Specifies the displacement from the top-left corner of the outer border to the top-left corner of the inner border (that is, the thickness of the border) of the original rectangle being redrawn.
Specifies the displacement from the top-left corner of the outer border to the top-left corner of the inner border (that is, the thickness of the border) of the original rectangle being redrawn.
指定重新绘制的矩形的外边界的左上角与内边界的左上角的偏移量（即边界的厚度）。