键不能为null，关键字：key

[qq_34619798]

private void Form1_Paint(object sender, PaintEventArgs e)
{
bmp = new Bitmap(ClientSize.Width, ClientSize.Height, e.Graphics);
Graphics bmpgraphics = Graphics.FromImage(bmp);
for (int i = 0; i <= 13; i++)
{
bmpgraphics.DrawEllipse(new Pen(Color.FromName(colours[i]), 2),
ballarray[i, 1], ballarray[i, 2], 50, 50);
}
e.Graphics.DrawImageUnscaled(bmp, 0, 0);

//Draw ellipse acording to mouse coords.根据鼠标坐标画图
e.Graphics.DrawEllipse(new Pen(Color.Red), g1, g2, 50, 50);

bmpgraphics.Dispose();
bmp.Dispose();
}
（这只是代码其中一部分）
标红位置调试：键不能为null，关键字：key
不明白怎么修改

[江南小鱼]

Color.FromName 对2L的补充

[tanta]

colors[i]是null吧？自己跟踪下，很简单的。

[Poopaye]

100%是因为colours[i]这个是null

[娃都会打酱油了]

为1L补充