C# 检查picturebox中的坐标是否已更改单击并返回值

下面是我在c#中为picturebox编写的代码。我无法找到一种方法来检查单击坐标（x，y）是否更改，如果更改，circlesize的值应更改为20

杂项：该程序适用于同心圆。圆圈大小为20意味着圆圈应该从小尺寸开始重新绘制

private void picCanvas_Click_1(object sender, EventArgs e)
{
    int x, y;
    if (comboBox1.SelectedItem == "Draw")
    {
            Color color = Color.FromArgb(randClick.Next(0, 256), randClick.Next(0, 256), randClick.Next(0, 256));
            Pen pen = new Pen(color);
            pen.Width = 3;
            paper.DrawEllipse(pen, x1 - circleSize / 2, y1 - circleSize / 2, circleSize, circleSize);

            circleSize += 10; // increase size here
            count += 1;
            MouseEventArgs me = (MouseEventArgs)e;
            Point coordinates = me.Location;
            x = me.X;
            y = me.Y;
    }
    if (comboBox1.SelectedItem == "Change Location")
    {

        MouseEventArgs me = (MouseEventArgs)e;
        Point coordinates = me.Location;
        x = me.X;
        y = me.Y;
        for (; i <= 0; i++)
        {

            for (int j = 0; j < count; j++)
            {
                Color color = Color.FromArgb(randClick.Next(0, 256), randClick.Next(0, 256), randClick.Next(0, 256));
                Pen pen = new Pen(color);
                pen.Width = 3;
                paper.DrawEllipse(pen, x - circleSize / 2, y - circleSize / 2, circleSize, circleSize);

                circleSize += 10; // increase size here
                a = 15;
            }
        }
        if (a == 15)
        {
            Color color = Color.FromArgb(randClick.Next(0, 256), randClick.Next(0, 256), randClick.Next(0, 256));
            Pen pen = new Pen(color);
            pen.Width = 3;
            paper.DrawEllipse(pen, x - circleSize / 2, y - circleSize / 2, circleSize, circleSize);

            circleSize += 10; // increase size here
        }
    }
}

private void picCanvas\u单击\u 1（对象发送方，事件参数e）
{
int x，y；
如果（comboBox1.SelectedItem==“绘制”）
{
Color Color=Color.FromArgb（随机单击.Next（0，256），随机单击.Next（0，256），随机单击.Next（0，256））；
钢笔=新钢笔（颜色）；
笔宽=3；
纸抽屉（钢笔，x1-圆圈大小/2，y1-圆圈大小/2，圆圈大小，圆圈大小）；
circleSize+=10；//此处增加大小
计数+=1；
MouseEventArgs me=（MouseEventArgs）e；
点坐标=me.位置；
x=me.x；
y=me.y；
}
如果（comboBox1.SelectedItem==“更改位置”）
{
MouseEventArgs me=（MouseEventArgs）e；
点坐标=me.位置；
x=me.x；
y=me.y；
对于（；i您可以在
picCanvas\u单击功能范围外定义两个变量，如
prevX
和
prevY

然后在退出
picCanvas\u之前，单击\u 1
（例如，在最后一行）将其设置为

prevX = x;
prevY = y;

然后在
picCanvas\u中检查它们是否已更改，单击\u 1
，然后像这样做

if (prevX != x || prevY != y)
{
  //do what you want
}