在上传之前调整从图库或相机拍摄的图像的大小

我的网站中有一个表单，允许用户上传照片。我的 Android 应用程序使用 WebView 来允许用户访问该网站。单击上传按钮后，应用程序允许用户在图库中现有的图像之间进行选择，或者拍摄新照片并上传该图像。我为此使用的代码是

showAttachmentDialog 由 openFileChooser 调用

private void showAttachmentDialog(ValueCallback<Uri> uploadMsg) {
        this.mUploadMessage = uploadMsg;

        File imageStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "MyApp");
        // Create the storage directory if it does not exist
        if (! imageStorageDir.exists()){
            imageStorageDir.mkdirs();                  
        }
        File file = new File(imageStorageDir + File.separator + "IMG_" + String.valueOf(System.currentTimeMillis()) + ".jpg");


        this.imageUri= Uri.fromFile(file);


        final List<Intent> cameraIntents = new ArrayList<Intent>();
        final Intent captureIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
        final PackageManager packageManager = getPackageManager();
        final List<ResolveInfo> listCam = packageManager.queryIntentActivities(captureIntent, 0);
        for(ResolveInfo res : listCam) {
            final String packageName = res.activityInfo.packageName;
            final Intent intent = new Intent(captureIntent);
            intent.setComponent(new ComponentName(res.activityInfo.packageName, res.activityInfo.name));
            intent.setPackage(packageName);
            intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
            cameraIntents.add(intent);
        }


       // mUploadMessage = uploadMsg; 
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);  
        intent.addCategory(Intent.CATEGORY_OPENABLE);  
        intent.setType("image/*"); 
        Intent chooserIntent = Intent.createChooser(intent,"Image Chooser");
        chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, cameraIntents.toArray(new Parcelable[]{}));
        this.startActivityForResult(chooserIntent,  FILECHOOSER_RESULTCODE);
    }

我的 onActivityResult

protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
        if (requestCode == FILECHOOSER_RESULTCODE) {

            if (null == this.mUploadMessage) {
                return;
            }

            Uri result;
            if (resultCode != RESULT_OK) {
                result = null;
            } else {
                result = intent == null ? this.imageUri : intent.getData(); // retrieve from the private variable if the intent is null
            }

            this.mUploadMessage.onReceiveValue(result);
            this.mUploadMessage = null;



        }
    }

我希望能够在上传之前更改图像的大小，并且我希望在手机上完成此操作，而不是在网页中。完成此操作后，我还想从手机中删除调整大小的图像并保留原型。你能建议我一种方法来做到这一点吗？我在 SO 中展示了几种情况，建议创建位图并使用 createScaledBitmap 将其调整为所需的大小，但我不确定在我的情况下哪种是最好的方法。这应该在哪里进行？在我的 onActivityResult 中？ 提前致谢！

- - - - - - - - - - 编辑 - - - - - - - - - - -

私有文件imageStorageDir，文件；

我在我的主 Activity 中声明了这些，并在 onActivityResult 中添加了以下代码片段

String newPath=file.getAbsolutePath();
            Bitmap bMap= BitmapFactory.decodeFile(newPath);
            Bitmap out = Bitmap.createScaledBitmap(bMap, 150, 150, false);
            File resizedFile = new File(imageStorageDir, "resized.png");

            OutputStream fOut=null;
            try {
                fOut = new BufferedOutputStream(new FileOutputStream(resizedFile));
                out.compress(Bitmap.CompressFormat.PNG, 100, fOut);
                fOut.flush();
                fOut.close();
                bMap.recycle();
                out.recycle();

            } catch (Exception e) { // TODO

            }

现在，当使用相机拍照时，图像正在调整大小并上传，但是当我使用图库时，我收到 NullPointerException

05-23 10:12:50.354: E/BitmapFactory(1376): Unable to decode stream: java.io.FileNotFoundException: /storage/sdcard/Pictures/MyApp/IMG_1400854361171.jpg: open failed: ENOENT (No such file or directory)
05-23 10:12:50.364: D/AndroidRuntime(1376): Shutting down VM
05-23 10:12:50.414: W/dalvikvm(1376): threadid=1: thread exiting with uncaught exception (group=0x41465700)
05-23 10:12:50.494: E/AndroidRuntime(1376): FATAL EXCEPTION: main
05-23 10:12:50.494: E/AndroidRuntime(1376): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=Intent { dat=content://media/external/images/media/76 }} to activity {com.example.sinatra19/com.example.sinatra19.Sinatra22Activity}: java.lang.NullPointerException
05-23 10:12:50.494: E/AndroidRuntime(1376):     at android.app.ActivityThread.deliverResults(ActivityThread.java:3367)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at android.app.ActivityThread.handleSendResult(ActivityThread.java:3410)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at android.app.ActivityThread.access$1100(ActivityThread.java:141)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1304)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at android.os.Looper.loop(Looper.java:137)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at android.app.ActivityThread.main(ActivityThread.java:5103)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at java.lang.reflect.Method.invokeNative(Native Method)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at java.lang.reflect.Method.invoke(Method.java:525)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at dalvik.system.NativeStart.main(Native Method)
05-23 10:12:50.494: E/AndroidRuntime(1376): Caused by: java.lang.NullPointerException
05-23 10:12:50.494: E/AndroidRuntime(1376):     at android.graphics.Bitmap.createScaledBitmap(Bitmap.java:482)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at com.example.sinatra19.Sinatra22Activity.onActivityResult(Sinatra22Activity.java:158)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at android.app.Activity.dispatchActivityResult(Activity.java:5322)
05-23 10:12:50.494: E/AndroidRuntime(1376):     at android.app.ActivityThread.deliverResults(ActivityThread.java:3363)
05-23 10:12:50.494: E/AndroidRuntime(1376):     ... 11 more

-----------------------编辑2------------------------

这个片段

           String newPath=getRealPathFromURI(getApplicationContext(), result);


            Bitmap bMap= BitmapFactory.decodeFile(newPath);
            Bitmap out = Bitmap.createScaledBitmap(bMap, 150, 150, false);
            File resizedFile = new File(imageStorageDir, "resize.png");

            OutputStream fOut=null;
            try {
                fOut = new BufferedOutputStream(new FileOutputStream(resizedFile));
                out.compress(Bitmap.CompressFormat.PNG, 100, fOut);
                fOut.flush();
                fOut.close();
                bMap.recycle();
                out.recycle();

            } catch (Exception e) { // TODO

            }
this.mUploadMessage.onReceiveValue(Uri.fromFile(resizedFile));
        this.mUploadMessage = null;

calling

public String getRealPathFromURI(Context context, Uri contentUri) {
          Cursor cursor = null;
          try { 
            String[] proj = { MediaStore.Images.Media.DATA };
            cursor = context.getContentResolver().query(contentUri,  proj, null, null, null);
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
          } finally {
            if (cursor != null) {
              cursor.close();
            }
          }
        }

当用户从图库中选择照片时有效，并在从相机拍摄照片时崩溃。我需要将它们结合起来的方法

它所需要的只是一个 if 语句来检查用户选择的方法。文件是在 showAttachmentDialog 中创建的，因此私有 imageUri 始终具有该文件的 Uri。当用户选择相机选项时，结果也具有该值，而当他选择图库时，结果具有从图库中选择的图像的 Uri

if(result==this.imageUri){
            newPath=file.getAbsolutePath();}
            else{
            newPath=getRealPathFromURI(getApplicationContext(), result);}

最终代码是

@Override
    //Receives the results of startActivityFromResult
    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
        String newPath;
        if (requestCode == FILECHOOSER_RESULTCODE) {

            if (null == this.mUploadMessage) {
                return;
            }

            Uri result;
            if (resultCode != RESULT_OK) {
                result = null;
            } else {
                result = intent == null ? this.imageUri : intent.getData(); // retrieve from the private variable if the intent is null
                Log.e("result",result.toString() );
                Log.e("intent",this.imageUri.toString() );

            }

            if(result==this.imageUri){
            newPath=file.getAbsolutePath();}
            else{
            newPath=getRealPathFromURI(getApplicationContext(), result);}

            Bitmap bMap= BitmapFactory.decodeFile(newPath);
            Bitmap out = Bitmap.createScaledBitmap(bMap, 150, 150, false);
            File resizedFile = new File(imageStorageDir, "resize.png");

            OutputStream fOut=null;
            try {
                fOut = new BufferedOutputStream(new FileOutputStream(resizedFile));
                out.compress(Bitmap.CompressFormat.PNG, 100, fOut);
                fOut.flush();
                fOut.close();
                bMap.recycle();
                out.recycle();

            } catch (Exception e) { // TODO

            }


            this.mUploadMessage.onReceiveValue(Uri.fromFile(resizedFile));
            this.mUploadMessage = null;
            //resizedFile.delete();


        }
    }

    public String getRealPathFromURI(Context context, Uri contentUri) {
          Cursor cursor = null;
          try { 
            String[] proj = { MediaStore.Images.Media.DATA };
            cursor = context.getContentResolver().query(contentUri,  proj, null, null, null);
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
          } finally {
            if (cursor != null) {
              cursor.close();
            }
          }
        }