {
        gp.AddEllipse(new Rectangle(0, 0, this.Zoom_PictureBox.Width, this.Zoom_PictureBox.Height));
        this.Zoom_PictureBox.Region = new Region(gp);
    }
}
private void Zoom_PictureBox_Paint(object sender, PaintEventArgs e)
{
    e.Graphics.DrawImage(Main_PictureBox.Image, e.ClipRectangle, cropRectangle, GraphicsUnit.Pixel);
}
private void StartZoom(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left && scale > 1.25)
    {
        int dX = Zoom_PictureBox.Width / 2;
        int dY = Zoom_PictureBox.Height / 2;
        Zoom_PictureBox.Visible = true;
        Zoom_PictureBox.Location = new Point(e.X - dX, e.Y - dY);
    }
}
private void MoveZoom(object sender, MouseEventArgs e)
{
    if (Main_PictureBox.Image != null)
    {
        Zoom_PictureBox.Visible = (e.Button == MouseButtons.Left && scale > 1.25);
        if (Zoom_PictureBox.Visible && e.Button == MouseButtons.Left)
        {
            int dX = Zoom_PictureBox.Width / 2;
            int dY = Zoom_PictureBox.Height / 2;

            Zoom_PictureBox.Location = new Point(e.X - dX, e.Y - dY);
            Zoom_PictureBox.Invalidate();
        }
    }
}
private void EndZoom(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
        EndZoom();
}
private void EndZoom(object sender, EventArgs e)
{
    EndZoom();
}
private void EndZoom()
{
    Zoom_PictureBox.Visible = false;
}
private Rectangle cropRectangle
{
    get
    {
        if (Main_PictureBox.Image != null)
        {
            Point origin = Main_PictureBox.PointToScreen(new Point(0, 0));
            float X = (float)(MousePosition.X - origin.X);
            return new Rectangle(
                (int)(scale * X) - Zoom_PictureBox.Width / 2,
                (int)(scale * (float)(MousePosition.Y - origin.Y)) - Zoom_PictureBox.Height / 2,
                Zoom_PictureBox.Width,
                Zoom_PictureBox.Height);
        }
        else
            return new Rectangle();
    }
}
private float scale
{
    get
    {
        if (Main_PictureBox.Image != null)
            return (float)Main_PictureBox.Image.Height / (float)Main_PictureBox.Height;
        else
            return 0;
    }
}
于 2016-07-01T04:34:23.357 回答