获取屏幕触点坐标并在屏幕截图上标记。

Touch_AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="cheng.touch" >

    <!-- SDCard中创建与删除文件权限 -->
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
    <!-- 向SDCard写入数据权限 -->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service android:name=".MyService" />
    </application>

</manifest>

Touch_MainActivity.java

package cheng.touch;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;


public class MainActivity extends ActionBarActivity {

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

        labelView = (TextView)findViewById(R.id.event_label);
        TextView touchView = (TextView)findViewById(R.id.touch_area);
        final TextView historyView = (TextView)findViewById(R.id.history_label);

        touchView.setOnTouchListener(new View.OnTouchListener(){
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                int action = event.getAction();
                switch (action) {
                    case (MotionEvent.ACTION_DOWN):
                        display("ACTION_DOWN", event);
                        break;
                    case (MotionEvent.ACTION_UP):
                        int historySize = processHistory(event);
                        historyView.setText("历史数据量：" + historySize);
                        display("ACTION_UP", event);
                        break;
                    case (MotionEvent.ACTION_MOVE):
                        display("ACTION_MOVE", event);
                        break;
                }
                return true;
            }
        });

        Button btn = (Button) findViewById(R.id.btn);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, MyService.class);
                startService(intent);
            }
        });
    }

    private void display(String eventType, MotionEvent event){
        int x = (int)event.getX();
        int y = (int)event.getY();
        float pressure = event.getPressure();
        float size = event.getSize();
        int RawX = (int)event.getRawX();
        int RawY = (int)event.getRawY();
        String msg = "";
        msg += "事件类型：" + eventType + "\n";
        msg += "相对坐标："+String.valueOf(x)+","+String.valueOf(y)+"\n";
        msg += "绝对坐标："+String.valueOf(RawX)+","+String.valueOf(RawY)+"\n";
        msg += "触点压力："+String.valueOf(pressure)+"， ";
        msg += "触点尺寸："+String.valueOf(size)+"\n";
        labelView.setText(msg);
    }
    private int processHistory(MotionEvent event)
    {
        int historySize = event.getHistorySize();
        for (int i = 0; i < historySize; i++) {
            long time = event.getHistoricalEventTime(i);
            float pressure = event.getHistoricalPressure(i);
            float x = event.getHistoricalX(i);
            float y = event.getHistoricalY(i);
            float size = event.getHistoricalSize(i);
            // 处理过程…
        }
        return historySize;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Touch_MyService.java

package cheng.touch;

import android.app.Service;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.IBinder;
import android.util.Log;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;

/**
 * Created by Cheng on 2015/4/13.
 */
public class MyService extends Service {
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Log.i("out", "Service onCreate");

        Bitmap bitmap = BitmapFactory.decodeFile("/sdcard/20150402_093240.png").copy(Bitmap.Config.ARGB_8888, true);

        Paint paint = new Paint();
        paint.setColor(Color.RED);// 设置红色

        Canvas canvas = new Canvas(bitmap);
        canvas.drawCircle(820, 720, 25, paint);
        canvas.save(Canvas.ALL_SAVE_FLAG );
        canvas.restore();

        File f = new File("/sdcard/0.png");
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(f);
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos);
            Log.i("out", "done");
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }
}