我有一张画布，我正在从媒体商店中显示一张图片作为背景，然后我正在画画。我想保存背景+已经绘制的内容但我只能保存背景，这对我来说毫无用处。我想知道我做错了什么。我基本上做了人们的建议here，但没有帮助。
这是我的代码： 编辑：这次我在这里上传了所有代码
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileChannel.MapMode;
import java.util.ArrayList;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.provider.MediaStore;
import android.view.Display;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Toast;
public class CanvasDrawingActivity extends Activity {
private ArrayList<Path> _graphics = new ArrayList<Path>();
private Paint mPaint;
public static final int GET_FROM_GALLERY = 1;
public static final int IMAGE_CAPTURE = 0;
public static final int SELECT_IMAGE_FROM_DEVICE = 1;
public Bitmap myBitmap;
public int isFirstTime = 0;
public DrawingPanel mPanel;
static int id = 1;
public Uri fileUri ;
@Override
public void onCreate(Bundle savedInstanceState) {
mPanel = new DrawingPanel(this);
mPanel.setId(findId());
super.onCreate(savedInstanceState);
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
//https://stackoverflow.com/questions/10937659/android-image-doesnt-save-using-native-camera-app-on-nexus-s
File f = new File(Environment.getExternalStorageDirectory().getPath(), String.format("%d.jpg", System.currentTimeMillis()));
fileUri= Uri.fromFile(f);
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
startActivityForResult(intent, IMAGE_CAPTURE);
setContentView(R.layout.main);
}
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.save:
savePicture();
return true;
case R.id.clear:
// startActivity(new Intent(this, Clear.class));
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public void savePicture(){
long now = System.currentTimeMillis();
OutputStream fos;
try {
fos = new FileOutputStream(String.format(Environment.getExternalStorageDirectory().getAbsolutePath()+"/edited_%d.jpg",now));
myBitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finish(); //close the activity.
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
//Detects request codes
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == IMAGE_CAPTURE && resultCode == RESULT_OK) {
Uri result;
result = fileUri;
//refresh storage
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory())));
try {
myBitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), result);
startDrawing();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
else if (resultCode == Activity.RESULT_CANCELED){
}
}
public void startDrawing(){
setContentView(mPanel);
mPaint = new Paint();
mPaint.setDither(true);
mPaint.setColor(0xFFFFFF00);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(3);
}
public int findId(){
View v = findViewById(id);
while (v != null){
v = findViewById(++id);
}
return id++;
}
class DrawingPanel extends SurfaceView implements SurfaceHolder.Callback {
private DrawingThread _thread;
private Path path;
public DrawingPanel(Context context) {
super(context);
setDrawingCacheEnabled(true);
getHolder().addCallback(this);
_thread = new DrawingThread(getHolder(), this);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
synchronized (_thread.getSurfaceHolder()) {
if(event.getAction() == MotionEvent.ACTION_DOWN){
path = new Path();
path.moveTo(event.getX(), event.getY());
path.lineTo(event.getX(), event.getY());
}else if(event.getAction() == MotionEvent.ACTION_MOVE){
path.lineTo(event.getX(), event.getY());
if(_graphics.size() > 0) {
_graphics.remove(_graphics.size() - 1);
}
_graphics.add(path);
}else if(event.getAction() == MotionEvent.ACTION_UP){
path.lineTo(event.getX(), event.getY());
_graphics.remove(_graphics.size() - 1);
_graphics.add(path);
}
return true;
}
}
//Source: http://thinkandroid.wordpress.com/2009/12/25/resizing-a-bitmap/
public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {
int width = bm.getWidth();
int height = bm.getHeight();
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// create a matrix for the manipulation
Matrix matrix = new Matrix();
// resize the bit map
matrix.postScale(scaleWidth, scaleHeight);
// recreate the new Bitmap
Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);
return resizedBitmap;
}
/**
* Converts a immutable bitmap to a mutable bitmap. This operation doesn't allocates
* more memory that there is already allocated.
*
* @param imgIn - Source image. It will be released, and should not be used more
* @return a copy of imgIn, but muttable.
*/
public Bitmap convertToMutable(Bitmap imgIn) {
try {
//this is the file going to use temporally to save the bytes.
// This file will not be a image, it will store the raw image data.
File file = new File(Environment.getExternalStorageDirectory() + File.separator + "temp.tmp");
//Open an RandomAccessFile
//Make sure you have added uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
//into AndroidManifest.xml file
RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw");
// get the width and height of the source bitmap.
int width = imgIn.getWidth();
int height = imgIn.getHeight();
Config type = imgIn.getConfig();
//Copy the byte to the file
//Assume source bitmap loaded using options.inPreferredConfig = Config.ARGB_8888;
FileChannel channel = randomAccessFile.getChannel();
MappedByteBuffer map = channel.map(MapMode.READ_WRITE, 0, imgIn.getRowBytes()*height);
imgIn.copyPixelsToBuffer(map);
//recycle the source bitmap, this will be no longer used.
imgIn.recycle();
System.gc();// try to force the bytes from the imgIn to be released
//Create a new bitmap to load the bitmap again. Probably the memory will be available.
imgIn = Bitmap.createBitmap(width, height, type);
map.position(0);
//load it back from temporary
imgIn.copyPixelsFromBuffer(map);
//close the temporary file and channel , then delete that also
channel.close();
randomAccessFile.close();
// delete the temp file
file.delete();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return imgIn;
}
@Override
public void onDraw(Canvas canvas) {
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth();
int height = display.getHeight();
myBitmap = getResizedBitmap(myBitmap, height, width);
if (isFirstTime<3){
myBitmap = convertToMutable(myBitmap);
canvas.drawBitmap(myBitmap, 0, 0, null);
isFirstTime++;
}
for (Path path : _graphics) {
//canvas.drawPoint(graphic.x, graphic.y, mPaint);
canvas.drawPath(path, mPaint);
}
}
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
_thread.setRunning(true);
_thread.start();
}
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
boolean retry = true;
_thread.setRunning(false);
while (retry) {
try {
_thread.join();
retry = false;
} catch (InterruptedException e) {
// we will try it again and again...
}
}
}
}
class DrawingThread extends Thread {
private SurfaceHolder _surfaceHolder;
private DrawingPanel _panel;
private boolean _run = false;
public DrawingThread(SurfaceHolder surfaceHolder, DrawingPanel panel) {
_surfaceHolder = surfaceHolder;
_panel = panel;
}
public void setRunning(boolean run) {
_run = run;
}
public SurfaceHolder getSurfaceHolder() {
return _surfaceHolder;
}
@Override
public void run() {
Canvas c;
while (_run) {
c = null;
try {
c = _surfaceHolder.lockCanvas(null);
synchronized (_surfaceHolder) {
if (c!=null)
_panel.onDraw(c);
}
} finally {
// do this in a finally so that if an exception is thrown
// during the above, we don't leave the Surface in an
// inconsistent state
if (c != null) {
_surfaceHolder.unlockCanvasAndPost(c);
}
}
}
}
}
}
这是main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:id="@+id/main_view">
</LinearLayout>
和menu.xml：
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
<item
android:id="@+id/save"
android:title="Save"/>
<item
android:id="@+id/clear"
android:title="Clear"/>
</menu>
任何帮助将不胜感激。谢谢！！
编辑：我得到了它的工作！在这里！@Override
public void onCreate(Bundle savedInstanceState) {
mPanel = new DrawingPanel(this);
mPanel.setId(findId());
super.onCreate(savedInstanceState);
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
//https://stackoverflow.com/questions/10937659/android-image-doesnt-save-using-native-camera-app-on-nexus-s
File f = new File(Environment.getExternalStorageDirectory().getPath(), String.format("%d.jpg", System.currentTimeMillis()));
fileUri= Uri.fromFile(f);
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
startActivityForResult(intent, IMAGE_CAPTURE);
setContentView(R.layout.main);
}
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.save:
savePicture();
return true;
case R.id.clear:
// startActivity(new Intent(this, Clear.class));
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public void savePicture(){
long now = System.currentTimeMillis();
OutputStream fos;
try {
//SAVE THIS ONE- replicate all paths
Canvas canvas = new Canvas(myBitmap);
for (Path path : _graphicsToSave)
{
canvas.drawPath(path, mPaint);
}
fos = new FileOutputStream(String.format(Environment.getExternalStorageDirectory().getAbsolutePath()+"/edited_%d.jpg",now));
myBitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finish(); //close the activity.
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
//Detects request codes
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == IMAGE_CAPTURE && resultCode == RESULT_OK) {
Uri result;
result = fileUri;
//refresh storage
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory())));
try {
myBitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), result);
//resize the picture to match the screen size
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth();
int height = display.getHeight();
myBitmap = getResizedBitmap(myBitmap, height, width);
startDrawing();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
else if (resultCode == Activity.RESULT_CANCELED){
}
}
//Source: http://thinkandroid.wordpress.com/2009/12/25/resizing-a-bitmap/
public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {
int width = bm.getWidth();
int height = bm.getHeight();
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// create a matrix for the manipulation
Matrix matrix = new Matrix();
// resize the bit map
matrix.postScale(scaleWidth, scaleHeight);
// recreate the new Bitmap
Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);
return resizedBitmap;
}
public void startDrawing(){
setContentView(mPanel);
mPaint = new Paint();
mPaint.setDither(true);
mPaint.setColor(0xFFFFFF00);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(3);
}
public int findId(){
View v = findViewById(id);
while (v != null){
v = findViewById(++id);
}
return id++;
}
class DrawingPanel extends SurfaceView implements SurfaceHolder.Callback {
private DrawingThread _thread;
private Path path;
public DrawingPanel(Context context) {
super(context);
setDrawingCacheEnabled(true);
getHolder().addCallback(this);
_thread = new DrawingThread(getHolder(), this);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
synchronized (_thread.getSurfaceHolder()) {
if(event.getAction() == MotionEvent.ACTION_DOWN){
path = new Path();
path.moveTo(event.getX(), event.getY());
path.lineTo(event.getX(), event.getY());
}else if(event.getAction() == MotionEvent.ACTION_MOVE){
path.lineTo(event.getX(), event.getY());
if(_graphics.size() > 0) {
_graphics.remove(_graphics.size() - 1);
}
_graphics.add(path);
}else if(event.getAction() == MotionEvent.ACTION_UP){
path.lineTo(event.getX(), event.getY());
_graphics.remove(_graphics.size() - 1);
_graphics.add(path);
_graphicsToSave.add(path);
}
return true;
}
}
@Override
public void onDraw(Canvas canvas) {
if (isFirstTime<3){
canvas.drawBitmap(myBitmap, 0, 0, null);
isFirstTime++;
}
for (Path path : _graphics) {
canvas.drawPath(path, mPaint);
}
}
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
_thread.setRunning(true);
_thread.start();
}
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
boolean retry = true;
_thread.setRunning(false);
while (retry) {
try {
_thread.join();
retry = false;
} catch (InterruptedException e) {
// we will try it again and again...
}
}
}
}
class DrawingThread extends Thread {
private SurfaceHolder _surfaceHolder;
private DrawingPanel _panel;
private boolean _run = false;
public DrawingThread(SurfaceHolder surfaceHolder, DrawingPanel panel) {
_surfaceHolder = surfaceHolder;
_panel = panel;
}
public void setRunning(boolean run) {
_run = run;
}
public SurfaceHolder getSurfaceHolder() {
return _surfaceHolder;
}
@Override
public void run() {
Canvas c;
while (_run) {
c = null;
try {
c = _surfaceHolder.lockCanvas(null);
synchronized (_surfaceHolder) {
if (c!=null)
_panel.onDraw(c);
}
} finally {
// do this in a finally so that if an exception is thrown
// during the above, we don't leave the Surface in an
// inconsistent state
if (c != null) {
_surfaceHolder.unlockCanvasAndPost(c);
}
}
}
}
}
}
答案 0 :(得分：0)
View mView;
mView.setDrawingCacheEnabled(true);
Bitmap newimg = mView.getDrawingCache();
请获取位图并尝试保存该位图。让我知道您需要更多帮助
答案 1 :(得分：0)
要画一些东西，你需要4个基本组件：一个用于容纳像素的位图，一个用于托管绘图调用的Canvas（写入位图），一个绘图基元（例如Rect，Path，text，Bitmap）和一个paint（描述绘图的颜色和样式）。
您当前粘贴的代码显示您正在保存myBitmap，但它不会显示您是否将myBitmap设置为绘图位图。可能不是完整的代码 我能想到这个问题的唯一原因是你没有使用你正在保存的位图。这是我为手指画创建的代码的link。您可以参考此代码以查看如何向画布提供位图以及如何在位图上绘制路径。