动画 -- 按钮 -- 左右晃动

import android.view.animation.Animation;
import android.view.animation.Transformation;

public class CustomAnim extends Animation {
    
    @Override   // 获取目标对象的宽高和容器的宽高。
    public void initialize(int width, int height, int parentWidth,
            int parentHeight) {
        
        super.initialize(width, height, parentWidth, parentHeight);
    }
    
    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
// interpolatedTime 从0到1，等动画执行完毕后就会变成1。t 变化对象。
//        System.out.println(interpolatedTime);
//        t.setAlpha(interpolatedTime);
        // interpolatedTime 补间动画
//        t.getMatrix().setTranslate(200*interpolatedTime, 200*interpolatedTime);
        // 左右摇摆动画（*20运动速度周期  *50表示左右摇摆幅度增大。）
        t.getMatrix().setTranslate((float) (Math.sin(interpolatedTime*20)*50), 0);
        
        super.applyTransformation(interpolatedTime, t);
    }
    
}

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

public class MainActivity extends Activity {

    private CustomAnim ca;

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

        ca = new CustomAnim();
        ca.setDuration(1000);

        findViewById(R.id.btnAnimMe).setOnClickListener(
                new View.OnClickListener() {
                    @Override
                    public void onClick(View arg0) {
                        arg0.startAnimation(ca);
                    }
                });
    }

    @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;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

}