利用Drawable资源 定制改变外观的Seekbar

package com.test.layerdrawable;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}

布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.test.layerdrawable.MainActivity">

<SeekBar
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:max="100"
android:progressDrawable="@drawable/my_bar"
/>

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/layout_logo"
/>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

<!--定义轨道背景色-->
<item android:id="@android:id/background" android:drawable="@drawable/grow" />

<!--定义轨道上已完成的外观-->
<item android:id="@android:id/progress" android:drawable="@drawable/ok" />
</layer-list>

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

<item>
<bitmap
android:gravity="center"
android:src="@drawable/ic_launcher" />
</item>

<item android:top="25dp" android:left="25dp" >
<bitmap android:src="@drawable/ic_launcher" android:gravity="center" />

</item>

<item android:top="50dp" android:left="50dp" >
<bitmap android:src="@drawable/ic_launcher" android:gravity="center" />
</item>
</layer-list>