android实现加载动画对话框

public class LoadingProgressDialog extends ProgressDialog {
 
 private AnimationDrawable mAnimation;
 private Context mContext;
 private ImageView mImageView;
 private String mLoadingTitle;
 private TextView mLoadingTv;
 private int mResid;
 
 public LoadingProgressDialog(Context context, String content, int id) {
 super(context);
 this.mContext = context;
 this.mLoadingTitle = content;
 this.mResid = id;
 setCanceledOnTouchOutside(true);
 }
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 initView();
 initData();
 }
 
 private void initData() {
 
 mImageView.setBackgroundResource(mResid);
 mAnimation = (AnimationDrawable) mImageView.getBackground();
 mImageView.post(new Runnable() {
 @Override
 public void run() {
 mAnimation.start();
 }
 });
 mLoadingTv.setText(mLoadingTitle);
 
 }
 
 public void setContent(String str) {
 mLoadingTv.setText(str);
 }
 
 private void initView() {
 setContentView(R.layout.progress_dialog);
 mLoadingTv = (TextView) findViewById(R.id.loadingTv);
 mImageView = (ImageView) findViewById(R.id.loadingIv);
 }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:gravity="center"
 android:layout_gravity="center"
 android:orientation="vertical">
 
 <ImageView
  android:id="@+id/loadingIv"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content" />
 
 <TextView
  android:id="@+id/loadingTv"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:textColor="#ffffff"
  android:textSize="20sp" />
 
</LinearLayout>

<?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/loading_01"
  android:duration="100" />
 <item
  android:drawable="@drawable/loading_02"
  android:duration="100" />
 <item
  android:drawable="@drawable/loading_03"
  android:duration="100" />
 <item
  android:drawable="@drawable/loading_04"
  android:duration="100" />
</animation-list>

LoadingProgressDialog dialog =new LoadingProgressDialog(MainActivity.this, "正在加载中...",R.anim.frame);
//打开
dialog.show();
//隐藏
dialog.dismiss();