Question

我需要帮助才能插入一个我从画框中取出的盒子这是我编码的笔的代码，我不知道如何把它放在图片框中。在图片框的背景上会有一个网络摄像头，我希望我的矩形在图片框内。

private void button1_Click(object sender, EventArgs e)
{
    if (button1.Text == "Start")
    {
        Graphics myGraphics = base.CreateGraphics();
        myGraphics.Clear(Color.White);
        Pen myPen = new Pen(Color.DarkBlue);
        Rectangle rect = new Rectangle(480, 70, 120, 120);
        myGraphics.DrawRectangle(myPen, rect);
        stopWebcam = false;
        button1.Text = "Stop";
    }
    else
    {
        stopWebcam = true;
        button1.Text = "Start";
    }
}

Answer 1

winforms中的痛苦主要在OnPaint事件中完成。您的ButtonClick事件处理程序应该只为OnPaint设置阶段并可能激活它。例如：

public class MyForm : Form
    ...
    private Rectangle? _boxRectangle;   

    private void OnMyButtonClick(object sender, EventArgs e)
    {
        if (button1.Text == "Start")
        {
            _boxRectangle = new Rectangle(...);
            button1.Text = "Stop";
        }
        else
        {
            _boxRectangle = null;
            button1.Text = "Start";
        }
        Invalidate(); // repaint
    }

    protected override OnPaint(PaintEventArgs e)
    {
        if (_boxRectangle != null)
        {
            Graphics g = e.Graphics.
            Pen pen = new Pen(Color.DarkBlue);
            g.DrawRectangle(_boxRectangle);
        }
    }
}

Answer 2

您可能需要将网络摄像头图像绘制到位图缓冲区上，并将其用作图片框的图像。

这是msdn页面，底部是示例：

http://msdn.microsoft.com/en-us/library/system.windows.forms.picturebox.aspx

这是我的方法。

public void GraphicsToPictureBox (ref PictureBox pb, Graphics graphics,
                              Int32 width, Int32 height) 
{
    Bitmap bitmap = new Bitmap(width,height,graphics);
    pb.Image = bitmap;
}

如何将从笔中抽出的Box插入到图片框图像中？

2 个答案: