【Animation】 使用handler和Runnable实现某一个控件的抖动效果

布局：

<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"
    android:background="#000000">

	<Button android:layout_width="wrap_content"
	    android:layout_height="wrap_content"
	    android:id="@+id/btn"
	    android:text="Hello!"/>
</LinearLayout>

代码：   使用handler的postDelayed方法每半秒钟发送一个消息来执行动画效果，同时在handler里面使动画平移的距离缩短，当距离为零时就通过handler的
removeCallbacks方法取消runnable正在执行的操作！
每一次点击按钮都重置一下动画的距离，并且开启runnable，执行操作！

package com.example.viewpager;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.TranslateAnimation;
import android.widget.Button;

public class MainActivity extends Activity {
	private Button btn;
	private int length;
	Handler handler = new Handler(){
		public void handleMessage(android.os.Message msg) {
			switch (msg.what) {
			case 0:
				length -= 2.5;
				TranslateAnimation animation = new TranslateAnimation(0,length , 0, 0);
				animation.setDuration(50);
				Log.i("----", length+"");
				btn.startAnimation(animation);
				if(length==0){
					handler.removeCallbacks(runnable);
				}
				break;

			default:
				break;
			}
		};
	};
	Runnable runnable = new Runnable() {
		public void run() {
			handler.sendEmptyMessage(0);
			handler.postDelayed(this, 80);
		}
	};
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		btn = (Button) findViewById(R.id.btn);
		btn.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				length = 30;
				handler.post(runnable);
			}
		});
	}
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

}