从存储中获取图像在 Android 中不起作用
Get image from storage not working in Android
我正在捕获图像并将其存储在移动设备的存储器中,但是当我获取此图像时,它无法在图像视图中显示任何内容。我已经尝试了很多代码来从文件中获取图像,但是 none 它们在我的模拟器或真正的三星设备中工作。
enter code here
imageHolder = (ImageView)findViewById(R.id.captured_photo);
Button capturedImageButton = (Button)findViewById(R.id.photo_button);
capturedImageButton.setOnClickListener( new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent photoCaptureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(photoCaptureIntent, requestCode);
}
});
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(this.requestCode == requestCode && resultCode == RESULT_OK){
Bitmap bitmap = (Bitmap)data.getExtras().get("data");
String partFilename = currentDateFormat();
storeCameraPhotoInSDCard(bitmap, partFilename);
// display the image from SD Card to ImageView Control
String storeFilename = "photo_" + partFilename + ".jpg";
Bitmap mBitmap = getImageFileFromSDCard(storeFilename);
imageHolder.setImageBitmap(mBitmap);
}
}
private String currentDateFormat(){
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMdd_HH_mm_ss");
String currentTimeStamp = dateFormat.format(new Date());
return currentTimeStamp;
}
private void storeCameraPhotoInSDCard(Bitmap bitmap, String currentDate){
File outputFile = new File(Environment.getExternalStorageDirectory(), "photo_" + currentDate + ".jpg");
try {
FileOutputStream fileOutputStream = new FileOutputStream(outputFile);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fileOutputStream);
fileOutputStream.flush();
fileOutputStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private Bitmap getImageFileFromSDCard(String filename){
/* Bitmap bitmap = null;
File imageFile = new File(Environment.getExternalStorageDirectory() + filename);
try {
FileInputStream fis = new FileInputStream(imageFile);
bitmap = BitmapFactory.decodeStream(fis);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return bitmap; */
File imageFile = new File(Environment.getExternalStorageDirectory() + filename);
// File imgFile = new File(filename);
//("/sdcard/Images/test_image.jpg");
Bitmap myBitmap;
if(imageFile.exists()){
myBitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
// ImageView myImage = (ImageView) findViewById(R.id.imageviewTest);
// myImage.setImageBitmap(myBitmap);
return myBitmap;
}
return null;
}
首先确保您已经在 "AndroidManifest" 中声明了 "Access External Storage" 和 "Access Hardware Camera" 权限,如果您使用的是 Android 版本 23 或 23+,那么您有在 运行 时间获得权限。
如果这不是问题,请使用下面给出的代码,它对我来说工作正常。
对于相机:
Intent takePicture = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(takePicture, ACTION_REQUEST_CAMERA);
画廊:
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
Intent chooser = Intent.createChooser(intent, "Choose a Picture");
startActivityForResult(chooser, ACTION_REQUEST_GALLERY);
OnActivityResultMethod:
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
switch (requestCode) {
case ACTION_REQUEST_GALLERY:
Uri galleryImageUri = data.getData();
try{
Log.e("Image Path Gallery" , getPath(getActivity() , galleryImageUri));
selectedImagePath = getPath(getActivity() , galleryImageUri);
} catch (Exception ex){
ex.printStackTrace();
Log.e("Image Path Gallery" , galleryImageUri.getPath());
selectedImagePath = galleryImageUri.getPath();
}
break;
case ACTION_REQUEST_CAMERA:
// Uri cameraImageUri = initialURI;
Uri cameraImageUri = data.getData();
Log.e("Image Path Camera" , getPath(cameraImageUri));
selectedImagePath = getPath(cameraImageUri);
break;
}
}
}
获取相机返回图像路径的方法:
/**
* helper to retrieve the path of an image URI
*/
public String getPath(Uri uri) {
// just some safety built in
if( uri == null ) {
// TODO perform some logging or show user feedback
return null;
}
// try to retrieve the image from the media store first
// this will only work for images selected from gallery
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = getActivity().managedQuery(uri, projection, null, null, null);
if( cursor != null ){
int column_index = cursor
.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
// this is our fallback here
return uri.getPath();
}
我正在捕获图像并将其存储在移动设备的存储器中,但是当我获取此图像时,它无法在图像视图中显示任何内容。我已经尝试了很多代码来从文件中获取图像,但是 none 它们在我的模拟器或真正的三星设备中工作。
enter code here
imageHolder = (ImageView)findViewById(R.id.captured_photo);
Button capturedImageButton = (Button)findViewById(R.id.photo_button);
capturedImageButton.setOnClickListener( new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent photoCaptureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(photoCaptureIntent, requestCode);
}
});
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(this.requestCode == requestCode && resultCode == RESULT_OK){
Bitmap bitmap = (Bitmap)data.getExtras().get("data");
String partFilename = currentDateFormat();
storeCameraPhotoInSDCard(bitmap, partFilename);
// display the image from SD Card to ImageView Control
String storeFilename = "photo_" + partFilename + ".jpg";
Bitmap mBitmap = getImageFileFromSDCard(storeFilename);
imageHolder.setImageBitmap(mBitmap);
}
}
private String currentDateFormat(){
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMdd_HH_mm_ss");
String currentTimeStamp = dateFormat.format(new Date());
return currentTimeStamp;
}
private void storeCameraPhotoInSDCard(Bitmap bitmap, String currentDate){
File outputFile = new File(Environment.getExternalStorageDirectory(), "photo_" + currentDate + ".jpg");
try {
FileOutputStream fileOutputStream = new FileOutputStream(outputFile);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fileOutputStream);
fileOutputStream.flush();
fileOutputStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private Bitmap getImageFileFromSDCard(String filename){
/* Bitmap bitmap = null;
File imageFile = new File(Environment.getExternalStorageDirectory() + filename);
try {
FileInputStream fis = new FileInputStream(imageFile);
bitmap = BitmapFactory.decodeStream(fis);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return bitmap; */
File imageFile = new File(Environment.getExternalStorageDirectory() + filename);
// File imgFile = new File(filename);
//("/sdcard/Images/test_image.jpg");
Bitmap myBitmap;
if(imageFile.exists()){
myBitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
// ImageView myImage = (ImageView) findViewById(R.id.imageviewTest);
// myImage.setImageBitmap(myBitmap);
return myBitmap;
}
return null;
}
首先确保您已经在 "AndroidManifest" 中声明了 "Access External Storage" 和 "Access Hardware Camera" 权限,如果您使用的是 Android 版本 23 或 23+,那么您有在 运行 时间获得权限。 如果这不是问题,请使用下面给出的代码,它对我来说工作正常。
对于相机:
Intent takePicture = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(takePicture, ACTION_REQUEST_CAMERA);
画廊:
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
Intent chooser = Intent.createChooser(intent, "Choose a Picture");
startActivityForResult(chooser, ACTION_REQUEST_GALLERY);
OnActivityResultMethod:
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
switch (requestCode) {
case ACTION_REQUEST_GALLERY:
Uri galleryImageUri = data.getData();
try{
Log.e("Image Path Gallery" , getPath(getActivity() , galleryImageUri));
selectedImagePath = getPath(getActivity() , galleryImageUri);
} catch (Exception ex){
ex.printStackTrace();
Log.e("Image Path Gallery" , galleryImageUri.getPath());
selectedImagePath = galleryImageUri.getPath();
}
break;
case ACTION_REQUEST_CAMERA:
// Uri cameraImageUri = initialURI;
Uri cameraImageUri = data.getData();
Log.e("Image Path Camera" , getPath(cameraImageUri));
selectedImagePath = getPath(cameraImageUri);
break;
}
}
}
获取相机返回图像路径的方法:
/**
* helper to retrieve the path of an image URI
*/
public String getPath(Uri uri) {
// just some safety built in
if( uri == null ) {
// TODO perform some logging or show user feedback
return null;
}
// try to retrieve the image from the media store first
// this will only work for images selected from gallery
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = getActivity().managedQuery(uri, projection, null, null, null);
if( cursor != null ){
int column_index = cursor
.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
// this is our fallback here
return uri.getPath();
}