android - 从 android Api 23 及以上版本将图像上传到服务器

Question

我希望我的应用程序从 Android 的图库中选择一张图像并将其上传到服务器上。该代码在 API lenel 22(即 Lollipop )上运行良好。但在 API 级别 23 上失败并出现 NullPointerException。 API 23之后有什么变化吗？如果是的话，那是什么。

这是我使用的代码。

 public void onClickAddProfileImage(View v) {
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setType("image/*");
        startActivityForResult(intent, PICK_PROFILE_PHOTO);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == PICK_PROFILE_PHOTO && resultCode == Activity.RESULT_OK) {
            uploader.setVisibility(View.VISIBLE);
            Uri selectedImage = data.getData();
            String[] projection = {MediaStore.Images.Media.DATA};
            CursorLoader loader = new CursorLoader(this, selectedImage, projection, null, null, null);
            Cursor cursor = loader.loadInBackground();
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            Uri imageUri = Uri.parse(cursor.getString(column_index));
            cursor.close();
            Intent in = new Intent();
            UploadFile file_upload = new UploadFile(this, in);
            file_upload.execute();
        }
    }

以及我在线获取的错误日志

Uri imageUri = Uri.parse(cursor.getString(column_index));

是

     Process: com.webkul.taskapp, PID: 2648  java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=Intent { dat=content://com.android.providers.media.documents/document/image:205520 flg=0x1 }} to activity {com.webkul.taskapp/com.webkul.taskapp.BaseActivity}: java.lang.NullPointerException: uriString
        at android.app.ActivityThread.deliverResults(ActivityThread.java:3720)
        at android.app.ActivityThread.handleSendResult(ActivityThread.java:3763)
        at android.app.ActivityThread.-wrap16(ActivityThread.java)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1403)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:148)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
     Caused by: java.lang.NullPointerException: uriString
        at android.net.Uri$StringUri.<init>(Uri.java:475)
        at android.net.Uri$StringUri.<init>(Uri.java)
        at android.net.Uri.parse(Uri.java:437)
        at com.webkul.taskapp.BaseActivity.onActivityResult(BaseActivity.java:535)
        at android.app.Activity.dispatchActivityResult(Activity.java:6442)
        at android.app.ActivityThread.deliverResults(ActivityThread.java:3716)
        at android.app.ActivityThread.handleSendResult(ActivityThread.java:3763) 
        at android.app.ActivityThread.-wrap16(ActivityThread.java) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1403) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:148) 
        at android.app.ActivityThread.main(ActivityThread.java:5443) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)     
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)

请任何人提出解决该问题的建议。

Answer 1

使用大量代码，您试图从...一个 Uri 构造一个 Uri。

data.geData() 已经是 Uri，您可以使用它打开 InputStream 来上传文件。