OnActivityResult活动错误：传递结果ResultInfo失败

Question

  @Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == PICK_IMAGE && resultCode == Activity.RESULT_OK) {
        android.net.Uri selectedImage = data.getData();
        String[] filePathColumn = {MediaStore.Images.Media.DATA};
        android.database.Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
        if (cursor == null)
            return;

        cursor.moveToFirst();

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

        File file = new File(filePath);

        RequestBody reqFile = RequestBody.create(MediaType.parse("image/*"), file);
        MultipartBody.Part body = MultipartBody.Part.createFormData("banner", file.getName(), reqFile);
        RequestBody name = RequestBody.create(MediaType.parse("text/plain"), "banner");

        Log.d("THIS", data.getData().getPath());

        retrofit2.Call<okhttp3.ResponseBody> req = service.postImage(body, name);
        req.enqueue(new Callback<ResponseBody>() {
            @Override
            public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {

            }

            @Override
            public void onFailure(Call<ResponseBody> call, Throwable t) {
                Log.e("FFF", t.getMessage());
                t.printStackTrace();
            }
        });
    }
}

错误堆栈：

Process: com.projectbox.uploadfile, PID: 17822
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=100, result=-1, data=Intent { dat=content://com.android.providers.media.documents/document/image:28362 flg=0x1 }} to activity {com.projectbox.uploadfile/com.projectbox.uploadfile.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:4220)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:4263)
at android.app.ActivityThread.-wrap20(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1601)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6349)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:893)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:783)
Caused by: java.lang.NullPointerException
at java.io.File.<init>(File.java:262)
at com.projectbox.uploadfile.MainActivity.onActivityResult(MainActivity.java:110)
at android.app.Activity.dispatchActivityResult(Activity.java:7025)
at android.app.ActivityThread.deliverResults(ActivityThread.java:4216)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:4263) 
at android.app.ActivityThread.-wrap20(ActivityThread.java)                                                                

Answer 1

文件路径似乎为空。您正在尝试使用纵隔存储data列从content:/URI获取文件。这可能起作用，也可能不起作用，正如Mark Murphy在《如何从URI消费内容》中所解释的那样。

获取内容的唯一可靠方法是使用ContentResolver.OpenInputStream()

然后，您可以在上载该流之前将其复制到文件中，也可以直接上载该流，如本OkHttp制作方法所述。