Android捏缩放在模拟器中不起作用

Question

我正在为 android 创建一个简单的应用程序

比例手势检测器

对于使用捏缩放

的图像

功能，但它不适用于模拟器 Android Build Version 2.2

我的活动代码如下：

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

您可以借助真机在模拟器中测试多点触控。检查here 怎么做。