Android 用Animation-list实现逐帧动画，最近一段时间看到APP的进度条很多都是ProgressBar然后圆圈里面是一张图片，所以就查看了一下ProgressBar的使用。

1、动画实现

    定义res/anim/loading.xml，例如：

<?xml version="1.0" encoding="UTF-8"?>
<animation-list android:oneshot="false"
  xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:duration="150" android:drawable="@drawable/load_1" />
  <item android:duration="150" android:drawable="@drawable/load_3" />
  <item android:duration="150" android:drawable="@drawable/load_5" />
  <item android:duration="150" android:drawable="@drawable/load_7" />
  <item android:duration="150" android:drawable="@drawable/load_9" />
  <item android:duration="150" android:drawable="@drawable/load_11" />
  <item android:duration="150" android:drawable="@drawable/load_13" />
  <item android:duration="150" android:drawable="@drawable/load_15" />
</animation-list>

2、自定义颜色实现

   定义res/drawable/progress.xml，例如：

<?xml version="1.0" encoding="utf-8"?>
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="0"
    android:pivotX="50%"
    android:pivotY="50%"
    android:toDegrees="360" >

    <shape
        android:innerRadiusRatio="3"
        android:shape="ring"
        android:thicknessRatio="8"
        android:useLevel="false" >
        <gradient
            android:centerColor="#FFFFDC35"
            android:centerY="0.50"
            android:endColor="#FFCE0000"
            android:startColor="#FFFFFFFF"
            android:type="sweep"
            android:useLevel="false" />
    </shape>

</rotate>

3、一张图片

  定义res/drawable/progress_small.xml，例如：

 <ProgressBar
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:indeterminateDrawable="@drawable/progress_small"/>

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
  <rotate android:drawable="@drawable/dialog_progress_round"
   android:fromDegrees="0.0" android:toDegrees="360.0" android:pivotX="50.0%"
   android:pivotY="50.0%" />
</item>
</layer-list>

4、设置背景

	<ProgressBar 
		android:layout_width="wrap_content" 
		android:layout_height="wrap_content"
		android:background="@drawable/load_1"
		/>