鼠标向下移动

Question

What's wrong with it?

    private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
    {
        position_x = e.Location.X;
        position_y = e.Location.Y;
    }

    private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
    {
     int position_x_next = e.Location.X;
     int position_y_next = e.Location.Y;

     if (position_x_next < position_x)
     {
         MessageBox.Show("it moved left");
     }
    }

Answer 1

You need to keep track of the previous position of the mouse and the new position.

Create 2 new variables, mouseIsDown and previousMouseX .

In your MouseDown handler, set mouseIsDown to true and previousMouseX to mouse.x and set it to false in a MouseUp handler.

Then, add a MouseMove handler that checks if previousMouseX is greater than mouse.x . If so, the mouse is moving left. Make sure to update previousMouseX here as well.

Answer 2

您应该每次都检查MouseEventArgs以查看按钮何时按下并捕获X和Y坐标-如果X坐标小于最后一次，则可以告诉它向左移动。

Answer 3

It's pretty simple actually. Store the position it was in the last move event (it's in the e parameter). Then compare the current position with the last one. If its X coordinate is to the left it's moving left.

If you want to distinguish moving exactly left from moving diagonally left-up for instance, you should add a condition to check if the variation in the Y axis is small enough to account for user imprecision.

Answer 4

The cheesy way:

Set a flag in the mouse down event IsMouseDown = true. In the mouse move event check if IsMouseDown == true In MouseUp set IsMouseDown = true

Answer 5

What about the mouse move event and passing the X and Y cordinates

http://msdn.microsoft.com/en-us/library/system.windows.forms.control.mousemove(VS.71).aspx

http://www.java2s.com/Code/CSharp/Event/MouseMovement.htm