Question

我正在尝试通过打开一个文件来加载来自SD卡/设备内存的图像，该文件将代表该路径的字符串作为参数：

File imagePathFile = new File(savedImapthPathwayOnPause);
        try {

            final int IMAGE_MAX_SIZE = 3000;
            FileInputStream streamIn = new FileInputStream(imagePathFile);

            // important to reduce size of image before it is loaded into memory
            // and then resized, otherwise will
            // get out of memory error

            // Decode image size and setInJBounds = true to avoid auto memory
            // allocation for large image
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(streamIn, null, o);
            streamIn.close();

            //by setting m.pow(scale, 3.85) we get a org image of 2500:1400 beofre loaded and when loaded we get 426:240, no need fro resize method call here
            int scale = 1;
            while ((o.outWidth * o.outHeight) * (1 / Math.pow(scale, 3.73)) > IMAGE_MAX_SIZE) {
                scale++;
            }

            // get orginal width of image before loaded into memory
            Log.d("VIEW DIVE", "scale = " + scale + ", orig-width: " + o.outWidth
                    + "  orig-height: " + o.outHeight);
            //Toast.makeText(getApplicationContext(), "Orginal Image size from DB: width: "+ o.outWidth + "/height: " + o.outHeight , Toast.LENGTH_LONG).show();

            Bitmap b = null;
            streamIn = new FileInputStream(imagePathFile);
            if (scale > 1) {
                scale--;
                // scale to max possible inSampleSize that still yields an image
                // larger than target, inSampleSize loads the image into memor
                // by a factor of its integer value
                o = new BitmapFactory.Options();
                o.inSampleSize = scale;
                // Decode bitmap with inSampleSize set
                o.inJustDecodeBounds = false;

                b = BitmapFactory.decodeStream(streamIn, null, o);
                //makeToast("Image after sacling and now loading: width: "+ o.outWidth + "/height: " + o.outHeight );
                //resizedImage = reSizeImage(b); this is blowing uo and alreadt samll image from
                //org size 2500:1400 to 73:44, then blown back up in resize does not look good

                streamIn.close();
                //b.recycle();
                System.gc();

但我一直得到以下例外：

java.io.FileNotFoundException: /: open failed: EISDIR (Is a directory)
    at libcore.io.IoBridge.open(IoBridge.java:416)  at
java.io.FileInputStream.<init>(FileInputStream.java:78)     at
com.mooney.diveapp.LogDive.setImageViewFromSavedInstance(LogDive.java:198)
    at com.mooney.diveapp.LogDive.onCreate(LogDive.java:134)    at
android.app.Activity.performCreate(Activity.java:5255)      at
android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097)

编辑：如何设置图像路径字符串（在asycnh内部类中完成）：

// check if external storage is available to write
            Bitmap imageToSave = params[0];// get image

            final String state = Environment.getExternalStorageState();
            if (Environment.MEDIA_MOUNTED.equals(state)) {
                // media available
                canSaveToExternalSD = true;
                // use a random number to append to image file name until use
                // diveNumber according to log entry on
                Random diveNum = new Random();
                File sdCard = Environment.getExternalStorageDirectory();
                final File directory = new File(sdCard.getAbsolutePath()
                        + File.separator + diveAlbum);
                final File theFile = new File(directory, "image"
                        + diveNum.nextInt(5000) + ".png");
                directory.getParentFile().mkdirs();

                if (!directory.mkdirs()) {
                    Log.d(TAG, "Directory not created!!!!");
                }

                try {
                    FileOutputStream out = new FileOutputStream(theFile);
                    imageToSave.compress(Bitmap.CompressFormat.PNG, 90, out);
                    out.flush();
                    out.close();

//assign path to a string
savedImagePath = theFile.getAbsolutePath();

稍后在代码中，saveImagePath被分配给savedImapthPathwayOnPause。

编辑：稍后在代码中展开。因此，当用户通过调用活动B中的Goggle Maps或Facebookpost活动导航表格活动A时，我将字符串savedImagePath保存在onSavedINstance状态。

然后，当用户返回活动A时，我在创建时返回savedIMagePathway，并将其传递给上面发布的文件imagePathFile = new File（savedImagePathwayOnPause）上面发布的方法。

此时savedImagePathwayOnPause的值为：/ storage_emulated/0/dive_photos/image2588.png

但是，有时此值返回空（到其初始化状态=“”）。这似乎是随机的......因为有些时候有效而不是其他......

@Override
        protected void onSaveInstanceState(Bundle outState) {

            //if onPause called on activity when user selects maps or FB, we lose value of global varibles like 
            //saveIMageBPath and photoBitMap but keep all view values (Edittexts)
            //so we must save our global values here and call them back on onRestoreInstance state and assign to IMageButton

            super.onSaveInstanceState(outState);
            uiHelper.onSaveInstanceState(outState);


           outState.putString("savedImapthPathwayOnSaveInstance", savedImagePath);
        }

并在onCreate（）中：

if (savedInstanceState != null) {
            // Restore value of members from saved state
           // mCurrentScore = savedInstanceState.getInt(STATE_SCORE); 
            this.savedImapthPathwayOnPause = savedInstanceState.getString("savedImapthPathwayOnSaveInstance");
            Toast.makeText(getApplicationContext(), "on returning the image path is : " + savedImapthPathwayOnPause, Toast.LENGTH_SHORT).show();
            //no we ust get the bitmap form the image path and return to IMageView
            Log.d("MYTAG", "on returning the image path is : " + savedImapthPathwayOnPause);

            if(!savedImapthPathwayOnPause.isEmpty())
            setImageViewFromSavedInstance(savedImapthPathwayOnPause);
            Log.d("MYTAG", "on returning the image path not found:==  " + savedImapthPathwayOnPause);
        }

Answer 1

由于@Paf建议问题是图像路径是在同步类中生成的，所以如果在生成路径之前调用了File open，那么我将一个空字符串传递给File构造函数。

为了避免这种情况，我通过禁用在Pre-Exceute上执行此操作的按钮禁用了对创建文件的任何调用，并在生成String文件路径之后在Aynsch内部类的onPostExceute方法中再次启用它们。

由于

FileNotFoundException从SD卡路径加载图像

1 个答案: