Android 自定义帧动画

Android 自定义帧动画

Android L ； Android Studio

帧动画

和gif图片类似，顺序播放准本好的图片文件；图片资源在xml文件中配置好

将图片按照预定的顺序一张张切换，即成动画

Android 帧动画例子

可以把动画放进子线程中启动，也可以在主线程直接启动动画

主线程更容易控制动画的启停；

子线程需要关注线程的状态，不好控制动画

主线程的UI不能放进子线程去设置；即子线程不能直接修改主UI；

屏幕旋转后，activity重启；动画也就停止了；

在 AndroidManifest.xml 设置 configChanges 即可

<activity
android:name=".MainActivity"
android:configChanges="orientation|keyboardHidden|screenSize"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

动画资源

图片资源来自Android L Launcher3 res

图片全部放在 res/drawable 里面

配置文件 transition_stack.xml

oneshot="false"

动画会一直循环播放下去

<animation-list
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/transition_stack" android:oneshot="false">
<item android:drawable="@drawable/stack_00000" android:duration="30" />
<item android:drawable="@drawable/stack_00001" android:duration="30" />
......
</animation-list>

Java代码

1.取得ImageView

2.为ImageView设置背景资源文件

3.把ImageView的背景赋给动画AnimationDrawable

public class MainActivity extends AppCompatActivity {
private ImageView mTransitionIcon;
private ImageView mStackIcon;
private AnimationDrawable frameAnimation;
private AnimationDrawable stackAnimation;
private Thread stackThread;
private Button stopButton;
public boolean action = false;

private TextView tvState;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
tvState = (TextView) findViewById(R.id.tv_state);

stopButton = (Button) findViewById(R.id.btn_stop);
Button btn1 = (Button) findViewById(R.id.btn1);
Button btn2 = (Button) findViewById(R.id.btn2);

/*************************************************
* AnimationDrawable extends DrawableContainer
*************************************************/
// 1.取得ImageView
mTransitionIcon = (ImageView) findViewById(R.id.settings_transition_image);
// 2.为ImageView设置背景资源文件
mTransitionIcon.setBackgroundResource(R.drawable.transition_none);
// 3.把ImageView的背景赋给动画AnimationDrawable
frameAnimation = (AnimationDrawable) mTransitionIcon.getBackground();

mStackIcon = (ImageView) findViewById(R.id.transition_stack);
mStackIcon.setBackgroundResource(R.drawable.transition_stack);
stackAnimation = (AnimationDrawable) mStackIcon.getBackground();
stackThread = new Thread() {
@Override
public void run() {
stackAnimation.start();// 子线程中开始动画
}
};

btn1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
action = !action;// 主线程中控制动画启动与停止
if (action) {
frameAnimation.start(); // 启动（重启）动画
} else {
frameAnimation.stop(); // 停止动画
}
}
});

btn2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (stackThread.getState() == (Thread.State.NEW))
stackThread.start();// 放到子线程中开启动画
}// 先查询子线程状态再启动，避免Thread报错导致app退出
});

stopButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String s = "";// 用于显示状态
s = action ? "action! " + stackThread.getState().toString() :
"stop!" + stackThread.getState().toString();
tvState.setText(s);
}
});
}
}

Thread 类

状态一览：

/**
* A representation of a thread's state. A given thread may only be in one
* state at a time.
*/
public enum State {
/**
* The thread has been created, but has never been started.
*/
NEW,
/**
* The thread may be run.
*/
RUNNABLE,
/**
* The thread is blocked and waiting for a lock.
*/
BLOCKED,
/**
* The thread is waiting.
*/
WAITING,
/**
* The thread is waiting for a specified amount of time.
*/
TIMED_WAITING,
/**
* The thread has been terminated.
*/
TERMINATED
}

一个Button用于启动子线程，可以先判断子线程的状态，再决定是否启动