透明控件上的透明控件? [英] Transparent Control on Transparent control?

问题描述

我创建了一个TransparentTableLayoutPanel:

I created a TransparentTableLayoutPanel:

class TransTablePanel : TableLayoutPanel
{
    public TransTablePanel()
    {

    }

    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams createParams = base.CreateParams;
            createParams.ExStyle |= 0x00000020; // WS_EX_TRANSPARENT
            return createParams;
        }
    }

    protected override void OnPaintBackground(PaintEventArgs e)
    {
        // Do not paint background.
    }
}

还有一个透明的PictureBox(我尝试只使用 BackColor = Transparent ，但它不起作用)

And a transparent PictureBox (I tried just using BackColor = Transparent and it didn't work)

class TransPicBox : PictureBox
{
    public TransPicBox()
    {

    }

    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams createParams = base.CreateParams;
            createParams.ExStyle |= 0x00000020; // WS_EX_TRANSPARENT
            return createParams;
        }
    }

    protected override void OnPaintBackground(PaintEventArgs e)
    {
        // Do not paint background.
    }
}

这是结果:

第一个单元格是发生此绘制事件的PictureBox:

First cell is the PictureBox with this paint event:

private void picBoxCompass_Paint(object sender, PaintEventArgs e)
    {
        Bitmap b = Properties.Resources.Compass_Rose;
        float rot = PitControl.GetPitbullRotation();
        e.Graphics.DrawImage(rotateImage(b, rot), 0, 0, picBoxCompass.Width, picBoxCompass.Height);
        e.Graphics.DrawLine(LinePen, picBoxCompass.Width / 2, 0, picBoxCompass.Width / 2, picBoxCompass.Height / 2);
        e.Graphics.FillPie(Brushes.Green, picBoxCompass.Width / 2 - 10, picBoxCompass.Height / 2 - 10, 20, 20, 0, 360);
    }

您会看到它不是透明的(黑色背景)，第二个单元格是透明的(您可以看到我窗体的背景图像).

And you can see that is not Transparent (Black Background) and second cell is transparent (you can see my form's background image).

如何使PictureBox透明?

推荐答案

好，Iam添加了对我有用的代码.它不是很好(我想听听它如何做得更好)，但也许会对您有所帮助

Ok Iam adding code that worked for me. Its not very nice(I would like to hear how it could be done better), but maybe it will help you

public class TransPicBox : Control
{
    public Image Image
    {
        get;
        set;
    }

    public TransPicBox()
    {
        SetStyle(ControlStyles.AllPaintingInWmPaint |
                 ControlStyles.SupportsTransparentBackColor, true);
        base.BackColor = Color.FromArgb(0, 0, 0, 0);//Added this because image wasnt redrawn when resizing form
    }

    protected override void OnPaintBackground(PaintEventArgs e)
    {

    }

    protected override void OnPaint(PaintEventArgs e)
    {
        if (Image != null)
        {
            e.Graphics.DrawImage(Image, 0, 0, Image.Width, Image.Height);
        }
    }

    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams cp = base.CreateParams;
            cp.ExStyle |= 0x20;
            return cp;
        }
    }
}

您将需要设置Image属性.

注意:图像应具有透明背景(以* .png格式测试)

Note: Image should be with transparent background (tested with *.png format)

结果:

这篇关于透明控件上的透明控件?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！