用C#改写C++,实现窗体渐变半透明效果！【再加100分=200分】

benbenRH 2009-03-26 09:25:45

用C#实现
http://www.souzz.net/html/edu/C1/12649.html
这种效果。
200分都不够的可以再加！非常感谢！

...全文

430 15 打赏收藏转发到动态举报

写回复

用AI写文章

15 条回复

切换为时间正序

请发表友善的回复…

发表回复

yymao2005 2010-01-04

打赏
举报

有什么办法能让form半透明，里面的控件不透明呢？

tmd456 2009-03-26

打赏
举报

private void timer_Tick(object sender,EventArgs e)
{
this.Opacity+=0.1
}

benbenRH 2009-03-26

打赏
举报

[Quote=引用 6 楼 cbgn 的回复:]
http://blog.csdn.net/zhoufoxcn/archive/2008/06/16/2554064.aspx
[/Quote]
五楼的方法还没有看，但是六楼所说的不是我要实现的，你这个渐变是时间上的，而我要求的是空间上的渐变。时间上的我知道怎么实现，但是还是谢谢！
五楼的方法等一下再研究一下！

cbgn 2009-03-26

打赏
举报

http://blog.csdn.net/zhoufoxcn/archive/2008/06/16/2554064.aspx

gomoku 2009-03-26

打赏
举报

1、设置窗口的格式为WS_EX_LAYERED
2、用UpdateLayeredWindow() API进行Alpha混合

3、Alpha值控制透明程度
4、Bitmap mask = GetMaskImage()可以换成从文件中加载，不过文件必须是带ALPHA通道的32位图像。



using System;

using System.Drawing;

using System.Windows.Forms;

using System.Runtime.InteropServices;



public class Form1 : Form

{

    public Form1()

    {

        this.TopMost = true;

        this.MouseClick += delegate { MessageBox.Show("quiting..."); this.Close(); };

    }



    static void Main()

    {

        Application.Run(new Form1());

    }



    protected override CreateParams CreateParams

    {

        get

        {

            CreateParams parameter = base.CreateParams;

            parameter.ExStyle |= WS_EX_LAYERED;

            return parameter;

        }

    }



    protected override void OnLoad(EventArgs e)

    {

        Bitmap mask = GetMaskImage();

        this.Size = mask.Size;



        byte blendOp = 0;                  // AC_SRC_OVER

        byte blendFlags = 0;               // 0

        byte sourceConstantAlpha = 255;    // 0 ... 255

        byte alphaFormat = 1;              // AC_SRC_ALPHA

        int blend = BitConverter.ToInt32(new byte[] { blendOp, blendFlags, sourceConstantAlpha, alphaFormat }, 0);



        Size size = mask.Size;

        Point point = Point.Empty;



        IntPtr desktopDC = IntPtr.Zero;

        IntPtr memDC = IntPtr.Zero;

        IntPtr imgObject = IntPtr.Zero;

        try

        {

            desktopDC = GetDC(IntPtr.Zero);

            memDC = CreateCompatibleDC(desktopDC);

            imgObject = mask.GetHbitmap(Color.Black);



            IntPtr oldObject = SelectObject(memDC, imgObject);

            UpdateLayeredWindow(this.Handle, desktopDC, ref point, ref size, memDC, ref point, 0, ref blend, ULW_ALPHA);

            SelectObject(memDC, oldObject);

        }

        finally

        {

            DeleteObject(imgObject);

            DeleteDC(memDC);

            ReleaseDC(IntPtr.Zero, desktopDC);

        }

    }



    Bitmap GetMaskImage()

    {

        Bitmap mask = new Bitmap(250, 250);

        string text = "Click me";



        using (Font font = new Font(FontFamily.GenericSerif, 30))

        using (Graphics g = Graphics.FromImage(mask))

        {

            g.FillEllipse(Brushes.Purple, 0, 0, 200, 300);

            g.DrawString(text, font, Brushes.DarkBlue, 12, 102);

            g.DrawString(text, font, Brushes.LightBlue, 10, 100);



        }

        for (int y = 0; y < mask.Height; y++)

        {

            for (int x = 0; x < mask.Width; x++)

            {

                Color c = mask.GetPixel(x, y);

                if (c.B > 0) mask.SetPixel(x, y, Color.FromArgb( (255-y) & 0xff, c));

            }

        }

        return mask;

    }



    const int ULW_ALPHA = 0x02;

    const int WS_EX_LAYERED = 0x80000;



    [DllImport("user32")]

    static extern bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, ref Point pptDst, ref Size psize, IntPtr hdcSrc, ref Point pprSrc, int crKey, ref int pblend, int dwFlags);



    [DllImport("gdi32")]

    static extern IntPtr CreateCompatibleDC(IntPtr hDC);



    [DllImport("user32")]

    static extern IntPtr GetDC(IntPtr hWnd);



    [DllImport("user32")]

    static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);



    [DllImport("gdi32")]

    static extern bool DeleteDC(IntPtr hdc);



    [DllImport("gdi32")]

    static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);



    [DllImport("gdi32")]

    static extern bool DeleteObject(IntPtr hObject);

}