setDesignWHD function
配置设计稿尺寸 屏幕 宽,高,密度。 Configuration design draft size screen width, height, density.
Implementation
void setDesignWHD(double? w, double? h, {double? density = 3.0}) {
_designW = w ?? _designW;
_designH = h ?? _designH;
_designD = density ?? _designD;
}