C# 将透明图像移动到另一个透明图像上
我定义了C# 将透明图像移动到另一个透明图像上,c#,controls,transparent,C#,Controls,Transparent,我定义了SelecterControl用户控件(背景为透明图像),该控件包含带有透明图像的Roll控件 我想将前部控制移动到选择器控制 执行此操作时,SelecterControl的透明区域不清除 我的完整代码如下: using System; using System.Drawing; using System.Windows.Forms; using System.IO; namespace TestControl { public partial class SelecterContr
SelecterControl
用户控件(背景为透明图像),该控件包含带有透明图像的Roll
控件
我想将前部控制移动到选择器控制
执行此操作时,SelecterControl
的透明区域不清除
我的完整代码如下:
using System;
using System.Drawing;
using System.Windows.Forms;
using System.IO;
namespace TestControl
{
public partial class SelecterControl : UserControl
{
private Roll roll;
public SelecterControl()
{
InitializeComponent();
BackgroundImage = Image.FromStream(new MemoryStream(Convert.FromBase64String("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")));
SetStyle(ControlStyles.SupportsTransparentBackColor, true);
BackColor = Color.Transparent;
}
protected override CreateParams CreateParams
{
get
{
CreateParams cp = base.CreateParams;
cp.ExStyle |= 0x20;
return cp;
}
}
protected override void OnPaintBackground(PaintEventArgs e)
{
}
protected override void OnPaint(PaintEventArgs e)
{
if (BackgroundImage != null)
e.Graphics.DrawImage(BackgroundImage, e.ClipRectangle, e.ClipRectangle, GraphicsUnit.Pixel);
}
#region Roll Horizontal Movement
int strtX;
private void roll_MouseDown(object sender, MouseEventArgs e)
{
strtX = e.X;
}
private void roll_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left)
roll.Left += e.X - strtX;
}
#endregion
#region Designer generated code
private System.ComponentModel.IContainer components = null;
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
private void InitializeComponent()
{
System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(SelecterControl));
this.roll = new MapControl.Roll();
this.SuspendLayout();
//
// roll
//
this.roll.BackColor = System.Drawing.Color.Transparent;
//this.roll.BackgroundImage = ((System.Drawing.Image)(resources.GetObject("roll.BackgroundImage")));
this.roll.Location = new System.Drawing.Point(87, 1);
this.roll.Name = "roll";
this.roll.Size = new System.Drawing.Size(13, 18);
this.roll.TabIndex = 0;
this.roll.MouseDown += new System.Windows.Forms.MouseEventHandler(this.roll_MouseDown);
this.roll.MouseMove += new System.Windows.Forms.MouseEventHandler(this.roll_MouseMove);
//
// SelecterControl
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
//this.BackgroundImage = ((System.Drawing.Image)(resources.GetObject("$this.BackgroundImage")));
this.Controls.Add(this.roll);
this.Name = "SelecterControl";
this.Size = new System.Drawing.Size(251, 22);
this.ResumeLayout(false);
}
#endregion
}
class Roll : Control
{
public Roll()
{
BackgroundImage = Image.FromStream(new MemoryStream(Convert.FromBase64String("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")));
SetStyle(ControlStyles.SupportsTransparentBackColor, true);
BackColor = Color.Transparent;
}
protected override CreateParams CreateParams
{
get
{
CreateParams cp = base.CreateParams;
cp.ExStyle |= 0x20;
return cp;
}
}
protected override void OnPaintBackground(PaintEventArgs e)
{
}
protected override void OnPaint(PaintEventArgs e)
{
if (BackgroundImage != null)
e.Graphics.DrawImage(BackgroundImage, e.ClipRectangle, e.ClipRectangle, GraphicsUnit.Pixel);
}
}
}
这个问题的原因是什么?
谢谢你的帮助
this.roll.Size = new System.Drawing.Size(13, 18);
这是代码中的核心问题,“滚动”控件太小。在CreateParams属性中使用WS_EX_TRANSPARENT标志时,要求Windows确保控件后面的窗口始终先绘制。它为“滚动”控件设置背景像素,这样它就可以在上面绘制自己的内容
问题是,您的滚动控制太小,以至于移动它后,它不够大,无法与以前绘制的散乱像素重叠。它们不再位于滚动控制窗口内。所以它们会留在那里,产生你看到的涂抹效果
避免这种情况的唯一方法是使滚动控制更大,使其始终捕捉这些像素。实际上,与滑块的范围一样大。问题是,您现在失去了使“滚动”成为其自身控件的所有好处。像命中测试这样的事情会变得复杂,你需要知道拇指的位置,才能知道用户点击了它
您还可以创建一个同时绘制滑块和拇指的控件。所需的代码完全相同。由于您使用的系统资源更少,所以它的效率更高,因为windows是昂贵的对象。感谢您解释这个问题,它非常有用。我将卷大小更改为(80100),但不更改。还为
选择器控制添加单击事件,并通过单击更改滚动位置,但不更改。移除roll
控件并在绘制事件上绘制它,但背景的透明部分仍然是涂抹。尝试使父窗体无效以清除背景,但转到无限循环。