Android Dev:从存储在SD卡上的临时文件创建位图,设置ImageView,然后在本地存储

时间:2013-03-19 03:47:33

标签: android bitmap android-sdcard fileinputstream

因为刚刚从android.media.action.IMAGE_CAPTURE获取数据的质量问题,我显然需要调用该活动,保存一个本地临时文件,然后我可以创建一个Bitmap。此位图将被裁剪为正方形,设置为ImageView,然后存储在本地;但是,我遇到了一些问题。所有东西(现在不包括裁剪)都可以设置图像(它返回一个空白图像)并在内部存储它,此时它会崩溃。我尝试使用文件管理器在SD卡上找到该文件,但文件夹甚至没有显示,所以我不知道该文件是否真的被创建。我有什么想法我做错了吗?代码:

private static final String TAG = "AddEdit";
private final static String FOLDER_NAME = "com.ex.beerlog/Image/";
private Uri selectedImageUri = null;
private final static int CAPTURE_IMAGE_CALLBACK = 1;


switch (arg0.getId()) {
            case R.id.imageView1:

                File photo = null;
                Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");

                if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED)) {
                    photo = new File(android.os.Environment.getExternalStorageDirectory(), FOLDER_NAME + File.separator
                            + "temp.png");
                    Log.w(TAG, "*******Photo path set from Enviro*********");
                } else {
                    photo = new File(getCacheDir(), FOLDER_NAME + File.separator + "temp.png");
                    Log.w(TAG, "*******photo set from cache*********");
                }
                if (photo != null) {
                    Log.w(TAG, "*******Photo is not null*********");
                    intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
                    intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);
                    selectedImageUri = Uri.fromFile(photo);
                    Log.w(TAG, "*******from imageUri=" + selectedImageUri + "*********");
                    startActivityForResult(intent, CAPTURE_IMAGE_CALLBACK);
                }
 break;



  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);

        switch (requestCode) {
            case CAPTURE_IMAGE_CALLBACK:
                if (resultCode == RESULT_OK) {
                    String path = selectedImageUri.toString();
                    Log.w(TAG, "*****path set =" + path + "******");
                    BitmapFactory.Options options = new BitmapFactory.Options();
                    Log.w(TAG, "*****Bimapfactory options set******");
                    options.inPreferredConfig = Bitmap.Config.ARGB_8888;
                    Log.w(TAG, "****Options defined********");
                    bmp = BitmapFactory.decodeFile(path, options);
                    Log.w(TAG, "*****Bmp is set ==> crop******");

                    brewPhoto.setImageBitmap(bmp);
                    Log.w(TAG, "******************Image is set to ButtonImage**********************");
                    // Store image
                    FileOutputStream fos;
                    Log.w(TAG, "********FileOutPutStream created*************");
                    try {
                        fos = openFileOutput(cDate, Context.MODE_PRIVATE);
                        Log.w(TAG, "********FileOutPutStream defined*************");
                        bmp.compress(Bitmap.CompressFormat.PNG, 100, fos);
                        Log.w(TAG, "********bitmap compressed*************");
                        fos.close();
                        Log.w(TAG, "*****FOS closed**********");
                    } catch (FileNotFoundException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
                break;
        }
    }

这是我收到的错误日志:

03-18 21:24:50.325: W/AddEdit(8208): *****path set =file:///storage/sdcard0/com.ex.beerlog/Image/temp.png******
03-18 21:24:50.325: W/AddEdit(8208): *****Bimapfactory options set******
03-18 21:24:50.325: W/AddEdit(8208): ****Options defined********
03-18 21:24:50.325: I/System.out(8208): Not a DRM File, opening notmally
03-18 21:24:50.325: W/AddEdit(8208): *****Bmp is set ==> crop******
03-18 21:24:50.325: W/AddEdit(8208): ******************Image is set to ButtonImage**********************
03-18 21:24:50.325: W/AddEdit(8208): ********FileOutPutStream created*************
03-18 21:24:50.325: W/AddEdit(8208): ********FileOutPutStream defined*************
03-18 21:24:50.335: W/dalvikvm(8208): threadid=1: thread exiting with uncaught exception (group=0x41314438)
03-18 21:24:50.335: E/AndroidRuntime(8208): FATAL EXCEPTION: main
03-18 21:24:50.335: E/AndroidRuntime(8208): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=null} to activity {com.ex.beerlog/com.ex.beerlog.AddEdit}: java.lang.NullPointerException
03-18 21:24:50.335: E/AndroidRuntime(8208):     at android.app.ActivityThread.deliverResults(ActivityThread.java:3183)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at android.app.ActivityThread.handleSendResult(ActivityThread.java:3226)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at android.app.ActivityThread.access$1200(ActivityThread.java:139)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1272)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at android.os.Handler.dispatchMessage(Handler.java:99)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at android.os.Looper.loop(Looper.java:137)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at android.app.ActivityThread.main(ActivityThread.java:4918)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at java.lang.reflect.Method.invokeNative(Native Method)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at java.lang.reflect.Method.invoke(Method.java:511)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1004)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:771)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at dalvik.system.NativeStart.main(Native Method)
03-18 21:24:50.335: E/AndroidRuntime(8208): Caused by: java.lang.NullPointerException
03-18 21:24:50.335: E/AndroidRuntime(8208):     at com.ex.beerlog.AddEdit.onActivityResult(AddEdit.java:329)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at android.app.Activity.dispatchActivityResult(Activity.java:5232)
03-18 21:24:50.335: E/AndroidRuntime(8208):     at android.app.ActivityThread.deliverResults(ActivityThread.java:3179)
03-18 21:24:50.335: E/AndroidRuntime(8208):     ... 11 more

因此,您可以看到fileInputSteam已创建,但在尝试存储图像时崩溃。我已删除此段代码,并且设置为ImageView的图像为空白(透明)。所以我假设它崩溃了,因为实际上什么都没有?我试图在Manifest中设置权限以允许访问SD卡。还要注意我正在我的Galaxy sIII上测试,启用了调试器。我也没有保护SD卡并拔掉手机以确保SD卡可用,但每次都是相同的结果。

再次感谢。你们这里的所有人都非常了不起!

1 个答案:

答案 0 :(得分:0)

好的,所以我想出了我的问题,希望这会帮助我这样的人解决这个问题。

如果你想从你的CAMERA意图中收集高质量的信息,你必须(从我发现的)将图像保存到SD卡。我的应用程序返回一个空白(我认为是透明的)图像,因为图像从未存在过。 您必须创建文件路径,它不是自动过程。

我通过设置静态路径来完成此操作,并在该位置创建了一个temp.png:

File photo = null;
                File path = new File("storage/sdcard0/Android/data/com.ex.beerlog/");
                String pathstring = path.toString();
                if (!path.exists()) {
                    path.mkdirs();
                    Log.w(TAG, "*******Photo Directory Created*********");
                } else { // do nothing
                }

最后,我仍想在内部存储我拍摄的照片,但图像尺寸会导致内存不足(OOM)异常。因此,为了解决这个问题,我创建了一个矩阵,将图像缩小到350px宽(实际上是我的应用程序所需的最大尺寸图像)。 **你会注意到一个“matrix.postrotate(90)”,这是因为我的照片会以其他方式返回。

 private Bitmap cropImage(Bitmap bmp2) {
        // TODO Auto-generated method stub
        int width = bmp2.getWidth();
        int height = bmp2.getHeight();
        float scale = (float) 350/bmp.getHeight();

        Log.w(TAG, "*********Image Wt=" + width + ", Ht=" + height + " scale"+scale+"*********");

        Matrix matrix = new Matrix();
        matrix.postScale(scale, scale);
        matrix.postRotate(90);

        // recreate the new Bitmap
        Bitmap resizedBitmap = Bitmap.createBitmap(bmp2, 0, 0, width, height, matrix, true);
        int bmpHtWidth = resizedBitmap.getWidth();
        int bmpHeight = resizedBitmap.getHeight();
        int bmpTop = (bmpHeight - bmpHtWidth) / 2;
        Log.w(TAG, "*********resizedImage HtWt=" + bmpHtWidth + ", Ht=" + bmpHeight + ", top=" + bmpTop + "*********");

        return resizedBitmap;
        }

这些基本上回答了我的上述问题。希望它也可以帮助其他人!

编辑::哦,当我在活动之间得到一张小照片时,我遇到了一个问题,导致了一个OOM。为了解决这个问题,我在活动关闭之前使用了Bitmap.recycle()函数并转移到下一个活动。这将尝试在活动之间释放一些记忆。