我试图让相机意图在更高的API上运行，但是当我尝试时它会崩溃。我认为某些路径有问题，但我无法弄清楚是什么。它运行良好的API 23。
FATAL EXCEPTION: main
Process: ur.mi.android.wgplus05, PID: 22088
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.PackageItemInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' on a null object reference
at android.support.v4.content.FileProvider.parsePathStrategy(FileProvider.java:583)
at android.support.v4.content.FileProvider.getPathStrategy(FileProvider.java:557)
at android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:399)
at ur.mi.android.wgplus05.Camera.takePicture(Camera.java:50)
at ur.mi.android.wgplus05.PictureActivity.takePicture(PictureActivity.java:148)
at ur.mi.android.wgplus05.PictureActivity.checkPermission(PictureActivity.java:140)
at ur.mi.android.wgplus05.PictureActivity.onOptionsItemSelected(PictureActivity.java:101)
at android.app.Activity.onMenuItemSelected(Activity.java:3204)
at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:408)
at android.support.v7.app.AppCompatActivity.onMenuItemSelected(AppCompatActivity.java:195)
at android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:113)
at android.support.v7.app.AppCompatDelegateImplV9.onMenuItemSelected(AppCompatDelegateImplV9.java:679)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:156)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:969)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:959)
at android.support.v7.widget.ActionMenuView.invokeItem(ActionMenuView.java:623)
at android.support.v7.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:154)
at android.view.View.performClick(View.java:5610)
at android.view.View$PerformClick.run(View.java:22260)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
第50行：
Uri photoURI = FileProvider.getUriForFile(activityContext,
BuildConfig.APPLICATION_ID + ".genericfileprovider",
photoFile);
public class Camera {
PictureActivity activityContext;
private String currentPhotoPath;
public Camera(PictureActivity activityContext) {
this.activityContext = activityContext;
}
public void takePicture(int requestCode) {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (takePictureIntent.resolveActivity(activityContext.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
return;
}
// Continue only if the File was successfully created
if (photoFile != null) {
if(Build.VERSION.SDK_INT < 24){
Uri photoURI = Uri.fromFile(photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
activityContext.startActivityForResult(takePictureIntent, requestCode);
}
else {
Uri photoURI = FileProvider.getUriForFile(activityContext,
BuildConfig.APPLICATION_ID + ".genericfileprovider",
photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
activityContext.startActivityForResult(takePictureIntent, requestCode);
}
}
}
}
public String getCurrentPhotoPath() {
return currentPhotoPath;
}
public Bitmap getScaledBitmap(String path, Point targetSize) {
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, bmOptions);
int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;
int scaleFactor = Math.min(photoW / targetSize.x, photoH / targetSize.y);
bmOptions.inJustDecodeBounds = false;
bmOptions.inSampleSize = scaleFactor;
bmOptions.inPurgeable = true;
Bitmap bitmap = BitmapFactory.decodeFile(path, bmOptions);
return bitmap;
}
private File createImageFile() throws IOException {
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.ENGLISH).format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File image = File.createTempFile(imageFileName, ".jpg", storageDir);
currentPhotoPath = image.getAbsolutePath();
return image;
}
}
清单：
<?xml version="1.0" encoding="utf-8"?>
<uses-feature android:name="android.hardware.camera"
android:required="true"/>
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.hardware.camera.autofocus" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_icon_hdx"
android:label="@string/app_name"
android:roundIcon="@drawable/ic_icon_hdx"
android:supportsRtl="true"
android:theme="@style/Theme.AppCompat.Light.DarkActionBar">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".Finanzen" />
<activity android:name=".Einkaufsliste" />
<activity android:name=".Einkaufsliste2" />
<activity android:name=".toDoList" />
<activity android:name=".Settings" />
<activity android:name=".PictureActivity" />
<activity
android:name=".Putzplan"
android:windowSoftInputMode="adjustResize" />
<activity android:name=".Kalender" />
<provider
android:name=".GenericFileProvider"
android:authorities="${applicationId}.ur.mi.android.wgplus05.genericfileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/provider_paths"/>
</provider>
</application>
</manifest>
那是路径
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="external_files" path="."/>
</paths>
答案 0 :(得分：1)
android:authorities="${applicationId}.ur.mi.android.wgplus05.genericfileprovider"
BuildConfig.APPLICATION_ID + ".genericfileprovider"
这些不匹配。他们需要匹配。否则，FileProvider无法找到ContentProvider，因为您向getUriForFile()提供了无效的授权名称。
因此，例如，您可以将第一行更改为：
android:authorities="${applicationId}.genericfileprovider"
然后，这两个值将匹配（应用程序ID加.genericfileprovider）。
答案 1 :(得分：0)
getUriForFile中的第二个参数应与xml中的authorities属性匹配。
BuildConfig.APPLICATION_ID + ".ur.mi.android.wgplus05.genericfileprovider"