当活动打开时,会打开一个对话窗口,要求用户从相机拍摄照片,或从图库中选择一个。一旦我按下按钮打开相机,应用程序崩溃,我得到一个与获取URI相关的空指针异常。我一直在关注谷歌的演练,从相机中保存图片,似乎无法找到问题所在。
发生错误的行:
Uri photoURI = FileProvider.getUriForFile(CreatePostActivity.this,
"xyz.beerme.beerme.provider",
photoFile);
整个方法:
cameraButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if(intent.resolveActivity(getPackageManager()) != null){
File photoFile = null;
try{
photoFile = createImageFile();
} catch (IOException ex){
Snackbar message = Snackbar.make(findViewById(R.id.activity_create_post), "Error creating image", Snackbar.LENGTH_LONG);
message.show();
}
if(photoFile != null){
Uri photoURI = FileProvider.getUriForFile(CreatePostActivity.this,
"xyz.beerme.beerme.provider",
photoFile);
intent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(intent, REQUEST_CAMERA);
}
}
dialog.dismiss();
}
});
createImageFile方法:
private File createImageFile() throws IOException{
String timeStamp = new SimpleDateFormat("yyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_beerme";
File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
File image = File.createTempFile(
imageFileName,
".jpg",
storageDir
);
mCurrentPhotoPath = image.getAbsolutePath();
return image;
}
清单:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="xyz.beerme.beerme">
<!-- To auto-complete the email text field in the login form with the user's emails -->
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.READ_PROFILE" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme"
tools:replace="android:supportsRtl">
<meta-data
android:name="com.google.android.geo.API_KEY"
android:value="redacted" />
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="xyz.beerme.beerme.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths" ></meta-data>
</provider>
<activity android:name=".PostsActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.categroy.LAUNCHER"/>
</intent-filter>
</activity>
<activity android:name=".CreatePostActivity"></activity>
</application>
</manifest>
file_paths.xml
<?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/xyz.beerme.beerme/files/Pictures" />
</paths>
答案 0 :(得分:0)
尝试使用以下createImageFile方法代码
private File createImageFile() {
File storageDir = context.getExternalFilesDir(Environment.DIRECTORY_PICTURES);
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
// path = path + (timeStamp + "1jpg");
try {
file = File.createTempFile(timeStamp, ".jpg", storageDir);
} catch (IOException e) {
e.printStackTrace();
}
if (Build.VERSION.SDK_INT >= 24)
mCurrentPhotoPath = String.valueOf(FileProvider.getUriForFile(MainActivity.this,
BuildConfig.APPLICATION_ID + ".provider", file));
else
mCurrentPhotoPath = String.valueOf(Uri.fromFile(file));
return file;
}
答案 1 :(得分:0)
如果将来有人发现这个,我输入“provider”而不是“fileprovider”。由于提供者不存在,这是异常的来源。