Ellipse函数的4个参数分别是什么意思

Declare Function Ellipse Lib "gdi32" Alias "Ellipse" (ByVal hdc As Long, ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
描绘一个椭圆，由指定的矩形围绕。椭圆用当前选择的画笔描绘，并用当前选择的刷子填充

hdc Long，设备场景的句柄
X1，Y1 Long，约束矩形采用逻辑坐标的左上角位置
X2，Y2 Long，约束矩形采用逻辑坐标的右下角位置