如何在onTouchEvent（）中检测单点触摸和多点触控

Question

我使用以下代码检测单指触摸和双指触摸。代码检测到双指触摸（count==2时）。

我也需要在单点触控上做一些动作。如果我用一根手指触摸屏幕，它就不会用于其他部分。我在这段代码中做错了什么？

@Override
public boolean onTouchEvent(MotionEvent event) {
    int action = event.getAction() & MotionEvent.ACTION_MASK;
    switch (action) {
        case MotionEvent.ACTION_POINTER_UP: {
            int count = event.getPointerCount();
            Log.v("count >>", count + "");
            if (count == 2) {
                // some action
            } else {
                Log.v("count not equal to 2", "not 2");
            }
            break;
        }
    }
    return true;
}

更新：

我在Activity中使用了此代码。我需要检测单点触控，多点触控。

在我的活动中，我有两张图片，一张在左边，另一张在右边。如果我点击图像，一些过程必须要做。如果我使用两根手指，我需要根据scale-factor重新调整图像大小。

这是我用过的代码：

已更新：

package com.pinch.detect;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.content.Context;
import android.content.ContextWrapper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.FloatMath;
import android.util.Log;
import android.view.Display;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.view.ScaleGestureDetector.SimpleOnScaleGestureListener;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

public class PinchDetectorActivity extends Activity {
    TextView textGestureAction;
    ImageView img1, img2;
    static Bitmap bm, bm1;

    boolean multiTouch = false;
    Context context;
    float scaleFactor = 0.0f;
    float lastscale;
    int scr_width, scr_height;
    Display display;
    private ScaleGestureDetector scaleGestureDetector;

    /** Called when the activity is first created. */

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        textGestureAction = (TextView) findViewById(R.id.GestureAction);
        img1 = (ImageView) findViewById(R.id.img_left);
        img2 = (ImageView) findViewById(R.id.img_right);
        display = getWindowManager().getDefaultDisplay();

        scr_width = display.getWidth();
        scr_height = display.getHeight();
        Log.v("width >>", Integer.toString(scr_width));
        Log.v("height >>", Integer.toString(scr_height));

        bm = BitmapFactory.decodeResource(this.getResources(),
                R.drawable.fiction1);
        img1.setImageBitmap(bm);
        bm1 = BitmapFactory.decodeResource(this.getResources(),
                R.drawable.fiction2);
        img2.setImageBitmap(bm1);
        img1.setScaleType(ImageView.ScaleType.FIT_START);
        img2.setScaleType(ImageView.ScaleType.FIT_END);

        scaleGestureDetector = new ScaleGestureDetector(this,
                new MySimpleOnScaleGestureListener());



        img1.setOnTouchListener(new OnTouchListener(){

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                // TODO Auto-generated method stub
                return false;
            }

        });
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {

        scaleGestureDetector.onTouchEvent(event);
        int index = event.getActionIndex();
        Log.v("Index value ",index+"");
        int action = event.getAction();

        if (index == 1) {
            multiTouch = true;
            System.out.println("mutli1");
        } else if (multiTouch == false) {
            System.out.println("single1");
            img1.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {
                    Log.v("clicked image1","img1>>>");
                }
            });
            img2.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) { // TODO Auto-generated method
                    Log.v("clicked image2","img2>>>");
                }
            });
        }

         else if (action == MotionEvent.ACTION_MOVE && multiTouch) {
            System.out.println("mutli2");


            if (scaleFactor > 1) {

                Bitmap resizedbitmap = Bitmap.createScaledBitmap(bm,
                        scr_width / 2, scr_height, true);
                img1.setImageBitmap(resizedbitmap);
                Bitmap resizedbitmap1 = Bitmap.createScaledBitmap(bm1,
                        scr_width / 2, scr_height, true);
                img2.setImageBitmap(resizedbitmap1);
                Log.v("width >>", Integer.toString(scr_width));
                Log.v("height >>", Integer.toString(scr_height));

            } else if(scaleFactor<1){

                Log.v("width >>", Integer.toString(scr_width));
                Log.v("height >>", Integer.toString(scr_height));
                if (scr_width >= 640) {
                    Bitmap resizedbitmap = Bitmap.createScaledBitmap(bm,
                            scr_height + 90, scr_height, true);

                    img1.setImageBitmap(resizedbitmap);

                    Bitmap resizedbitmap1 = Bitmap.createScaledBitmap(bm1,
                            scr_height + 90, scr_height, true);

                    img2.setImageBitmap(resizedbitmap1);
                } else {
                    Bitmap resizedbitmap = Bitmap.createScaledBitmap(bm,
                            scr_height, scr_height + 30, true);

                    img1.setImageBitmap(resizedbitmap);

                    Bitmap resizedbitmap1 = Bitmap.createScaledBitmap(bm1,
                            scr_height, scr_height + 30, true);

                    img2.setImageBitmap(resizedbitmap1);
                }

            }



        } else if (action == MotionEvent.ACTION_MOVE && !multiTouch)
        {
            System.out.println("single2");
        }

        return super.onTouchEvent(event);

    }

    public class MySimpleOnScaleGestureListener extends
            SimpleOnScaleGestureListener {

        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            // TODO Auto-generated method stub

            scaleFactor = detector.getScaleFactor();

            Log.v("scaleFactor >>>", scaleFactor + "");

            return true;
        }
    }

}

我的main.xml是

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:id="@+id/pinchlay" >


    <ImageView
        android:id="@+id/img_left"
        android:layout_width="320dp"
        android:layout_height="fill_parent"
        />

    <ImageView
        android:id="@+id/img_right"
        android:layout_width="320dp"
        android:layout_height="fill_parent"
        android:layout_alignParentRight="true"
        />

</RelativeLayout>

Answer 1

如果我理解正确，单击不会导致ACTION_POINTER_UP，而是ACTION_UP。这就是它没有检测到单指的原因。看这篇文章以供参考： https://stackoverflow.com/a/4269592/1084813

Answer 2

正如之前的海报建议的那样，单个触摸指针有单独的事件，而不是动作。 motionEvents序列如下：

1. ACTION_DOWN
2. （ACTION_MOVE）
3. ACTION_POINTER_DOWN
4. （ACTION_MOVE）
5. （ACTION_POINTER_ID_SHIFT）
6. （重复下来的手指）
7. ACTION_POINTER_UP
8. （重复直到只留下一根手指）
9. ACTION_UP

Here's是理解多点触控事件的一个很好的资源，但抓住它们的想法和最简单的方法是使用switch语句。我使用TouchImageView找到了here。它的作用是允许缩放和平移，如果您只是单击它，它会执行单击，因此您可以将该处理代码添加到OnClickListener()或只是将其插入第125行。

Answer 3

以下是检测点并以不同颜色绘制每个点的代码get competition example here

public class custom_view extends View {



private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);

public int cu = 0;



final int MAX_NUMBER_OF_POINT = 10;

float[] x = new float[MAX_NUMBER_OF_POINT];

float[] y = new float[MAX_NUMBER_OF_POINT];

boolean[] touching = new boolean[MAX_NUMBER_OF_POINT];



public custom_view(Context context, AttributeSet attrs, int defStyle) {

    super(context, attrs, defStyle);

    init();

}

public custom_view(Context context, AttributeSet attrs) {

    super(context, attrs);

    init();

}



public custom_view(Context context) {

    super(context);

    init();

}

void init() {

    paint.setStyle(Paint.Style.STROKE);

    paint.setStrokeWidth(40);

}

@Override

protected void onDraw(Canvas canvas) {

    for (int i = 0; i < MAX_NUMBER_OF_POINT; i++) {

        if (touching[i]) {

            switch (i) {

            case 1:

                paint.setColor(Color.BLUE);

                break;

            case 2:

                paint.setColor(Color.RED);

                break;

            case 3:

                paint.setColor(Color.CYAN);

                break;

            case 4:

                paint.setColor(Color.GREEN);

                break;

            case 5:

                paint.setColor(Color.YELLOW);

                break;

            case 6:

                paint.setColor(Color.MAGENTA);

                break;

            case 7:

                paint.setColor(Color.DKGRAY);

                break;

            case 8:

                paint.setColor(Color.LTGRAY);

                break;

            case 9:

                paint.setColor(Color.GREEN);

                break;

            case 10:

                paint.setColor(Color.BLACK);



                break;

                }

            canvas.drawCircle(x[i], y[i], 70f, paint);

        }

    }

}

@Override

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

    setMeasuredDimension(MeasureSpec.getSize(widthMeasureSpec),

            MeasureSpec.getSize(heightMeasureSpec));

}

@Override

public boolean onTouchEvent(MotionEvent event) {

    int action = (event.getAction() & MotionEvent.ACTION_MASK);

    int pointCount = event.getPointerCount();

    for (int i = 0; i < pointCount; i++) {

        int id = event.getPointerId(i);



        if (id < MAX_NUMBER_OF_POINT) {

            x[id] = (int) event.getX(i);

            y[id] = (int) event.getY(i);



            if ((action == MotionEvent.ACTION_DOWN)

                    || (action == MotionEvent.ACTION_POINTER_DOWN)

                    || (action == MotionEvent.ACTION_MOVE)) {

                touching[id] = true;

            } else {

                touching[id] = false;

                }

        }

    }

    invalidate();

    return true;

}

}

Answer 4

您是否尝试使用OnDoubleTapListener？

找到这个tutorial也很有帮助，展示了如何检测单击和双击。

Answer 5

单次触摸我无法重现count == 2。单手触摸对我来说是1。 尝试在真实设备上调试您的代码并查看您实际拥有的内容。

将event.getPointerId（i）与event.getPointerCount（）一起使用，看看这些实际触摸点是什么。

Answer 6

您检查了ACTION_DOWN，但同时您还需要检查ACTION_POINTER_DOWN，这更清楚了。试试吧

 @Override
    public boolean onTouchEvent(MotionEvent event) {    
         scaleGestureDetector.onTouchEvent(event);

         int action = event.getAction();

         if( (action == MotionEvent.ACTION_DOWN) && (action != MotionEvent.ACTION_POINTER_DOWN))
             // Single touch
        else if ( action == MotionEvent.ACTION_POINTER_DOWN)
            //multi touch

        return true;
}   

被修改

boolean multiTouch=false;
 @Override
public boolean onTouchEvent(MotionEvent event) {
    // TODO Auto-generated method stub

    int index= event.getActionIndex();
    int action = event.getAction();

    if( index ==1)
    {
        multiTouch=true;
        System.out.println("mutli");
    }
    else if (multiTouch==false)
        System.out.println("single");
    //else if (action== MotionEvent.ACTION_POINTER_1_UP)
    //  multiTouch=false;
    else if (action== MotionEvent.ACTION_MOVE && multiTouch)
        System.out.println("mutli");
    else if (action== MotionEvent.ACTION_MOVE && !multiTouch)
        System.out.println("single");

        return super.onTouchEvent(event);
}

编辑：

 package com.pinch.detect;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.content.Context;
import android.content.ContextWrapper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.FloatMath;
import android.util.Log;
import android.view.Display;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.view.ScaleGestureDetector.SimpleOnScaleGestureListener;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

public class PinchDetectorActivity extends Activity {
    TextView textGestureAction;
    ImageView img1, img2;
    static Bitmap bm, bm1;

boolean multiTouch = false;
Context context;
float scaleFactor = 0.0f;
float lastscale;
int scr_width, scr_height;
Display display;
private ScaleGestureDetector scaleGestureDetector;

/** Called when the activity is first created. */

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    textGestureAction = (TextView) findViewById(R.id.GestureAction);
    img1 = (ImageView) findViewById(R.id.img_left);
    img2 = (ImageView) findViewById(R.id.img_right);
    display = getWindowManager().getDefaultDisplay();

    scr_width = display.getWidth();
    scr_height = display.getHeight();
    Log.v("width >>", Integer.toString(scr_width));
    Log.v("height >>", Integer.toString(scr_height));

    bm = BitmapFactory.decodeResource(this.getResources(),
            R.drawable.fiction1);
    img1.setImageBitmap(bm);
    bm1 = BitmapFactory.decodeResource(this.getResources(),
            R.drawable.fiction2);
    img2.setImageBitmap(bm1);
    img1.setScaleType(ImageView.ScaleType.FIT_START);
    img2.setScaleType(ImageView.ScaleType.FIT_END);

    scaleGestureDetector = new ScaleGestureDetector(this,
            new MySimpleOnScaleGestureListener());



    img1.setOnTouchListener(new OnTouchListener(){

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            // TODO Auto-generated method stub
            system.out.println("Image 1 touched");
            return false;
        }

    });



img2.setOnTouchListener(new OnTouchListener(){

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            // TODO Auto-generated method stub
            system.out.println("Image 2 touched");
            return false;
        }

    });
}

@Override
public boolean onTouchEvent(MotionEvent event) {

    scaleGestureDetector.onTouchEvent(event);
    int index = event.getActionIndex();
    Log.v("Index value ",index+"");
    int action = event.getAction();

    if (index == 1) {
        multiTouch = true;
        System.out.println("mutli1");
    } else if (multiTouch == false) {
        System.out.println("single1");
        img1.onTouch(view, event);

    }

     else if (action == MotionEvent.ACTION_MOVE && multiTouch) {
        System.out.println("mutli2");
         img2.onTouch(view, event);

        if (scaleFactor > 1) {

            Bitmap resizedbitmap = Bitmap.createScaledBitmap(bm,
                    scr_width / 2, scr_height, true);
            img1.setImageBitmap(resizedbitmap);
            Bitmap resizedbitmap1 = Bitmap.createScaledBitmap(bm1,
                    scr_width / 2, scr_height, true);
            img2.setImageBitmap(resizedbitmap1);
            Log.v("width >>", Integer.toString(scr_width));
            Log.v("height >>", Integer.toString(scr_height));

        } else if(scaleFactor<1){

            Log.v("width >>", Integer.toString(scr_width));
            Log.v("height >>", Integer.toString(scr_height));
            if (scr_width >= 640) {
                Bitmap resizedbitmap = Bitmap.createScaledBitmap(bm,
                        scr_height + 90, scr_height, true);

                img1.setImageBitmap(resizedbitmap);

                Bitmap resizedbitmap1 = Bitmap.createScaledBitmap(bm1,
                        scr_height + 90, scr_height, true);

                img2.setImageBitmap(resizedbitmap1);
            } else {
                Bitmap resizedbitmap = Bitmap.createScaledBitmap(bm,
                        scr_height, scr_height + 30, true);

                img1.setImageBitmap(resizedbitmap);

                Bitmap resizedbitmap1 = Bitmap.createScaledBitmap(bm1,
                        scr_height, scr_height + 30, true);

                img2.setImageBitmap(resizedbitmap1);
            }

        }



    } else if (action == MotionEvent.ACTION_MOVE && !multiTouch)
    {
        System.out.println("single2");
    }

    return super.onTouchEvent(event);

}

public class MySimpleOnScaleGestureListener extends
        SimpleOnScaleGestureListener {

    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        // TODO Auto-generated method stub

        scaleFactor = detector.getScaleFactor();

        Log.v("scaleFactor >>>", scaleFactor + "");

        return true;
    }
}

}

最新：

if (index == 1) {
        multiTouch = true;
        img2.onTouch(view, event);
    System.out.println("mutli1");
} else if (multiTouch == false) {
    System.out.println("single1");
    img1.onTouch(view, event);

}

 else if (action == MotionEvent.ACTION_MOVE && multiTouch) {
    System.out.println("mutli2");

Answer 7

您必须使用MultiTouch的PointerID用户。见 Complete Example

private View.OnTouchListener OnTouchListener = new View.OnTouchListener() {
        public boolean onTouch(View view, MotionEvent event) { 
            int pointerIndex = ((event.getAction() & MotionEvent.ACTION_POINTER_ID_MASK) >> MotionEvent.ACTION_POINTER_ID_SHIFT);
            int action = event.getAction() & MotionEvent.ACTION_MASK;
            int pointerId = event.getPointerId(pointerIndex);
            Log.i("", "Pointer ID = " + pointerId);
            switch (action) {
            case MotionEvent.ACTION_POINTER_UP: {

                break;
            }
            }
            return true;
        }
    };