Question

我使用过ScaleGestureDetector。我使用了这段代码，但它在片段中不起作用，也没有显示任何错误请有人帮我这个提前但是当我在活动中使用相同的代码时，它完美地运作

public class Fragment2 extends Fragment {
ImageView imgZoom;
Matrix matrix = new Matrix();
float scale = 1f;
ScaleGestureDetector SGD;

// Keep all Images in array
         Integer[] mThumbIds = {
                R.drawable. car1, R.drawable.car2,
                R.drawable.car3, R.drawable.car4,
                R.drawable.car5,R.drawable.car6,
                R.drawable.car7,R.drawable.car8,
                R.drawable.car9,R.drawable.car10,
                R.drawable.car11,R.drawable.car12
                };



   @Override
   public View onCreateView(LayoutInflater inflater,
      ViewGroup container, Bundle savedInstanceState) {
       /**
           * Inflate the layout for this fragment
           */
       View view = inflater.inflate(R.layout.fragment2,container,false);

      //Sets the title of the Bar
      final ActionBar bar = getActivity().getActionBar();
      bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
      bar.setTitle("Pinch to zoom");

      //Recives the value of position sent from Fragment1
      int pos=getArguments().getInt("position");

      Button btnBack=(Button)view.findViewById(R.id.btnBack);

      imgZoom=(ImageView)view.findViewById(R.id.imageViewZoom);
      imgZoom.setImageResource(mThumbIds[pos]);
      SGD = new ScaleGestureDetector(view.getContext(),new ScaleListener());

      btnBack.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
             Intent mainScreen = new Intent(getActivity(), MainActivity.class);
             startActivity(mainScreen);
        }
    });

      return view;
   }
   public boolean onTouchEvent(MotionEvent ev) {
      SGD.onTouchEvent(ev);
      return true;
   }

   private class ScaleListener extends ScaleGestureDetector.
   SimpleOnScaleGestureListener {
   @Override
   public boolean onScale(ScaleGestureDetector detector) {
      scale *= detector.getScaleFactor();
      scale = Math.max(0.1f, Math.min(scale, 5.0f));
      matrix.setScale(scale, scale);
      imgZoom.setImageMatrix(matrix);
      return true;
   }
}

}

Answer 1

试试这个。它适合我。

view.setOnTouchListener(new OnTouchListener() {
        @Override
        public boolean onTouch(View view, MotionEvent motionEvent) {
            SGD.onTouchEvent(motionEvent);
            return true;
        }
    });

如何在Fragment中实现Zoom Pinch Gesture

1 个答案: