android 绘图--简单手写绘图后保存为图片（demo）

本demo是实现android绘图功能中，对图片简单手绘操作，然后保存编辑后的图片。其他画笔大小选择、画笔颜色选择、图片大小调整、图片效果调整、图片特效调整可以根据需要自行添加。
android 绘图对图片操作流程是：用特定的bitmap初始化画布，在此画布上绘图，用surfaceView 显示，然后保存绘图后的bitmap 。主代码如下：

package com.example.mypaintmrlin;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.nio.Buffer;import java.nio.ByteBuffer;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.Bitmap.CompressFormat;import android.graphics.Bitmap.Config;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Path;import android.graphics.PointF;import android.graphics.Rect;import android.graphics.drawable.BitmapDrawable;import android.os.Bundle;import android.os.Environment;import android.util.Log;import android.view.Menu;import android.view.MotionEvent;import android.view.SurfaceHolder;import android.view.SurfaceView;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class MainActivity extends Activity   {   private SurfaceView surfViewDraw=null;   private SurfaceHolder surHolder=null;   private Paint myPaint=null;   private Bitmap mBitmap=null; //create bitmap for to save the pixels   private Canvas mCanvas=null;   private Button btnSave=null;   private Button btnDraw=null;   private PointF mLeftSelectPoint;    private Path    mPath;   private Paint       mPaint;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);surfViewDraw=(SurfaceView)findViewById(R.id.surfVDraw);surHolder=surfViewDraw.getHolder();btnSave=(Button)findViewById(R.id.btnSave);btnDraw=(Button)findViewById(R.id.btnDraw);      mPaint = new Paint();          //set parameters of paint.        mPaint.setAntiAlias(true);        mPaint.setDither(true);        mPaint.setColor(0xFFFF0000);        mPaint.setStyle(Paint.Style.STROKE);        mPaint.setStrokeJoin(Paint.Join.ROUND);         mPaint.setStrokeCap(Paint.Cap.ROUND);        //set the width of stroke.        mPaint.setStrokeWidth(12);//setting my paint to drawmyPaint=new Paint();myPaint.setColor(Color.BLUE);myPaint.setStrokeWidth(1);mLeftSelectPoint = new PointF(0, 0);   mPath = new Path();btnSave.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubtry {saveBitmap(mBitmap);} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}}});  btnDraw.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubmyDraw();saveBuffer();}});surHolder.addCallback(new SurfaceHolder.Callback()   {         public void surfaceChanged(SurfaceHolder holder,int format,int width,int height)        {         if(mBitmap==null)        {                    mBitmap=Bitmap.createBitmap(width, height, Config.ARGB_8888);                    mCanvas=new Canvas(mBitmap);  //初始化画布                                        BitmapDrawable bitmapDraw=(BitmapDrawable)(getResources().getDrawable(R.drawable.ic_launcher));                     Bitmap bitmap = bitmapDraw.getBitmap();                                    if (bitmap != null) {         mCanvas.drawBitmap(bitmap, 0, 0, myPaint);         }                            }else        {                }                    Log.i("surfaceChange", "surface");        }public void surfaceCreated(SurfaceHolder holder) {}public void surfaceDestroyed(SurfaceHolder holder) {}     }); }public void myDraw(){ Canvas canvas=surHolder.lockCanvas( ); canvas.drawBitmap(mBitmap, 0, 0, null); surHolder.unlockCanvasAndPost(canvas); }private byte[] saveBuffer() {byte[] buffer = new byte[mBitmap.getRowBytes() * mBitmap.getHeight()];Buffer byteBuffer = ByteBuffer.wrap(buffer);mBitmap.copyPixelsToBuffer(byteBuffer);return buffer;}public void saveBitmap(Bitmap bitmap) throws FileNotFoundException{if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED)) {String sdcard = Environment.getExternalStorageDirectory().getPath().toString()+ "/external_sdcard";FileOutputStream fos = new FileOutputStream(sdcard+"lin.jpeg");bitmap.compress(CompressFormat.JPEG, 100, fos);}} private float mX, mY;     private static final float TOUCH_TOLERANCE = 4;     private void touch_start(float x, float y) {         mPath.reset();         mPath.moveTo(x, y);         mX = x;         mY = y;     }     private void touch_move(float x, float y) {         float dx = Math.abs(x - mX);         float dy = Math.abs(y - mY);         if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {             mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);             mX = x;             mY = y;         }         mCanvas.drawPath(mPath, mPaint);               myDraw();     }     private void touch_up() {         mPath.lineTo(mX, mY);         mPath.reset();     myDraw();saveBuffer();              }     @Override     public boolean onTouchEvent(MotionEvent event) {         float x = event.getX();         float y = event.getY();         switch (event.getAction()) {             case MotionEvent.ACTION_DOWN:                 touch_start(x, y);                  break;             case MotionEvent.ACTION_MOVE:                 touch_move(x, y);                  break;             case MotionEvent.ACTION_UP:                 touch_up();                  break;         }         return true;     }      @Overridepublic 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;}}

手绘效果图：

保存图片后：

源代码地址是：http://download.csdn.net/detail/linhuorongandroid/7116821 或进q群383012091 下载源码
附：android 源码大全网盘网址链接: http://pan.baidu.com/s/1o67CFZO 密码: 4jyk
PS：有任何问题可留言讨论，有不当之处多多指正。也可加q群：383012091 互相探讨。

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