自定义控件以选择图片框或面板上的坐标？

Question

我正在开发一个显示DICOM文件的应用程序，现在我进入了MPR。是否有允许在picturebox或面板中有类似行的控件：

http://www.vcreatelogic.com/docs/gcf-2.6.0/html/MPRView.jpg --意图是在移动时移动这一行并执行一些操作，所以我基本上需要某种控件或自定义控件(或者是自定义图标)，以便用户在移动鼠标时能够看到他在picturebox中移动的位置。

谢谢!

更新:下面是我使用的代码：

在图片框的鼠标下：

 if (e.Clicks == 2)
        {

            horizontalstart = new Point(0, e.Y);//Start point of Horizontal line.
            horizontalend = new Point(picbox_mpr.Width, e.Y);//End point of Horizontal line.
            verticalstart = new Point(e.X, 0);//Start point of Vertical line
            verticalend = new Point(e.X, picbox_mpr.Height);//End point of Vertical line.
 }

然后在MouseMove中(在我可以看到图片的地方)，我希望这些线保持固定在所绘制的位置上。

更新:如果用户在图像中双击，则整个想法是绘制线条，如果图像被移动，则将这些线与图像一起移动。

Answer 1

首先，我给出的方法不需要一个自定义控件才能工作，它使用PictureBox提供的两个事件来运行逻辑，但是如果您仍然需要一个自定义控件，那么您应该能够通过将这些方法移植到该控件上进行一些编码。

以下两个字段将保存我们逻辑中的大多数值，

private Point horizontalstart, horizontalend;
private Point verticalstart, verticalend;
private bool drawlines;//Specifies a value whether PictureBox should redraw itself.

让我解释一下这些要点是什么；

第一个Point语句包含水平线的起点和终点，以及

第二个Point语句保存垂直线的起始点和结束点。

当您完成它时，请用MouseMoveEvent of您的PictureBox编写这段代码；

    private void SourcePictureBox_MouseMove(object sender, MouseEventArgs e)
    {
        if(drawlines==true)//If the lines should move.
        {
         horizontalstart = new Point(0, e.Y);//Start point of Horizontal line.
         horizontalend = new Point(SourcePictureBox.Width, e.Y);//End point of Horizontal line.
         verticalstart = new Point(e.X, 0);//Start point of Vertical line
         verticalend = new Point(e.X, SourcePictureBox.Height);//End point of Vertical line.
         SourcePictureBox.Invalidate();//Force PictureBox to repaint.
        }

        else if(drawlines==false)//To lock the lines at current coordinates.
        {
         //Add any code if needed.
        }
    }

其中，SourcePictureBox是我们正在操作的PictureBox，当MouseMoveEvent被引发时，将计算两行的新坐标，并将重绘消息发送给PictureBox，PictureBox使用上面声明和计算的坐标绘制线条。

现在，在Paint事件的PictureBox中编写下面的代码；

    private void SourcePictureBox_Paint(object sender, PaintEventArgs e)
    {
        if (SourcePictureBox.Image != null)
        {
            e.Graphics.DrawLine(SystemPens.WindowText, horizontalstart, horizontalend);//Draw Horizontal line.
            e.Graphics.DrawLine(SystemPens.WindowText, verticalstart, verticalend);//Draw Vertical line.
        }
    }

我还注意到在您的图像中，图像显示的指南比图像稍微小一些，如果是这样的话，那么将MouseMoveEvent事件中的两个语句(不包括Invalidate()事件)替换为下面的语句；

        horizontalstart = new Point(0+10, e.Y);//Start point of Horizontal line.

        horizontalend = new Point(SourcePictureBox.Width-10, e.Y);//End point of Horizontal line.

        verticalstart = new Point(e.X, 0+10);//Start point of Vertical line

        verticalend = new Point(e.X, SourcePictureBox.Height-10);//End point of Vertical line.

但是，这些语句中的新内容是，除了它们通过值10(int)增加两行的起始点和用值10减小端点，从而在PictureBox的边缘和引导的lines.Please注释之间提供了一些空间，如果您想要用您想要的值来替换值10，请记住，这个值不能大于PictureBox大小的一半。

我想说的另一件事是，如果您想要change the colour of guiding lines，将Paint Event中的两个语句的第一个参数替换为类SystemPens.If提供的任何值--类中没有任何值可以满足您的要求，您可以随时为yourself.If创建--您知道如何做，这是最好的选择，如果您需要帮助，请看一看这里.Creating一支新笔，它为您提供了为行会行定义宽度的选项。

更新

“在任何时候，为了阻止线条移动，将上面的drawlines(declared设置为false，恢复其功能，将其设置为true。

这不是一种万无一失的方法，但我希望它足以完成您的工作，并且不要忘记用您的PictureBox名称重命名PictureBox和相关事件。

Answer 2

解决了！

下面是代码：

//Variable declaration:
    private Point horizontalstart, horizontalend, verticalstart, verticalend, horizontalstart_initialpoint, horizontalend_initialpoint, verticalstart_initialpoint, verticalend_initialpoint;
    System.Drawing.Pen redline= new System.Drawing.Pen(System.Drawing.Color.Red);
    private Point redlinemovedpoints = Point.Empty;
    private Point redline_panstart = Point.Empty;


 void picbox_mpr_MouseDown(object sender, MouseEventArgs e)
    {
        redline_panstart = new Point(e.X, e.Y); //saves the point from where you pan the picture

 if (e.Clicks == 2) //if the user double clicks, then the red line is drawn in the PictureBox
        {
            horizontalstart = new Point(0, e.Y);//Start point of Horizontal line.
            horizontalend = new Point(picbox_mpr.Width, e.Y);//End point of Horizontal line.
            verticalstart = new Point(e.X, 0);//Start point of Vertical line
            verticalend = new Point(e.X, picbox_mpr.Height);//End point of Vertical line.

            //fixed reference points, this is used to store where the line was drawn initially.
            horizontalstart_initialpoint= horizontalstart;
            horizontalend_initialpoint = horizontalend;
            verticalstart_initialpoint = verticalstart;
            verticalend_initialpoint = verticalend;

            picbox_mpr.Invalidate(); // Draw the lines (see paint event at the bottom)
        }


 void picbox_mpr_MouseMove(object sender, MouseEventArgs e)
    {

 if (e.Button == MouseButtons.Left & pan) // don't worry about pan, is a variable I use to determine if the user is dragging the mouse.
        {

            redlinemovedpoints = new Point(e.Location.X - redline_panstart.X,
                    e.Location.Y - redline_panstart.Y); // this is the X and Y points move

            horizontalstart = new Point(horizontalstart_initialpoint.X + redlinemovedpoints.X, horizontalstart_initialpoint.Y+redlinemovedpoints.Y);
            horizontalend = new Point(picbox_mpr.Width, horizontalend_initialpoint.Y + redlinemovedpoints.Y);
            verticalstart = new Point(verticalstart_initialpoint.X + redlinemovedpoints.X, verticalstart_initialpoint.Y + redlinemovedpoints.Y);
            verticalend = new Point(verticalstart_initialpoint.X + redlinemovedpoints.X, picbox_mpr.Height);

            picbox_mpr.Invalidate(); //re draws the lines, this time moved X or Y depending the pan.

        }

}

void picbox_mpr_MouseUp(object sender, MouseEventArgs e)
    {

        //save the line points positions where after panning the image
        horizontalstart_initialpoint = horizontalstart;
        horizontalend_initialpoint = horizontalend;
        verticalstart_initialpoint = verticalstart;
        verticalend_initialpoint = verticalend;
     }

 private void picbox_mpr_Paint(object sender, PaintEventArgs e)
    {
        Image tmp = (Image)img.RenderImage(0);
        e.Graphics.Clear(System.Drawing.Color.Black);
        e.Graphics.DrawImage(tmp, movingPoint);
        tmp.Dispose();
        e.Graphics.DrawLine(redline, horizontalstart, horizontalend);//Draw Horizontal line.
        e.Graphics.DrawLine(redline, verticalstart, verticalend);//Draw Horizontal line.

     }