相机在 Nougat 7.0 中无法工作

我的相机代码适用于所有 Android 版本，但在 Nougat 7.0 中出现以下错误：

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.toString()' on a null object reference

它在除 Android 7.0 之外的所有其他 Android 版本上都能完美运行。我已授予相机和图库的运行时权限，但相机仍然无法工作。这是相关代码：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (resultCode == RESULT_OK) {
        if(requestCode == Constants.CROPPED_PIC_REQUEST_CODE){
            CropImage.ActivityResult result = (CropImage.ActivityResult) data.getExtras().get(CropImage.CROP_IMAGE_EXTRA_RESULT);
            Uri selectedImageUri = result == null ? null : result.getUri();
            Bitmap bitmap = null;
            Log.d("SetUpProfile","Uri cropped is "+outputFileUri);
            bitmap = getBitmap(selectedImageUri);
    //                    bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), selectedImageUri);
            circleImageView.setImageBitmap(bitmap);
            finalBitmap = bitmap;
        }
        else if (requestCode == Constants.YOUR_SELECT_PICTURE_REQUEST_CODE) {
            final boolean isCamera;
            if (data == null) {
                isCamera = true;
            } else {
                final String action = data.getAction();
                if (action == null) {
                    isCamera = false;
                } else {
                    isCamera = action.equals(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                }
            }

            Uri selectedImageUri;
            if (isCamera) {
                SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
                String value = prefs.getString("path", "error");
                selectedImageUri = Uri.parse(value);
            } else {
                selectedImageUri = data == null ? null : data.getData();
            }

            Intent i = new Intent(Five.this,CropImageActivity.class);
            i.putExtra("ImageURI", selectedImageUri.toString());
            startActivityForResult(i,Constants.CROPPED_PIC_REQUEST_CODE);

        }
    }
}

这是我的日志猫：-

FATAL EXCEPTION: main
Process: com.sancsvision.wayndr, PID: 31570
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=11, result=-1, data=Intent {  }} to activity {com.sancsvision.wayndr/com.sancsvision.wayndr.Five}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.toString()' on a null object reference                     
    at android.app.ActivityThread.deliverResults(ActivityThread.java:4053)              
    at android.app.ActivityThread.handleSendResult(ActivityThread.java:4096)        
    at android.app.ActivityThread.-wrap20(ActivityThread.java)                      
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1516)         
    at android.os.Handler.dispatchMessage(Handler.java:102)                     
    at android.os.Looper.loop(Looper.java:154)                      
    at android.app.ActivityThread.main(ActivityThread.java:6077)                        
    at java.lang.reflect.Method.invoke(Native Method)                       
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)      
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)                                                     
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.toString()' on a null object reference
    at com.sancsvision.wayndr.Five.onActivityResult(Five.java:259)
    at android.app.Activity.dispatchActivityResult(Activity.java:6917)
    at android.app.ActivityThread.deliverResults(ActivityThread.java:4049)
    at android.app.ActivityThread.handleSendResult(ActivityThread.java:4096) 
    at android.app.ActivityThread.-wrap20(ActivityThread.java) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1516) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:154) 
    at android.app.ActivityThread.main(ActivityThread.java:6077) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

尝试一下，一旦你拍照并保存到 SD 卡，并且在 Nougat 中取回 URI 时，这并不是造成问题的意图......

在您的应用程序上实现 FileProvider 非常容易。首先，您需要在 AndroidManifest.xml 的标签下添加 FileProvider 标签，如下所示：AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    ...
    <application
        ...
        <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="${applicationId}.provider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/provider_paths"/>
        </provider>
    </application>
</manifest>

然后在res文件夹下的xml文件夹中创建provider_paths.xml文件。如果文件夹不存在，则可能需要创建。

res/xml/provider_paths.xml

 <?xml version="1.0" encoding="utf-8"?>
    <paths xmlns:android="http://schemas.android.com/apk/res/android">
        <external-path name="external_files" path="."/>
    </paths>

完毕！ FileProvider 现已声明并可供使用。

最后一步是更改 MainActivity.java 中的以下代码行

 Uri photoURI = Uri.fromFile(createImageFile());

to

Uri photoURI = FileProvider.getUriForFile(MainActivity.this,
        BuildConfig.APPLICATION_ID + ".provider",
        createImageFile());

并做了 ！您的应用程序现在应该可以在任何 Android 版本（包括 Android Nougat）上完美运行。干杯！