上传图片错误：尝试在空对象引用上调用虚拟方法’java.lang.String android.net.Uri.getLastPathSegment()’

概述我有“用相机捕获图像”的问题,并将其存储到Firebase中.我认为该代码是正确的,因为它可以与“从图库中选择图像”一起使用.捕获完图像后,该应用程序停止了,并且没有存储在数据库中.我认为这对于androidM和N是个问题.我只是看到其他类似的问题,但它们对我不起作用.我为此寻求帮助,

我有“用相机捕获图像”的问题,并将其存储到Firebase中.我认为该代码是正确的,因为它可以与“从图库中选择图像”一起使用.捕获完图像后,该应用程序停止了,并且没有存储在数据库中.我认为这对于android M和N是个问题.我只是看到其他类似的问题,但它们对我不起作用.我为此寻求帮助,因为我不知道解决方案.谢谢. logcat中也存在错误.

 @OverrIDeprotected voID onActivityResult(int requestCode, int resultCode, Intent data) {    super.onActivityResult(requestCode, resultCode, data);    if (requestCode == CAMERA_REQUEST_CODE && resultCode == RESulT_OK){        mPregresDialog.setMessage("Uploading...");        mPregresDialog.show();        Uri uri = data.getData();        StorageReference filepath = mStorage.child("Photo").child(uri.getLastPathSegment());        filepath.putfile(uri).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {            @OverrIDe            public voID onSuccess(UploadTask.TaskSnapshot taskSnapshot) {                mPregresDialog.dismiss();                Toast.makeText(MainActivity.this, "Upload Done", Toast.LENGTH_LONG).show();            }        });    }}

日志猫：

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method ‘java.lang.String androID.net.Uri.getLastPathSegment()’ on a null object reference

解决方法:

对于您的问题,我有一个答案,因为几天前我做了同样的事情.问题在于您的Uri无法获得应有的图像,因此您需要为捕获的图像创建自己的Uri.

您需要转到androID文档：https://developer.android.com/training/camera/photobasics.html#TaskPhotoView

对于您的应用,您还可以将以下代码复制并粘贴到您的主要活动中：

String mCurrentPhotopath;private file createImagefile() throws IOException {// Create an image file nameString timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new     Date());String imagefilename = "JPEG_" + timeStamp + "_";file storageDir = getExternalfilesDir(Environment.DIRECTORY_PICTURES);file image = file.createTempfile(        imagefilename,  /* prefix */        ".jpg",         /* suffix */        storageDir      /* directory */);// Save a file: path for use with ACTION_VIEW intentsmCurrentPhotopath = image.getabsolutePath();return image;}private voID dispatchTakePictureIntent() {Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);// Ensure that there's a camera activity to handle the intentif (takePictureIntent.resolveActivity(getPackageManager()) != null) {    // Create the file where the photo should go    file photofile = null;    try {        photofile = createImagefile();    } catch (IOException ex) {        // Error occurred while creating the file...    }    // Continue only if the file was successfully created    if (photofile != null) {        Uri photoURI = fileProvIDer.getUriForfile(this,                "com.example.androID.fileprovIDer",                photofile);        takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);        startActivityForResult(takePictureIntent, CAMERA_REQUEST_CODE);    }}}@OverrIDeprotected voID onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentVIEw(R.layout.activity_main);storage = FirebaseStorage.getInstance().getReference();b_gallery = (button) findVIEwByID(R.ID.b_gallery);b_capture = (button) findVIEwByID(R.ID.b_capture);iv_image = (ImageVIEw) findVIEwByID(R.ID.iv_image);progressDialog = new ProgressDialog(this);b_capture.setonClickListener(new VIEw.OnClickListener() {    @OverrIDe    public voID onClick(VIEw vIEw) {        //Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);        dispatchTakePictureIntent();    }});}@OverrIDeprotected voID onActivityResult(int requestCode, int resultCode, Intent data) {super.onActivityResult(requestCode, resultCode, data);if(requestCode == CAMERA_REQUEST_CODE && resultCode == RESulT_OK){    progressDialog.setMessage("Uploading...");    progressDialog.show();    Uri uri = data.getData();    StorageReference filepath =     storage.child("Photos").child(uri.getLastPathSegment());    filepath.putfile(photoURI).addOnSuccessListener(new    OnSuccessListener<UploadTask.TaskSnapshot>() {        @OverrIDe        public voID onSuccess(UploadTask.TaskSnapshot taskSnapshot) {            Toast.makeText(MainActivity.this, "Upload Successful!",    Toast.LENGTH_SHORT).show();            progressDialog.dismiss();        }    }).addOnFailureListener(new OnFailureListener() {        @OverrIDe        public voID onFailure(@NonNull Exception e) {            Toast.makeText(MainActivity.this, "Upload Failed!", Toast.LENGTH_SHORT).show();        }    });    }}}

并确保您遵循文档并在AndroIDManifest.xml中添加了提供程序：

<provIDer    androID:name="androID.support.v4.content.fileProvIDer"    androID:authoritIEs="com.example.androID.fileprovIDer"    androID:exported="false"    androID:grantUriPermissions="true">    <Meta-data        androID:name="androID.support.file_PROVIDER_PATHS"        androID:resource="@xml/file_paths"></Meta-data></provIDer>

还有res / xml / file_paths.xml(您只需在“ res”文件夹下创建一个目录,并将其命名为xml,然后创建一个资源文件,并将其命名为file_paths.xml)；然后删除其中的所有代码(会有几行)并粘贴以下内容：

<?xml version="1.0" enCoding="utf-8"?><paths xmlns:androID="http://schemas.androID.com/apk/res/androID"><external-path name="my_images"       path="AndroID/data/com.serjardovic.firebasesandBox/files/Pictures" /></paths>

确保将com.serjardovic.firebasesandBox更改为您自己的包名称！

效果100％-玩得开心！

总结

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