在图像上创建专色点 [英] Creating spot point on image

问题描述

我正在研究一个用于学习和练习目的的项目..



在图片框中加载图形并在图像上添加一些点。



我的问题是如何删除一个点。



例如..

on我第一次点击鼠标在图像上添加一个点。这里x = 104和y = 108

我的第二次鼠标点击从图像中删除一个点。这里x = 104和y = 108

I am working on a project for study and practise purpose..

load graphic in picture box and add some spot points on image.

my question is how to remove a spot point.

for example..
on my first mouse click add a spot point on image. here x=104 and y=108
on my second mouse click remove a spot point from image. here x=104 and y=108

int x=0;
int y=0;
private void picturebox1_MouseClick(object sender, MouseEventArgs e)
        {
            x = e.X;
            y = e.Y;
            drawPoint();
            ridges++;
            lblttlRdge.Text = ridges.ToString();
        }

        public void drawPoint()
        {
            Graphics g = Graphics.FromHwnd(imazePicZoom.Handle);
            SolidBrush brush = new SolidBrush(Color.Red);
            
            g.FillEllipse(brush, x, y, 5, 5);
            g.Dispose();
        }

我想绘制一个像点（谷歌地图位置标记）选择类型点标记的点。



我尝试了什么：



i以上尝试过代码但在第二次点击时在图像上添加另一个点

I want draw a spot point like (google map location marker) selected type spot marker.

What I have tried:

i have tried above code but on second click add another spot point on image

推荐答案

在绘制点之前必须保存图像区域，然后在绘制新点之前将其恢复spot point：

You have to save the image area around the point before drawing the spot point and restore it before drawing the new spot point:

// Set points to invalid values to indicate that no spot is visible
int x=-1;
int y=-1;
private void picturebox1_MouseClick(object sender, MouseEventArgs 
{
    // Restore area below previous spot point if not first call
    if (x >= 0 && y >= 0)
        restorePoint();
    x = e.X;
    y = e.Y;
    // Save are below new spot point
    savePoint();
    drawPoint();
    ridges++;
    lblttlRdge.Text = ridges.ToString();
}

两个新功能必须使用中心区域 x 和 y 和圆的直径。

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