我正在按照官方文档中的步骤操作: https ://developer.android.com/training/camera/photobasics#TaskPhotoView
我所做的一切都是一样的,但是,我收到了错误:
java.lang.NullPointerException:尝试在空对象引用上调用虚拟方法 'android.content.res.XmlResourceParser android.content.pm.PackageItemInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' java.lang.RuntimeException:将结果 ResultInfo{who=null, request=1, result=-1, data=Intent { }} 传递给活动 {com.rrgt19.partyfinder/com.rrgt19.partyfinder.activity.AddActivity} 失败: java.lang.NullPointerException:尝试在 android.app.ActivityThread.deliverResults(ActivityThread.java: 4324) 在 android.app.ActivityThread.handleSendResult(ActivityThread.java:4367) 在 android.app.ActivityThread.-wrap19(Unknown Source:0) 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:1649) 在android.os.Handler.dispatchMessage(Handler.java:105) 在 android.os.Looper.loop(Looper.java:164)
权限:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" android:required="true" />
文件提供者:
<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>
文件路径:
<?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.rrgt19.partyfinder/files/Pictures" />
</paths>
代码:
public class AddActivity extends AppCompatActivity implements View.OnClickListener {
private ImageView mPhotoImageView;
public static final int REQUEST_CODE_TAKE_PHOTO = 1;
private String mCurrentPhotoPath;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add);
// Views
mPhotoImageView = findViewById(R.id.photoImageView);
// Listeners
mPhotoImageView.setOnClickListener(this);
}
@Override
public void onClick(View v) {
if (v == mPhotoImageView) {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED && ContextCompat.checkSelfPermission(this,
Manifest.permission.CAMERA)
!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
} else {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
225);
}
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.CAMERA)) {
} else {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.CAMERA},
226);
}
} else {
dispatchTakePictureIntent();
}
}
}
private void dispatchTakePictureIntent() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (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(AddActivity.this, "com.example.android.fileprovider", photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(takePictureIntent, REQUEST_CODE_TAKE_PHOTO);
}
}
}
private File createImageFile() throws IOException {
// Create an image file name
String 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 intents
mCurrentPhotoPath = image.getAbsolutePath();
return image;
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_CODE_TAKE_PHOTO && resultCode == RESULT_OK) {
Bundle extras = data.getExtras(); // Aquí es null
Bitmap imageBitmap = (Bitmap) extras.get("data");
mPhotoImageView.setImageBitmap(imageBitmap);
}
}
}
目前,我设法正确拉出照片,但是当我单击“确定”进入我的活动时,应用程序关闭。我在模拟器和我的个人手机上使用 Android Nougat 7.0。
有任何想法吗?
首先,重要的是要注释您的应用程序必须使用以下权限:
如果设备运行 OS 6.0 或更高版本,手动请求权限很重要,请在使用相机之前调用此方法:
关于您在问题中提到的错误:
它起源于这里:
我建议您使用此方法获取文件的 Uri:
并在拍摄照片时将其更改为
onActivityResult()
,您将通过getContentResolver()收到照片:这样,相机将毫无问题地打开:
您将能够毫无问题地将相机拍摄的图像添加到您的
ImageView
:这将是您的完整课程的代码:
事实上,我遇到了你提到的同样的问题,我建议你检查这个应用程序:
https://github.com/Jorgesys/TakePicture
保存图像时必须保存文件名。
要在 APP 的 ImageView 中以低质量拍摄照片,它使用以下代码对我有用。
解决方案是这样放置
转换为String
photoURI
中的putextra
,所以拍照时apk不会关闭。