Android开发 ShapeDrawable详解

清香茉莉 發表於 2019-7-6 14:18:00

<h1>版权声明</h1>
本文来自博客园，作者：观心静 ，转载请注明原文链接：https://www.cnblogs.com/guanxinjing/p/11142590.html
<div>本文版权归作者和博客园共有，欢迎转载，但必须给出原文链接，并保留此段声明，否则保留追究法律责任的权利。</div>
<h1>前言</h1>
　　ShapeDrawable一开始我以为它是对应xml文件属性里的shape的画图,后来发现我错了... 其实ShapeDrawable更像是一共自由度更大跟偏向与实现draw()方法的一共图像绘制类.所以,它的优点就是可以有更大的自由在代码里绘制一个你想要的图形,缺点是它搞起来有点不太方便,对于只需要简单的图形还不如GradientDrawable方便.
　　ShapeDrawable是靠new一个继承Shape的类,来实现方便你的绘制的(其实底层原理就是View的draw()那套东西).我们可以查到一共有多少个shape,看如下图片:
　　<img src="https://img2018.cnblogs.com/blog/1497956/201907/1497956-20190724210153136-1449759748.png" alt="">
<h1>画圆形 OvalShape</h1>
<div class="cnblogs_code">
<pre> ShapeDrawable shapeDrawable = new ShapeDrawable(new OvalShape());
 shapeDrawable.getPaint().setColor(Color.BLACK);
 Rect rect = new Rect();
 rect.top = 0;
 rect.left = 0;
 rect.bottom = 50;
 rect.right = 50;
 shapeDrawable.setBounds(rect);
 mTextView.setBackground(shapeDrawable);</pre>
</div>
效果图:
<img src="https://img2018.cnblogs.com/blog/1497956/201907/1497956-20190724200826758-1626258536.png" alt="">
 
<h1>画半圆 ArcShape</h1>
<div class="cnblogs_code">
<pre> ShapeDrawable shapeDrawable = new ShapeDrawable(new ArcShape(0,180));//ArcShape参数开始角度startAngle 要画多少角度sweepAngle
 shapeDrawable.getPaint().setColor(Color.BLACK);
 Rect rect = new Rect();
 rect.top = 0;
 rect.left = 0;
 rect.bottom = 50;
 rect.right = 50;
 shapeDrawable.setBounds(rect);
 mTextView.setBackground(shapeDrawable);</pre>
</div>
效果图:
<img src="https://img2018.cnblogs.com/blog/1497956/201907/1497956-20190724201448348-1062504162.png" alt="">
<h1>画矩形 RectShape</h1>
<div class="cnblogs_code">
<pre> ShapeDrawable shapeDrawable = new ShapeDrawable(new RectShape());
 shapeDrawable.getPaint().setColor(Color.BLACK);
 Rect rect = new Rect();
 rect.top = 0;
 rect.left = 0;
 rect.bottom = 50;
 rect.right = 50;
 shapeDrawable.setBounds(rect);
 mTextView.setBackground(shapeDrawable);</pre>
</div>
效果图:
<img src="https://img2018.cnblogs.com/blog/1497956/201907/1497956-20190724201605408-1982162121.png" alt="">
<h1>画内外双层矩形,并且有圆角 RoundRectShape</h1>
<div class="cnblogs_code">
<pre> float[] externalRound = {8, 8, 8, 8, 8, 8, 8, 8};//外部矩形的8个圆角半径,为什么是8个? 因为这个居然是一个角2个半圆组成的(太精细了...)
 RectF distanceRectF = new RectF(10, 10, 10, 10); //内部矩形与外部矩形的距离
 float[] insideRound = {10, 10, 10, 10, 10, 10, 10, 10}; //内部矩形的8个圆角半径值
 ShapeDrawable shapeDrawable = new ShapeDrawable(new RoundRectShape(externalRound, distanceRectF, insideRound));
 shapeDrawable.getPaint().setColor(Color.BLACK);
 Rect rect = new Rect();
 rect.top = 0;
 rect.left = 0;
 rect.bottom = 50;
 rect.right = 50;
 shapeDrawable.setBounds(rect);
 mTextView.setBackground(shapeDrawable);</pre>
</div>
public RoundRectShape(@Nullable float[] outerRadii, @Nullable RectF inset, @Nullable float[] innerRadii)  这个类一共有3个参数,我在上面的注解已经说明了. 
注意!这3个参数都是可以为null的.意思就是,你可以取消任意一个.获得一些其他效果,比如设置第二个和第三个参数为null,你就可以得到一个实心的圆角矩形.
效果图:
<img src="https://img2018.cnblogs.com/blog/1497956/201907/1497956-20190724205145840-1497927080.png" alt="">
 
<h1>画任意形状 PathShape</h1>
  待续....

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本文来自博客园，作者：观心静，转载请注明原文链接：https://www.cnblogs.com/guanxinjing/p/11142590.html 
<div style="color:orange;font-size:16px;">本文版权归作者和博客园共有，欢迎转载，但必须给出原文链接，并保留此段声明，否则保留追究法律责任的权利。 </div>
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来源：https://www.cnblogs.com/guanxinjing/p/11142590.html

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Android开发 ShapeDrawable详解