设置背景渐变色
GradientDrawable gradientDrawable = new GradientDrawable(Orientation.TOP_BOTTOM,
new int[]{Color.RED,Color.YELLOW});
getWindow().setBackgroundDrawable(gradientDrawable);
设置按钮渐变色
GradientDrawable gradientDrawable = new GradientDrawable(Orientation.TOP_BOTTOM,
new int[]{Color.RED,Color.YELLOW});
btn.setBackgroundDrawable(gradientDrawable);
效果图: