如何画一个可选择的线路？ [英] How to draw a selectable line?

问题描述

我想创建一个应用程序，用户能够操纵他划清界线。喜欢的东西删除线或选择它。我应该怎么办呢？

在此先感谢

---

我设法使用硬编码的矩形做到这一点。但我不还是有一个想法如何使用的drawLine（）我可以使用 drawPath 做的去做？点击测试

下面是代码：

 私人布尔selectGraph = FALSE; 
私人矩形myrec =新的Rectangle（50，50，100，100）; 
私有图形克; 
 
私人无效panel1_Paint（对象发件人，PaintEventArgs的E）
 {
 SolidBrush SB =新SolidBrush（Color.Blue）; 
笔P =新朋（Color.Blue，5）; 
 
 e.Graphics.DrawRectangle（P，myrec）; 
 e.Graphics.FillRectangle（SB，myrec）; 
} 
 
私人无效panel1_MouseUp（对象发件人，MouseEventArgs E）
 {
点MPT =新的点（e.X，e.Y）; 
 
如果（e.Button == MouseButtons.Left）
 {
如果（myrec.Contains（MPT））
 {
 selectGraph = TRUE; 
 button1.Enabled = TRUE; 
} 
，否则
 {
 selectGraph = FALSE; 
 button1.Enabled = FALSE; 
} 
} 
的Invalidate（）; 
} 
  

解决方案

好吧，你可以用的东西开始像一个简单的行类：

 公共类线
 {
公共点开始{搞定;组; } 
公共点结束{搞定;组; } 
} 
  

然后，你可以有你的方式：

 专用线线=新线（）; 
 
保护覆盖无效的OnPaint（PaintEventArgs的E）
 {
 e.Graphics.DrawLine（Pens.Red，this.Line.Start，this.Line.End）; 
} 
 
保护覆盖无效的OnMouseMove（MouseEventArgs E）
 {
如果（e.Button == MouseButtons.Left）
 {
 this.Line.Start = e.Location; 
 this.Refresh（）; 
} 
，否则如果（e.Button == MouseButtons.Right）
 {
 this.Line.End = e.Location; 
 this.Refresh（）; 
} 
} 
  

所以基本上然后他们可以删除 this.Line 也许对MiddleButton点击什么的。这应该足以让你开始。

我已经的创建了一个示例，显示如何可以做到这一点。设置一些破发点，看看事情是如何完成的。

I want to create an application which the user is able to manipulate the line he draw. Something like Deleting the line or Selecting it. How should I do that?

Thanks in advance

---

I managed to do it using a hard coded rectangle. But I don't still have an idea how to do it using the drawLine() Can I use drawPath to do the hit test?

Here is the code:

private bool selectGraph = false;
private Rectangle myrec = new Rectangle(50, 50, 100, 100);
private Graphics g;

private void panel1_Paint(object sender, PaintEventArgs e)
    {
        SolidBrush sb = new SolidBrush(Color.Blue);
        Pen p = new Pen(Color.Blue, 5);

        e.Graphics.DrawRectangle(p, myrec);
        e.Graphics.FillRectangle(sb, myrec);
    }

    private void panel1_MouseUp(object sender, MouseEventArgs e)
    {
        Point mPT = new Point(e.X, e.Y);

        if (e.Button == MouseButtons.Left)
        {
            if (myrec.Contains(mPT))
            {
                selectGraph = true;
                button1.Enabled = true;
            }
            else
            {
                selectGraph = false;
                button1.Enabled = false;
            }
        }
        Invalidate();
    }

解决方案

Well you could start with something like a simple Line class:

public class Line
{
    public Point Start { get; set; }
    public Point End { get; set; }
}

Then you could have your form:

private Line Line = new Line();

protected override void OnPaint(PaintEventArgs e)
{
    e.Graphics.DrawLine(Pens.Red, this.Line.Start, this.Line.End);
}

protected override void OnMouseMove(MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        this.Line.Start = e.Location;
        this.Refresh();
    }
    else if (e.Button == MouseButtons.Right)
    {
        this.Line.End = e.Location;
        this.Refresh();
    }
}

So basically then they could delete the this.Line maybe on "MiddleButton" click or something. This should be enough to get you started.

I've created a sample that shows how this can be done. Set some break points and see how things are done.

这篇关于如何画一个可选择的线路？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！