Android的图形与图像处理之三 逐帧动画（Frame）

定义逐帧动画非常简单，只要在元素中使用子元素定义动画的全部帧，并指定各帧的持续时间即可。

android:onshot控制该动画是否循环播放，设为false则会循环播放

也支持在Java代码中创建逐帧动画，调用addFrame(Drawable frame, int duration)向该动画中添加帧

程序获取AnimationDrawable后，接下来就可用ImageView把AnimationDrawable显示出来

示例代码：

res/anim/fat_po.xml

xml version = "1.0" encoding = "utf-8" ?>

< animation-list xmlns:android = "http://schemas.android.com/apk/res/android"
android:oneshot = "false" >

< item android:drawable = "@drawable/fat_po_f01" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f02" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f03" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f04" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f05" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f06" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f07" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f08" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f09" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f10" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f11" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f12" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f13" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f14" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f15" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f16" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f17" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f18" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f19" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f20" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f21" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f22" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f23" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f24" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f25" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f26" android:duration = "60" />
< item android:drawable = "@drawable/fat_po_f27" android:duration = "60" />

animation-list >

main_activity.xml

< 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" >
    < LinearLayout
        android:layout_width = "match_parent"
        android:layout_height = "wrap_content"
        android:orientation = "horizontal"
        android:gravity = "center" >
        < Button android:id = "@+id/play"
            android:layout_width = "wrap_content"
            android:layout_height = "wrap_content"
            android:text = "start"
            />
        < Button android:id = "@+id/stop"
            android:layout_width = "wrap_content"
            android:layout_height = "wrap_content"
            android:text = "stop"
            />
       
    LinearLayout >

    < ImageView
        android:id = "@+id/anim"
android:layout_width = "match_parent"
android:layout_height = "match_parent"
android:background = "@anim/fat_po"
android:scaleType = "center"
android:layout_gravity = "center_horizontal"
/>
       
   

LinearLayout >

main.java

public class MainActivity extends Activity

{
@Override
public void onCreate(Bundle savedInstanceState)
{
super .onCreate(savedInstanceState);
setContentView(R.layout. activity_main );
// 获取两个按钮
Button play = (Button) findViewById(R.id. play );
Button stop = (Button) findViewById(R.id. stop );
ImageView imageView = (ImageView) findViewById(R.id. anim );
// 获取AnimationDrawable动画对象
final AnimationDrawable anim = (AnimationDrawable) imageView
.getBackground();
play.setOnClickListener( new OnClickListener()
{
@Override
public void onClick(View v)
{
// 开始播放动画
anim.start();
}
});
stop.setOnClickListener( new OnClickListener()
{
@Override
public void onClick(View v)
{
// 停止播放动画
anim.stop();
}
});
}

}