java.lang.NullPointerException：尝试调用虚方法'java.lang.String android.net.Uri.getScheme（）' [英] java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()'

问题描述

我正在尝试从图库和相机上传图像到服务器。当我选择图库中的图像上传到服务器时它的工作可能。但是当我选择相机捕获的图像上传到服务器时崩溃并显示错误。

I am Trying To upload image to server from gallery and camera.When i Choose image from gallery to upload to server its Work Perfactly.But when i Select camera captured Image for upload to server Its Crash And Showing the error.

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference

OnActivityResult。

At OnActivityResult.

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == PICK_IMAGE && resultCode == RESULT_OK
                && null != data) {
            Uri selectedImage = data.getData();
            String[] filePathColumn = { MediaStore.Images.Media.DATA };

            Cursor cursor = getContentResolver().query(selectedImage,
                    filePathColumn, null, null, null);
            cursor.moveToFirst();

            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String picturePath = cursor.getString(columnIndex);
            cursor.close();

            decodeFile(picturePath);
            new ImageUploadTask().execute();
        }else {

            Toast.makeText(getApplicationContext(), "User Canceled",
                    Toast.LENGTH_LONG).show();
        }
    }

我在onActivityResult上的这一行收到错误

i got the error on this line in onActivityResult

 Cursor cursor = getContentResolver().query(selectedImage,
                        filePathColumn, null, null, null);
                cursor.moveToFirst();

按钮点击时用于打开相机的方法。

The method i used for open camera on button click.

  loadimage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {


                AlertDialog.Builder builder = new AlertDialog.Builder(Add_Info.this);
                builder.setMessage("Select Image From")
                        .setCancelable(true)
                        .setPositiveButton("Camera", new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {

                                Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                                startActivityForResult(intent, CAMERA_REQUEST);
                                mImageCaptureUri = Uri.fromFile(new File(Environment
                                        .getExternalStorageDirectory(), "tmp_avatar_"
                                        + String.valueOf(System.currentTimeMillis())
                                        + ".jpg"));
                            }
                        })
                        .setNegativeButton("Gallery", new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                Intent i = new Intent(
                                        Intent.ACTION_PICK,
                                        android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);

                                startActivityForResult(i, RESULT_LOAD_IMAGE);

                            }
                        });
                AlertDialog alert = builder.create();
                alert.show();


            }
        });

帮我解决这个问题。我不知道如果我使用的话怎么会出现这个错误已经在我以前的项目中。

Help Me solve this problem.I don't know How t get this error even after i used is already in my Previous PROJECT.

提前感谢

推荐答案

我在使用Camera api和onActivityResult的Intent时遇到了同样的问题，最后我发现它取决于你的Android设备版本，在Android M（Marshmallow - 6.0-6.0.1）中，onActivityResult意图如下：

I had same issue when working with Camera api and Intent of onActivityResult, finally I found out it depends on your android device version, in Android M (Marshmallow - 6.0–6.0.1 ) onActivityResult intent is like below :

requestCode : 230 resultCode : -1 intent :Intent{dat=file:///storage/emulated/0/Pictures/Rahnama/IMG_20160508_121332_1519065    564.jpg typ=image/jpeg } RESULT_OK : -1

以及低于Marshmallow的Android版本：

and for android versions lower than Marshmallow:

requestCode : 230 resultCode : -1 intent : Intent { dat=content://media/external/images/media/309 (has extras) } RESULT_OK : -1

我认为你必须检查Android版本onActivityResult和for andr oid版本Marshmallow从Uri和Intent中的路径获取直接文件：

I think you must check android version onActivityResult and the for android versions Marshmallow to get direct file from path in the Uri and Intent:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (Build.VERSION.SDK_INT == Build.VERSION_CODES.M){
            final Uri data = intent.getData();
            final File file = new File(data.getPath());
            // now you can upload your image file
    }else{
           // in android version lower than M your method must work
    }

我希望它对你有用。

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