DrawImage出错，不知道哪里错了。

Question

private int oo,uu;
        private Graphics gs;
private void Form1_Load(object sender, System.EventArgs e)
{
oo=100;
uu=200;
} private void cxh()
{
gs.Clear(this.BackColor);
gs.DrawImage(this.imageList1.Images[0],oo,uu);
}

private void Form1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
{
switch(e.KeyCode)
{
case Keys.Left:
oo=oo-5;
cxh();
break;
case Keys.Right:
oo=oo+5;
cxh();
break;
case Keys.Up:
uu=uu-5;
cxh();
break;
case Keys.Down:
uu=uu+5;
cxh();
break;
}
} private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
    gs=e.Graphics;
cxh();
}

Answer 1

加入以下代码就解决 private void Form1_KeyDown(object sender, KeyEventArgs e)
        {
            //加入这行!!!!!!!!!!!!!!!!
            gs = this.CreateGraphics();            switch (e.KeyCode)
            {
             ...
        }