Android开发GradientDrawable详解-飞外

GradientDrawable 支持渐变色的Drawable，与shapeDrawable在画型上是类似的，多了支持渐变色。代码上的GradientDrawable比在xml里的shape下gradient属性强大的多，因为shape下gradient属性只支持三色阶渐变，而GradientDrawable可以有更多的色阶渐变。

 GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.LINE); gradientDrawable.setStroke(5, Color.YELLOW);//线的宽度 与 线的颜色 mTextView.setBackground(gradientDrawable);

效果图:

 mTextView.setLayerType(View.LAYER_TYPE_SOFTWARE,null); //要显示虚线一定要关闭硬件加速 GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.LINE); gradientDrawable.setStroke(1, Color.BLACK, 10, 10);//第一个参数为线的宽度 第二个参数是线的颜色 第三个参数是虚线段的长度 第四个参数是虚线段之间的间距长度 mTextView.setBackground(gradientDrawable);

也可以在布局里关闭指定view的硬件加速

android:layerType="software"

效果图:

 GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.OVAL); gradientDrawable.setColor(Color.BLUE); gradientDrawable.setSize(50,50); mTextView.setBackground(gradientDrawable);

效果图:

 GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.OVAL); gradientDrawable.setColor(Color.BLUE); gradientDrawable.setStroke(10,Color.YELLOW); gradientDrawable.setSize(50,50); mTextView.setBackground(gradientDrawable);

效果图:

 GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.RECTANGLE); gradientDrawable.setColor(Color.RED); gradientDrawable.setStroke(10,Color.BLUE); gradientDrawable.setCornerRadius(10); gradientDrawable.setSize(50,50); mTextView.setBackground(gradientDrawable);

效果图:

 GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.LINEAR_GRADIENT); gradientDrawable.setStroke(1, Color.GREEN,30, 30); mTextView.setBackground(gradientDrawable);

效果图:

 int[] colors = {Color.YELLOW, Color.GREEN, Color.BLUE}; GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.RECTANGLE); gradientDrawable.setColors(colors); //添加颜色组 gradientDrawable.setGradientType(GradientDrawable.LINEAR_GRADIENT);//设置线性渐变 gradientDrawable.setSize(50,50); mTextView.setBackground(gradientDrawable);

效果图:

 int[] colors = {Color.YELLOW, Color.GREEN, Color.BLUE}; GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.RECTANGLE); gradientDrawable.setColors(colors); //添加颜色组 gradientDrawable.setGradientType(GradientDrawable.LINEAR_GRADIENT);//设置线性渐变 gradientDrawable.setOrientation(GradientDrawable.Orientation.RIGHT_LEFT);//设置渐变方向 gradientDrawable.setSize(50,50); mTextView.setBackground(gradientDrawable);

效果图:

 int[] colors = {Color.YELLOW, Color.GREEN, Color.BLUE}; GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.RECTANGLE); gradientDrawable.setColors(colors); //添加颜色组 gradientDrawable.setGradientType(GradientDrawable.RADIAL_GRADIENT);//设置半径渐变 gradientDrawable.setGradientRadius(50);//渐变的半径值 gradientDrawable.setSize(50,50); mTextView.setBackground(gradientDrawable);

效果图:

 int[] colors = {Color.YELLOW, Color.GREEN, Color.BLUE}; GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.RECTANGLE); gradientDrawable.setColors(colors); //添加颜色组 gradientDrawable.setGradientType(GradientDrawable.SWEEP_GRADIENT);//设置扫描渐变 gradientDrawable.setGradientCenter(0.5f,0.5f);//渐变中心点 gradientDrawable.setSize(50,50); mTextView.setBackground(gradientDrawable);

gradientDrawable.setDither(true);

可以让渐变的时候颜色阶梯降低,变得更柔和

 GradientDrawable gradientDrawable = new GradientDrawable(); gradientDrawable.setShape(GradientDrawable.RECTANGLE); gradientDrawable.setColor(Color.YELLOW);  gradientDrawable.setAlpha(70);//设置透明度 mTextView.setBackground(gradientDrawable);