多点触控介绍以及程序代码

实现onTouch(View view, MotionEventevent)的方法，就可以获取触屏的感应事件了。

在该事件中，有两个参数可以用来获取对触摸的控制，这两个参数分别为：MotionEvent.getAction()和MotionEvent.ACTION_MASK，前者用于对单点触控进行操作，后者用于对多点触控进行操作，相应地，我们可以通过AndroidDevelopers’Reference看到，对于单点触控，我们由MotionEvent.getAction()可以得到以下几种事件：ACTION_DOWN、ACTION_UP，而对于多点触控，由MotionEvent.ACTION_MASK，我们可以得到：ACTION_POINTER_DOWN、ACTION_POINTER_UP，都是MotionEvent中的常量，可以直接调用。而有些常量则是单点和多点共用的，如：ACTION_MOVE，因此在按下时，我们必须标记单点与多点触控的区别。

package map2.intel;

import android.app.Activity;

import android.app.AlertDialog;

import android.content.DialogInterface;

import android.content.res.Resources;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.Matrix;

import android.graphics.PointF;

import android.os.Bundle;

import android.util.DisplayMetrics;

import android.util.FloatMath;

import android.util.Log;

import android.view.LayoutInflater;

import android.view.Menu;

import android.view.MenuItem;

import android.view.MotionEvent;

import android.view.View;

import android.view.View.OnTouchListener;

import android.widget.EditText;

import android.widget.ImageView;

import android.widget.RelativeLayout;

import android.widget.TextView;

import android.widget.Toast;

public class Map2Activity extends Activity {

   

TextView view;

ImageView imgView;

ImageView imgStarView;

private EditText nameEditText;

private EditText passwordEditText;

RelativeLayout reLayout;

DisplayMetrics dm = new DisplayMetrics();

final static float scale =Resources.getSystem().getDisplayMetrics().density;

int mapWidth;

int mapHight;

int phoneMapWidth;

int phoneMapHight;

int leftTopLocationX;

int leftTopLocationY;

int phoneMapLocationX;

int phoneMapLocationY;

private static final int NONE = 0;

private static final int DRAG = 1;

private static final int ZOOM = 2;

private int mode = NONE;

private float oldDist;

private Matrix matrix = new Matrix();

private Matrix savedMatrix = new Matrix();

private PointF start = new PointF();

private PointF mid = new PointF();

float scale2;

private static final int OPTION_Setting = 0;

    @Override

    public voidonCreate(Bundle savedInstanceState) {

       super.onCreate(savedInstanceState);

       setContentView(R.layout.fl);

      this.getWindowManager().getDefaultDisplay().getMetrics(dm);

       

       

       view = (TextView)findViewById(R.id.textView1);

      imgView=(ImageView)findViewById(R.id.imageView1);

      imgStarView=(ImageView)findViewById(R.id.imageView2);

      reLayout=(RelativeLayout)findViewById(R.id.relativeLayout1);

       reLayout.setVisibility(View.INVISIBLE);

       

  Bitmap nineFmap =BitmapFactory.decodeResource(getResources(), R.drawable.rn);

 

  mapWidth=nineFmap.getWidth();

  mapHight=nineFmap.getHeight();

    

    phoneMapWidth=dm.widthPixels;

    phoneMapHight=dipToPixel(170);

  Toast.makeText(getApplicationContext(),String.valueOf(dm.widthPixels)+String.valueOf(mapHight),

     Toast.LENGTH_SHORT).show();

    leftTopLocationX=16;

    leftTopLocationY=16;

     

     

    imgView.setOnTouchListener(newOnTouchListener()

{

@Override

public boolean onTouch(View v, MotionEvent event)

{

float[] values = new float[9]; 

ImageView view = (ImageView) v;

switch (event.getAction() &MotionEvent.ACTION_MASK)

{

case MotionEvent.ACTION_DOWN:

savedMatrix.set(matrix);

start.set(event.getX(), event.getY());

mode = DRAG;

values = new float[9]; 

matrix.getValues(values); 

break;

case MotionEvent.ACTION_UP:

mode = NONE;

break;

case MotionEvent.ACTION_POINTER_UP:

phoneMapLocationX=(int)(phoneMapLocationX*scale2);

phoneMapLocationY=(int)(phoneMapLocationY*scale2);

mode = NONE;

// if()

break;

case MotionEvent.ACTION_POINTER_DOWN:

oldDist = spacing(event);

if (oldDist > 10f)

{

savedMatrix.set(matrix);

midPoint(mid, event);

mode = ZOOM;

values = new float[9]; 

matrix.getValues(values); 

}

break;

case MotionEvent.ACTION_MOVE:

if (mode == DRAG)

{

System.out.println("View移动");

matrix.set(savedMatrix);

matrix.postTranslate(event.getX() - start.x,

event.getY() - start.y);

values = new float[9]; 

matrix.getValues(values); 

imgStarView.setPadding((int)(values[2]+phoneMapLocationX),(int)(values[5]+phoneMapLocationY),0,0);

}

else if (mode == ZOOM)

{

float newDist = spacing(event);

if (newDist > 10f)

{

matrix.set(savedMatrix);

scale2 = newDist /oldDist;//scale<1,reduce;scale>1,magnify

matrix.postScale(scale2, scale2, mid.x, mid.y);

matrix.getValues(values); 

imgStarView.setPadding((int)(values[2]+phoneMapLocationX*scale2),(int)(values[5]+phoneMapLocationY*scale2),0,0);

}

}

break;

}

view.setImageMatrix(matrix);

return true;

}

private float spacing(MotionEvent event)

{

float x = event.getX(0) - event.getX(1);

float y = event.getY(0) - event.getY(1);

return FloatMath.sqrt(x * x + y * y);

}

private void midPoint(PointF point, MotionEvent event)

{

float x = event.getX(0) + event.getX(1);

float y = event.getY(0) + event.getY(1);

point.set(x / 2, y / 2);

}

});

       

    }

    

public static int dipToPixel(int dip)

{

     return (int) (dip * scale + 0.5f);

}

    public booleanonCreateOptionsMenu(Menu menu)

    {

   menu.add(0,OPTION_Setting, 0, "Location");

    return true;

    }

    public booleanonOptionsItemSelected(MenuItem item)

    {

    LayoutInflater factory =LayoutInflater.from(this);

    final View textEntryView= factory.inflate(R.layout.second, null);

    int itemId =item.getItemId();

     switch(itemId){

      caseOPTION_Setting: 

           finalAlertDialog.Builder alert = newAlertDialog.Builder(Map2Activity.this);

          alert.setTitle("alert Title");

          alert.setView(textEntryView);

          alert.setPositiveButton("Ok",

                 new DialogInterface.OnClickListener() {

                     publicvoid onClick(DialogInterface dialog,int whichButton) {

                    reLayout.setVisibility(View.VISIBLE);

                    passwordEditText =(EditText)textEntryView.findViewById(R.id.password_edit); 

                    nameEditText =(EditText)textEntryView.findViewById(R.id.username_edit);

                     phoneMapLocationX=phoneMapWidth*Integer.valueOf(nameEditText.getText().toString())/mapWidth+leftTopLocationX;

                      phoneMapLocationY=phoneMapHight*Integer.valueOf(passwordEditText.getText().toString())/mapHight+leftTopLocationY;

                    imgStarView.setPadding((int)(phoneMapLocationX),(int)(phoneMapLocationY),0, 0);

                     }

                 });

          

          alert.setNegativeButton("Cancel",

                 new DialogInterface.OnClickListener() {

                     publicvoid onClick(DialogInterface dialog,

                           int whichButton) {

                     }

                 });  

          alert.show(); 

     }

     return true;

    }

    

    

    

}