C# 窗体样式使用WS_EX_LAYERED后，无法绘制windows控件的解决办法

爱被打了一巴掌 2022-03-29 13:51 525阅读 0赞

根据一副 png 图片绘制半透明窗体时，用了 WS\_EX\_LAYERED 后当前窗体再也不会处理 paint 事件，所以所含的子控件是一辈子也不会画出来的，但是这个控件确实存在，而且可以响应事件 。而此时 windows 画制窗体是使用 UpdateLayeredWindow 这个 api 函数的。

对于按钮，完全可以自己画两个图片然后盖在 button 上面，通过处理 button 的 enter 和 leave 消息来切换者两个图片来表达按钮状态  
  
对于输入框..这个可以用一个让任何人看了都生气地办法，那就是....两个窗体，的确别人就是这么做的  
  
可以用一个空心窗体只显示该显示的控件，然后盖在你的半透明窗体上面，并处理半透明窗体的 move 事件，让另外一个窗体同步移动或者做其它事情

效果如下：

![Image 1][]

以下是一些 C\#代码，Delphi 的就不贴了

主 Form 的代码

![None.gif][]using  System;  
![None.gif][]using  System.Drawing;  
![None.gif][]using  System.Drawing.Imaging;  
![None.gif][]using  System.Collections;  
![None.gif][]using  System.ComponentModel;  
![None.gif][]using  System.Windows.Forms;  
![None.gif][]using  System.Data;  
![None.gif][]using  System.Runtime.InteropServices;  
![None.gif][]  
![None.gif][]namespace  WindowsApplication7  
![ExpandedBlockStart.gif][] \{  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][]publicclass Form1 : System.Windows.Forms.Form  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]private System.ComponentModel.IContainer components;  
![InBlock.gif][]  
![InBlock.gif][]public Form1()  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]//  
![InBlock.gif][]// Windows 窗体设计器支持所必需的  
![InBlock.gif][]//  
![InBlock.gif][] InitializeComponent();  
![InBlock.gif][] FormBorderStyle = FormBorderStyle.None;  
![InBlock.gif][]  
![InBlock.gif][]  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![ExpandedSubBlockStart.gif][]///<summary>  
![InBlock.gif][]/// 清理所有正在使用的资源。  
![ExpandedSubBlockEnd.gif][]///</summary>  
![InBlock.gif][]protectedoverridevoid Dispose( bool disposing )  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]if( disposing )  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]if (components !=null)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] components.Dispose();  
![ExpandedSubBlockEnd.gif][] \}  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]base.Dispose( disposing );  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![ContractedSubBlock.gif][]Windows Form Designer generated code  
![InBlock.gif][]  
![ExpandedSubBlockStart.gif][]///<summary>  
![InBlock.gif][]/// 应用程序的主入口点。  
![ExpandedSubBlockEnd.gif][]///</summary>  
![InBlock.gif][] \[STAThread\]  
![InBlock.gif][]staticvoid Main()  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]  
![InBlock.gif][] Application.Run(new Form1());  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][] Form2 controlFrm =new Form2();  
![InBlock.gif][]privatevoid button1\_Click(object sender, System.EventArgs e)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] MessageBox.Show(controlFrm,controlFrm.textBox1.Text);  
![InBlock.gif][]  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]protectedoverride CreateParams CreateParams  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]get  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] CreateParams cp =base.CreateParams;  
![InBlock.gif][] cp.ExStyle |=0x00080000; // This form has to have the WS\_EX\_LAYERED extended style  
![InBlock.gif][]return cp;  
![ExpandedSubBlockEnd.gif][] \}  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][]privatevoid SetStyle1()  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] Bitmap bm = Image.FromFile(@"Green.png") as Bitmap;  
![InBlock.gif][] Bitmap bm2 = Image.FromFile(@"btn.png") as Bitmap;  
![InBlock.gif][]  
![InBlock.gif][] Graphics g = Graphics.FromImage(bm);  
![InBlock.gif][] g.DrawImage(bm2, 20, 20, new Rectangle(0, 0, 90, 50), GraphicsUnit.Pixel);  
![InBlock.gif][]  
![InBlock.gif][] g.DrawString("by jinjazz", new Font("Ariel", 9, FontStyle.Bold), new SolidBrush(Color.Black), new PointF(40, 50));  
![InBlock.gif][]  
![InBlock.gif][]this.SetBitmap(bm, 255);  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]privatevoid SetStyle2()  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] Bitmap bm = Image.FromFile(@"Green.png") as Bitmap;  
![InBlock.gif][] Bitmap bm2 = Image.FromFile(@"btn.png") as Bitmap;  
![InBlock.gif][]  
![InBlock.gif][] Graphics g = Graphics.FromImage(bm);  
![InBlock.gif][] g.DrawImage(bm2, 15, 15, new Rectangle(7, 140, 100, 50), GraphicsUnit.Pixel);  
![InBlock.gif][]  
![InBlock.gif][] g.DrawString("by jinjazz", new Font("Ariel", 9, FontStyle.Bold), new SolidBrush(Color.Black), new PointF(40, 50));  
![InBlock.gif][]  
![InBlock.gif][]this.SetBitmap(bm, 255);  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][]privatevoid Form1\_Load(object sender, System.EventArgs e)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]  
![InBlock.gif][] controlFrm.Show();  
![InBlock.gif][] SetStyle1();  
![InBlock.gif][]  
![InBlock.gif][]//this.TopMost = true;  
![InBlock.gif][] controlFrm.TopMost =true;  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]privatevoid button1\_MouseEnter(object sender, EventArgs e)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]  
![InBlock.gif][] SetStyle2();  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]privatevoid button1\_MouseLeave(object sender, EventArgs e)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] SetStyle1();  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]publicvoid SetBitmap(Bitmap bitmap, byte opacity)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]if (bitmap.PixelFormat != PixelFormat.Format32bppArgb)  
![InBlock.gif][]thrownew ApplicationException("The bitmap must be 32ppp with alpha-channel.");  
![InBlock.gif][]  
![InBlock.gif][]// The ideia of this is very simple,  
![InBlock.gif][]// 1. Create a compatible DC with screen;  
![InBlock.gif][]// 2. Select the bitmap with 32bpp with alpha-channel in the compatible DC;  
![InBlock.gif][]// 3. Call the UpdateLayeredWindow.  
![InBlock.gif][]  
![InBlock.gif][] IntPtr screenDc = Win32.GetDC(IntPtr.Zero);  
![InBlock.gif][] IntPtr memDc = Win32.CreateCompatibleDC(screenDc);  
![InBlock.gif][] IntPtr hBitmap = IntPtr.Zero;  
![InBlock.gif][] IntPtr oldBitmap = IntPtr.Zero;  
![InBlock.gif][]  
![InBlock.gif][]try  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] hBitmap = bitmap.GetHbitmap(Color.FromArgb(0)); // grab a GDI handle from this GDI+ bitmap  
![InBlock.gif][] oldBitmap = Win32.SelectObject(memDc, hBitmap);  
![InBlock.gif][]  
![InBlock.gif][] Win32.Size size =new Win32.Size(bitmap.Width, bitmap.Height);  
![InBlock.gif][] Win32.Point pointSource =new Win32.Point(0, 0);  
![InBlock.gif][] Win32.Point topPos =new Win32.Point(Left, Top);  
![InBlock.gif][] Win32.BLENDFUNCTION blend =new Win32.BLENDFUNCTION();  
![InBlock.gif][] blend.BlendOp = Win32.AC\_SRC\_OVER;  
![InBlock.gif][] blend.BlendFlags =0;  
![InBlock.gif][] blend.SourceConstantAlpha = opacity;  
![InBlock.gif][] blend.AlphaFormat = Win32.AC\_SRC\_ALPHA;  
![InBlock.gif][]  
![InBlock.gif][] Win32.UpdateLayeredWindow(Handle, screenDc, ref topPos, ref size, memDc, ref pointSource, 0, ref blend, Win32.ULW\_ALPHA);  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]finally  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] Win32.ReleaseDC(IntPtr.Zero, screenDc);  
![InBlock.gif][]if (hBitmap != IntPtr.Zero)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] Win32.SelectObject(memDc, oldBitmap);  
![InBlock.gif][]//Windows.DeleteObject(hBitmap); // The documentation says that we have to use the Windows.DeleteObject... but since there is no such method I use the normal DeleteObject from Win32 GDI and it's working fine without any resource leak.  
![InBlock.gif][] Win32.DeleteObject(hBitmap);  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][] Win32.DeleteDC(memDc);  
![ExpandedSubBlockEnd.gif][] \}  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][]private System.Windows.Forms.Button button1;  
![InBlock.gif][]  
![InBlock.gif][]privatevoid Form1\_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] Win32.ReleaseCapture();  
![InBlock.gif][] Win32.SendMessage(this.Handle.ToInt32(), Win32.WM\_SysCommand, Win32.SC\_MOVE, 0);  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]privatevoid Form1\_Move(object sender, EventArgs e)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] controlFrm.Location =this.Location;  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]privatevoid Form1\_VisibleChanged(object sender, EventArgs e)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] controlFrm.Visible =this.Visible;  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]privatevoid Form1\_FormClosed(object sender, FormClosedEventArgs e)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] controlFrm.Close();  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![ExpandedSubBlockEnd.gif][] \}  
![ExpandedBlockEnd.gif][]\}   
![None.gif][]

显示子控件的Form代码

![None.gif][]using  System;  
![None.gif][]using  System.Collections.Generic;  
![None.gif][]using  System.ComponentModel;  
![None.gif][]using  System.Data;  
![None.gif][]using  System.Drawing;  
![None.gif][]using  System.Text;  
![None.gif][]using  System.Windows.Forms;  
![None.gif][]  
![None.gif][]namespace  WindowsApplication7  
![ExpandedBlockStart.gif][] \{  
![InBlock.gif][]publicpartialclass Form2 : Form  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]public Form2()  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] InitializeComponent();  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]private System.ComponentModel.IContainer components =null;  
![InBlock.gif][]  
![ExpandedSubBlockStart.gif][]///<summary>  
![InBlock.gif][]/// 清理所有正在使用的资源。  
![InBlock.gif][]///</summary>  
![ExpandedSubBlockEnd.gif][]///<param name="disposing">如果应释放托管资源，为 true；否则为 false。</param>  
![InBlock.gif][]protectedoverridevoid Dispose(bool disposing)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]if (disposing && (components !=null))  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] components.Dispose();  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]base.Dispose(disposing);  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![ContractedSubBlock.gif][]Windows 窗体设计器生成的代码  
![InBlock.gif][]  
![InBlock.gif][]private System.Windows.Forms.Button button1;  
![InBlock.gif][]internal System.Windows.Forms.TextBox textBox1;  
![InBlock.gif][]privatevoid button1\_Click(object sender, EventArgs e)  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] MessageBox.Show(this.textBox1.Text);  
![InBlock.gif][]  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]  
![ExpandedSubBlockEnd.gif][] \}  
![ExpandedBlockEnd.gif][]\}

调用 API 的代码

![None.gif][]using  System;  
![None.gif][]using  System.Collections.Generic;  
![None.gif][]using  System.Text;  
![None.gif][]using  System.Runtime.InteropServices;  
![None.gif][]namespace  WindowsApplication7  
![ExpandedBlockStart.gif][] \{  
![InBlock.gif][]class Win32  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]publicenum Bool  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][] False =0,  
![InBlock.gif][] True  
![ExpandedSubBlockEnd.gif][] \};  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][] \[StructLayout(LayoutKind.Sequential)\]  
![InBlock.gif][]publicstruct Point  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]public Int32 x;  
![InBlock.gif][]public Int32 y;  
![InBlock.gif][]  
![ExpandedSubBlockStart.gif][]public Point(Int32 x, Int32 y) \{ this.x = x; this.y = y; \}  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][] \[StructLayout(LayoutKind.Sequential)\]  
![InBlock.gif][]publicstruct Size  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]public Int32 cx;  
![InBlock.gif][]public Int32 cy;  
![InBlock.gif][]  
![ExpandedSubBlockStart.gif][]public Size(Int32 cx, Int32 cy) \{ this.cx = cx; this.cy = cy; \}  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][] \[StructLayout(LayoutKind.Sequential, Pack =1)\]  
![InBlock.gif][]struct ARGB  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]publicbyte Blue;  
![InBlock.gif][]publicbyte Green;  
![InBlock.gif][]publicbyte Red;  
![InBlock.gif][]publicbyte Alpha;  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][] \[StructLayout(LayoutKind.Sequential, Pack =1)\]  
![InBlock.gif][]publicstruct BLENDFUNCTION  
![ExpandedSubBlockStart.gif][]\{  
![InBlock.gif][]publicbyte BlendOp;  
![InBlock.gif][]publicbyte BlendFlags;  
![InBlock.gif][]publicbyte SourceConstantAlpha;  
![InBlock.gif][]publicbyte AlphaFormat;  
![ExpandedSubBlockEnd.gif][] \}  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][]publicconst Int32 ULW\_COLORKEY =0x00000001;  
![InBlock.gif][]publicconst Int32 ULW\_ALPHA =0x00000002;  
![InBlock.gif][]publicconst Int32 ULW\_OPAQUE =0x00000004;  
![InBlock.gif][]  
![InBlock.gif][]publicconstbyte AC\_SRC\_OVER =0x00;  
![InBlock.gif][]publicconstbyte AC\_SRC\_ALPHA =0x01;  
![InBlock.gif][]  
![InBlock.gif][]  
![InBlock.gif][] \[DllImport("user32.dll", ExactSpelling =true, SetLastError =true)\]  
![InBlock.gif][]publicstaticextern Bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, ref Point pptDst, ref Size psize, IntPtr hdcSrc, ref Point pprSrc, Int32 crKey, ref BLENDFUNCTION pblend, Int32 dwFlags);  
![InBlock.gif][]  
![InBlock.gif][] \[DllImport("user32.dll", ExactSpelling =true, SetLastError =true)\]  
![InBlock.gif][]publicstaticextern IntPtr GetDC(IntPtr hWnd);  
![InBlock.gif][]  
![InBlock.gif][] \[DllImport("user32.dll", ExactSpelling =true)\]  
![InBlock.gif][]publicstaticexternint ReleaseDC(IntPtr hWnd, IntPtr hDC);  
![InBlock.gif][]  
![InBlock.gif][] \[DllImport("gdi32.dll", ExactSpelling =true, SetLastError =true)\]  
![InBlock.gif][]publicstaticextern IntPtr CreateCompatibleDC(IntPtr hDC);  
![InBlock.gif][]  
![InBlock.gif][] \[DllImport("gdi32.dll", ExactSpelling =true, SetLastError =true)\]  
![InBlock.gif][]publicstaticextern Bool DeleteDC(IntPtr hdc);  
![InBlock.gif][]  
![InBlock.gif][] \[DllImport("gdi32.dll", ExactSpelling =true)\]  
![InBlock.gif][]publicstaticextern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);  
![InBlock.gif][]  
![InBlock.gif][] \[DllImport("gdi32.dll", ExactSpelling =true, SetLastError =true)\]  
![InBlock.gif][]publicstaticextern Bool DeleteObject(IntPtr hObject);  
![InBlock.gif][]  
![InBlock.gif][] \[DllImport("user32.dll", EntryPoint ="SendMessage")\]  
![InBlock.gif][]publicstaticexternint SendMessage(int hWnd, int wMsg, int wParam, int lParam);  
![InBlock.gif][] \[DllImport("user32.dll", EntryPoint ="ReleaseCapture")\]  
![InBlock.gif][]  
![InBlock.gif][]publicstaticexternint ReleaseCapture();  
![InBlock.gif][]publicconstint WM\_SysCommand =0x0112;  
![InBlock.gif][]publicconstint SC\_MOVE =0xF012;  
![InBlock.gif][]  
![InBlock.gif][]publicconstint SC\_MAXIMIZE =61488;  
![InBlock.gif][]publicconstint SC\_MINIMIZE =61472;  
![ExpandedSubBlockEnd.gif][] \}  
![ExpandedBlockEnd.gif][]\}

[Image 1]: 
[None.gif]: /images/20220329/0f17e624042b4a6c8e919db20b2dd2bc.png
[ExpandedBlockStart.gif]: /images/20220329/6edafd755233499885ae25ca20d800ea.png
[InBlock.gif]: /images/20220329/08bacea84ea94408ab1b5cec4bcda1f6.png
[ExpandedSubBlockStart.gif]: /images/20220329/dccfb30aedd143dfba518853a3136226.png
[ExpandedSubBlockEnd.gif]: /images/20220329/2f9ae57a8de34825a232912ffbf79e9b.png
[ContractedSubBlock.gif]: /images/20220329/95606c029360476b84c0cc226c50e150.png
[ExpandedBlockEnd.gif]: /images/20220329/4c7df83c801d474b861d130e531e64f8.png