我一直在使用Camera Intent来捕捉图像。这是第一次完美运行，我能够捕获图像并在ImageView中显示。但是当我第二次尝试拍摄不同的图像时，它仍会显示相同的旧图像。
这是我的Camera Intent和onActivityResult（）
的代码 Uri selectedImage;
private Uri imageUri;
private void activeTakePhoto() {
Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
File photo = new File(Environment.getExternalStorageDirectory(), "Pic.jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(photo));
imageUri = Uri.fromFile(photo);
startActivityForResult(intent,REQUEST_IMAGE_CAPTURE);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode) {
case RESULT_LOAD_IMAGE:
if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK & null != data) {
selectedImage = data.getData();
imageView.setImageURI(selectedImage);
}
break;
case REQUEST_IMAGE_CAPTURE:
if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
try {
selectedImage = imageUri;
getContentResolver().notifyChange(selectedImage, null);
imageView.setImageURI(imageUri);
} catch (Exception e) {
Toast.makeText(this, "Failed to load", Toast.LENGTH_SHORT)
.show();
Log.e("Camera", e.toString());
}
Log.e("A", "AAA");
}
}
}
submit.setOnClickListener(new View.OnClickListener() { // back to Activity A listView
@Override
public void onClick(View v) {
Intent returnIntent = new Intent();
amount = Amount.getText().toString();
description = Description.getText().toString();
type = spinnerType.getSelectedItem().toString();
returnIntent.putExtra("type", type);
returnIntent.putExtra("description", description);
returnIntent.putExtra("amount", amount);
if(selectedImage!=null) {
returnIntent.putExtra("img_uri", selectedImage.toString());
}
setResult(Activity.RESULT_OK, returnIntent);
finish();
}
});
活动A
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() { // if listView is clicked
@Override
public void onItemClick(AdapterView<?> a, View v, int position, long id) { // if list is clicked
mClickedPosition = position;
Object o = listview.getItemAtPosition(position);
ImageAndText image = (ImageAndText) o;
String type = image.getType();
String amount = image.getAmount();
String description = image.getDescription();
Uri photo = image.getImage();
String[] type1 = type.split(":");
String[] amount1 = amount.split(":");
String[] description1 = description.split(":");
Intent i = new Intent(getApplication(), AddMoreClaims.class);
i.putExtra("type", type1[1].toString().trim());
i.putExtra("amount", amount1[1].toString().trim());
i.putExtra("description", description1[1].toString().trim());
i.putExtra("photo", photo);
startActivityForResult(i, PROJECT_REQUEST_CODE);
}
});
已修改（添加TimeStamp）
private void activeTakePhoto() {
String filename = "Pic_" + System.currentTimeMillis() + ".jpg";
Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
File photo = new File(Environment.getExternalStorageDirectory(), "Pic.jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(photo,filename));
imageUri = Uri.fromFile(photo,filename);
startActivityForResult(intent, REQUEST_IMAGE_CAPTURE);
}
答案 0 :(得分：2)
如果我们查看ImageView的来源，则setImageURI()方法会以if检查开头，类似于：
public void setImageURI(@Nullable Uri uri) {
if (mResource != 0 ||
(mUri != uri &&
(uri == null || mUri == null || !uri.equals(mUri)))) {
// Drawable resolution and update code
}
}
正如您在!uri.equals(mUri)中看到的那样，ImageView如果Uri传入已设置的方法equals()，则不会自行刷新。您的代码每次都保存到同一个文件中，因此Uri始终是相同的。
在致电imageView.setImageURI(null);之前，只需致电imageView.setImageURI(imageUri);即可。或者，您可以每次保存到不同的文件;例如，通过向文件名添加时间戳。
答案 1 :(得分：0)
问题可能是ImageView没有刷新内容。 更改内容后，您应该尝试调用invalidate方法。
imageView.setImageURI(imageUri);
imageView.invalidate();
答案 2 :(得分：0)
>To display image which is captured by camera on second time, Simply **update** the first element from database after completing the operation .
公共类MainActivity扩展了AppCompatActivity {
private static final int CAMERA_REQUEST = 1;
private static final int GALLERY_IMAGE = 2;
private static final String TAG = "";
Button captureImage;
ImageView imageView;
ImageDatabase database;
Bitmap b,theImage;
MainActivity CameraActivity = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
CameraActivity = this;
imageView = (ImageView) findViewById(R.id.image_view);
database = new ImageDatabase(this);
//Set OnClick Listener to button view
captureImage = (Button) findViewById(R.id.capture_image);
captureImage.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
isStoragePermissionGranted();
}
});
//long press on image
imageView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
isStoragePermissionGranted();
return true;
}
});
}
private void startDialog() {
AlertDialog.Builder myAlertDialog = new AlertDialog.Builder(
CameraActivity);
myAlertDialog.setTitle("Upload Pictures Option");
myAlertDialog.setMessage("How do you want to set your picture?");
myAlertDialog.setPositiveButton("Gallery",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface arg0, int arg1) {
Intent i = new Intent();
i.setType("image/*");
i.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(i.createChooser(i, "Result load Image")
, GALLERY_IMAGE);
}
});
myAlertDialog.setNegativeButton("Camera",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface arg0, int arg1) {
Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_REQUEST);
}
});
myAlertDialog.show();
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == CAMERA_REQUEST && resultCode == Activity.RESULT_OK) {
theImage = (Bitmap) data.getExtras().get("data");
}
if (requestCode == GALLERY_IMAGE && resultCode == RESULT_OK) {
try {
Uri imageUri = data.getData();
InputStream imageStream = getContentResolver().openInputStream(imageUri);
theImage = BitmapFactory.decodeStream(imageStream);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
ByteArrayOutputStream stream = new ByteArrayOutputStream();
theImage.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
SQLiteDatabase db = database.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(ImageDatabase.KEY_IMG_URL, byteArray);
db.insert(ImageDatabase.TABLE_NAME, null, values);
db.update(ImageDatabase.TABLE_NAME, values, null, null);
db.close();
}
public void getTheImage() {
SQLiteDatabase db = database.getReadableDatabase();
Cursor cursor = (Cursor) db.rawQuery(" SELECT * FROM " + ImageDatabase.TABLE_NAME,
null, null);
if (cursor.moveToFirst()) {
byte[] imgByte = cursor.getBlob(cursor.getColumnIndex(ImageDatabase.KEY_IMG_URL));
cursor.close();
b = BitmapFactory.decodeByteArray(imgByte, 0, imgByte.length);
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
imageView.setImageBitmap(b);
}
//Storage permission
public boolean isStoragePermissionGranted() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
== PackageManager.PERMISSION_GRANTED) {
Log.v(TAG, "Permission is granted");
startDialog();
return true;
} else {
Log.v(TAG, "Permission is revoked");
ActivityCompat.requestPermissions(this, new String[]
{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
return false;
}
} else { //permission is automatically granted on sdk<23 upon installation
Log.v(TAG, "Permission is granted");
startDialog();
return true;
}
}
@Override
protected void onStart() {
super.onStart();
getTheImage();
}
}