Questions about JPanel?

ggyepcgao

I used the drawLine function on JPanel to draw a series of lines. Now I want to clear these lines. How do I clear them?

hyysios

Draw another line with the background color

ggyepcgao

However, if I have already drawn a lot of lines, I cannot always record the same path. Are you doing reverse order operations?

霜之疯狼

clearRect () clears everything.

ggyepcgao

How to call it? Where is it called?

nanase

clearRect
public abstract void clearRect (int x,
                               int y,
                               int width,
                               int height)
Clears the specified rectangle by filling it with the background color of the current drawing surface. This operation does not use the current paint mode.
Beginning with Java 1.1, the background color of offscreen images may be system dependent. Applications should use setColor followed by fillRect to ensure that an offscreen image is cleared to a specific color.


Parameters:
x-the x coordinate of the rectangle to clear.
y-the y coordinate of the rectangle to clear.
width-the width of the rectangle to clear.
height-the height of the rectangle to clear.





for example:
g.clearRect (0, 0, 400, 400);