Android Pinch Zoom在模拟器中不起作用

Question

I am creating a simple application for android

ScaleGestureDetectore

for Image Which uses the pinch zoom

feature but it is not working on emulator Android Build Version 2.2

My Code for the Activity is As follows:

package com.example.androidgesturedemo;

import android.app.Activity;
import android.content.Context;
import android.graphics.Matrix;
import android.os.Bundle;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.widget.ImageView;

public class MainActivity extends Activity {

    private ImageView img;
    private Matrix matrix = new Matrix();
    private float scale = 1f;
    private ScaleGestureDetector SGD;

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

        img = (ImageView) findViewById(R.id.imageView1);
        SGD = new ScaleGestureDetector(this, new ScaleListener());
    }

    @Override
    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);
            img.setImageMatrix(matrix);

            return true;

        }
    }

    @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;
    }

}

Answer 1

You can test Multitouch in emulator with the help of a real device. Check here how to do that.