Android自定义Animation实现View摇摆效果

<?xml version="1.0" encoding="utf-8"?><LinearLayout  xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:background="#ffffff"  android:gravity="center"  android:orientation="vertical">  <!--图片-->  <ImageView    android:id="@+id/iv_dial"    android:layout_width="200dp"    android:layout_height="200dp"    android:src="@drawable/img"/>  <!--控制按钮-->  <LinearLayout    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:layout_gravity="bottom"    android:gravity="center"    android:orientation="horizontal">    <Button      android:id="@+id/btn_start"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:text="开始"/>    <Button      android:id="@+id/btn_end"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:text="结束"/>  </LinearLayout></LinearLayout>

/** * 主界面 * Created by zhuwentao on 2016-08-08. */public class MainActivity extends AppCompatActivity implements View.OnClickListener{  /** 表盘图片 */  private ImageView mDialIv;  /** 开始按钮 */  private Button mStartBtn;  /** 结束按钮 */  private Button mEndBtn;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    initUI();    initListener();  }  /**   * 初始化UI   */  private void initUI() {    mDialIv = (ImageView) findViewById(R.id.iv_dial);    mStartBtn = (Button) findViewById(R.id.btn_start);    mEndBtn = (Button) findViewById(R.id.btn_end);  }  /**   * 初始化监听   */  private void initListener() {    mStartBtn.setOnClickListener(this);    mEndBtn.setOnClickListener(this);  }  @Override  public void onClick(View v) {    switch (v.getId()) {      case R.id.btn_start:        showAnimation();        break;      case R.id.btn_end:        mDialIv.clearAnimation();        break;    }  }  /**   * 设置动画   */  private void showAnimation() {    // 获取自定义动画实例    CustomRotateAnim rotateAnim = CustomRotateAnim.getCustomRotateAnim();    // 一次动画执行1秒    rotateAnim.setDuration(1000);    // 设置为循环播放    rotateAnim.setRepeatCount(-1);    // 设置为匀速    rotateAnim.setInterpolator(new LinearInterpolator());    // 开始播放动画    mDialIv.startAnimation(rotateAnim);  }}

/** * 左右摇摆动画 * Created by zhuwentao on 2016-08-08. */public class CustomRotateAnim extends Animation {  /** 控件宽 */  private int mWidth;  /** 控件高 */  private int mHeight;  /** 实例 */  private static CustomRotateAnim rotateAnim;  /**   * 获取动画实例   * @return 实例   */  public static CustomRotateAnim getCustomRotateAnim() {    if (null == rotateAnim) {      rotateAnim = new CustomRotateAnim();    }    return rotateAnim;  }  @Override  public void initialize(int width, int height, int parentWidth, int parentHeight) {    this.mWidth = width;    this.mHeight = height;    super.initialize(width, height, parentWidth, parentHeight);  }  @Override  protected void applyTransformation(float interpolatedTime, Transformation t) {    // 左右摇摆    t.getMatrix().setRotate((float)(Math.sin(interpolatedTime*Math.PI*2)*50), mWidth/2, mHeight/2);    super.applyTransformation(interpolatedTime, t);  }}