android实现点击图片全屏展示效果

public class MainActivity extends AppCompatActivity {
 private ImageView imageView;
 private Dialog dialog;
 private ImageView image;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 init();
 
 //小图的点击事件（弹出大图）
 imageView.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View v) {
  dialog.show();
  }
 });
 
 }
 
 private void init() {
 imageView = (ImageView) findViewById(R.id.image);
 
 //展示在dialog上面的大图
 dialog = new Dialog(MainActivity.this,R.style.FullActivity);
 
 WindowManager.LayoutParams attributes = getWindow().getAttributes();
 attributes.width = WindowManager.LayoutParams.MATCH_PARENT;
 attributes.height = WindowManager.LayoutParams.MATCH_PARENT;
 dialog.getWindow().setAttributes(attributes);
 
 image = getImageView();
 dialog.setContentView(image);
 
 //大图的点击事件（点击让他消失）
 image.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View v) {
  dialog.dismiss();
  }
 });
 
 }
 
 //动态的ImageView
 private ImageView getImageView(){
 ImageView imageView = new ImageView(this);
 
 //宽高
 imageView.setLayoutParams(new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
 
 //imageView设置图片
 @SuppressLint("ResourceType") InputStream is = getResources().openRawResource(R.drawable.lala);
 
 Drawable drawable = BitmapDrawable.createFromStream(is, null);
 imageView.setImageDrawable(drawable);
 
 return imageView;
 }
}