Question

我有一个使用相机拍摄图像的应用程序。

     String[] galleryPermissions = {Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE};

    if (EasyPermissions.hasPermissions(this, galleryPermissions)){
    //Camera
    if (index == 0) {
        Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        // Ensure that there's a camera activity to handle the intent
        if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
            // Create the File where the photo should go
            File photoFile = null;
            try {
                photoFile = createImageFile();
            } catch (IOException ex) {            
            Toast.makeText(getApplicationContext(),ex.getMessage(),Toast.LENGTH_LONG).show();
            }
            // Continue only if the File was successfully created
            if (photoFile != null) {

                Uri photoURI = null;

                // N is for Nougat Api 24 Android 7
                if (Build.VERSION_CODES.N <= android.os.Build.VERSION.SDK_INT) {
                    // FileProvider required for Android 7.  Sending a file URI throws exception.


                    photoURI = FileProvider.getUriForFile(this,
                            BuildConfig.APPLICATION_ID + ".provider",
                            photoFile);


                    Log.v("highbuild",photoURI.toString());

                } else {
                    // For older devices:
                    // Samsung Galaxy Tab 7" 2 (Samsung GT-P3113 Android 4.2.2, API 17)
                    // Samsung S3
                    photoURI = Uri.fromFile(photoFile);
                    Log.v("lowbuild",photoURI.toString());
                }
                imageuriduplicate = photoURI;
                takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
                startActivityForResult(takePictureIntent, 0);
            }
            else{
                Log.v("file", "photo file is null");
                Toast.makeText(getApplicationContext(),"Photo file is null", Toast.LENGTH_LONG).show();
            }
        }

    }

    //Gallery
    else if (index == 1) {

        Intent pickPhoto = new Intent(Intent.ACTION_PICK,
                MediaStore.Images.Media.INTERNAL_CONTENT_URI);
        pickPhoto.setType("image/*");
        startActivityForResult(pickPhoto, 1);//one can be replaced with any action code
    }
}

else {
    EasyPermissions.requestPermissions(this, "Access for storage",
            101, galleryPermissions);
}

我的创建文件图像方法是这样的

   private File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = "AndroidUpload" + timeStamp + "_";
    File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
    if(!storageDir.exists()){

        boolean s = new File(storageDir.getPath()).mkdirs();

        if(!s){
            Log.v("not", "not created");
        }
        else{
            Log.v("cr","directory created");
        }
    }
    else{
        Log.v("directory", "directory exists");
    }

    File image = File.createTempFile(
            imageFileName,  /* prefix */
            ".png",         /* suffix */
            storageDir      /* directory */
    );

    // Save a file: path for use with ACTION_VIEW intents
    mCurrentPhotoPath = image.getAbsolutePath();
    return image;
}

然后我将路径保存到arraylist并访问它。

但是当我尝试访问这样的文件时

                Uri imageuri = Uri.parse(receipts.get(i).imageURI);
                File file = new File(imageuri.getPath());
            if(file.exists()){
                Log.v("exists","file exists");
            }
            else{
                Log.v("no","file doesnt exist");
            }

我得到的文件不存在错误。

我已经提供了所有必要的权限，但我仍然遇到此错误。怎么解决这个问题？

Answer 1

确保storageDir存在。如果没有使用

创建目录

new File(path_to_dir).mkdirs();

android中不存在文件？

1 个答案: