我正在尝试允许用户从相机和图库中选择图像，并使用所选图像更新图像视图。如果用户从他们的画廊中选择一张图片，我这样做会很成功，但是如果他们选择使用相机拍摄照片，我会得到一个空值。我不确定为什么，清单文件中有所有必要的权限，例如写入和读取外部存储。
//Creates popup and allows user to select book image from gallery or camera.
public void selectImageMenu(final View v) {
PopupMenu popup = new PopupMenu(v.getContext(), v);
popup.getMenuInflater().inflate(R.menu.gallery_menu, popup.getMenu());
popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
@Override
public boolean onMenuItemClick(MenuItem item) {
switch (item.getItemId()) {
case R.id.openCamera:
openCamera();
return true;
case R.id.openGallery:
openGallery();
return true;
default:
return true;
}
}
});
popup.show();
}
//checks permission and if it's granted allows user the choice of choosing an image from gallery or camera
public void uploadImagePost(View view) {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.READ_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
} else {
selectImageMenu(view);
}
}
//opens camera to allow user to take a picture.
public void openCamera() {
Intent takePicture = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(takePicture, 0);//zero can be replaced with any action code
}
//opens gallery to allow user to choose a book image
public void openGallery() {
Intent pickPhoto = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(pickPhoto, 1);//one can be replaced with any action code
}
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
super.onActivityResult(requestCode, resultCode, imageReturnedIntent);
switch (requestCode) {
case 0:
if (resultCode == RESULT_OK) {
selectedImageUri = imageReturnedIntent.getData();
Glide
.with(CreatePostActivity.this)
.load(selectedImageUri)
.placeholder(R.drawable.bookshelf)
.into(bookImage);
}
break;
case 1:
if (resultCode == RESULT_OK) {
selectedImageUri = imageReturnedIntent.getData();
Glide
.with(CreatePostActivity.this)
.load(selectedImageUri)
.placeholder(R.drawable.bookshelf)
.fitCenter()
.into(bookImage);
break;
}
}
}
答案 0 :(得分：0)
在您的代码中尝试
case 0:
if (resultCode == RESULT_OK) {
Bundle extras = imageReturnedIntent.getExtras();
bitmap = (Bitmap)extras.get("data");
bookImage.setImageBitmap(bitmap);
}
还有另一种方法，即在加载图像之前将图像存储到外部文件目录中。 检查一下
btnCamera.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (cameraIntent.resolveActivity(getPackageManager()) != null) {
File pictureFile = null;
pictureFile = getPictureFile();
if (pictureFile != null) {
Uri photoURI = FileProvider.getUriForFile(activity,
"com.xyx.yourproject",pictureFile);
cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(cameraIntent,CAMERA_REQUESTCODE);
}
}
dialog.dismiss();
}
});
保存到位置并获取图像的路径
private File getPictureFile() {
String timeStamp = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date());
String pictureFile = "pic_" + timeStamp;
File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
File image = null;
try {
image = File.createTempFile(pictureFile, ".jpg", storageDir);
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(activity,
"Photo file can't be created, please try again",
Toast.LENGTH_SHORT).show();
}
pictureFilePath = image.getAbsolutePath();
return image;
}
最后是onActivityResult
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CAMERA_REQUESTCODE && resultCode == RESULT_OK) {
File imgFile = new File(pictureFilePath);
/** use imgFile to print into your image view---code to print the image*/
} else if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK) {
/**-------your code*/
}
}
要获得访问本地文件存储目录的权限，请在清单文件中添加这些文件
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="com.xyz.yourpath"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/paths" />
</provider>
您必须创建一个资源文件“路径”，以在res / xml中指定您的外部路径
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="yourfiles"
path="Android/data/com.xyz.yourpackagename/files/Pictures" />
</paths>
现在图像将存储到外部路径，因此您可以使用文件路径将图像打印到图像视图中
答案 1 :(得分：0)
要从相机中获取正确的图像，您必须提供相机应用可以写入的文件：
static final int REQUEST_TAKE_PHOTO = 1;
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(this,
"com.example.android.fileprovider",
photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
}
}
}
然后在带有REQUEST_TAKE_PHOTO的活动结果上，只需读取您使用createImageFile创建的文件或缩略图位图对象，这些文件将作为额外的“数据”字段返回
您可以在这里找到所有答案：https://developer.android.com/training/camera/photobasics#java