您好，我正在使用相机和图库按钮。当我选择相机时，我会通过打开相机、拍照并通过 Intent 将照片发送到下一个 Activity 来显示。这很好用。
但是当我选择图库按钮时，它会打开图库图像，但不会在下一个 Activity 中显示图像。没有错误。只是一个空白的黑屏。
它显示为， 我/编舞:跳过了 2103 帧!应用程序可能在其主线程上做了太多工作。
请帮助解决这个问题。
谢谢。
public class TestCameraActivity extends AppCompatActivity {
private CameraPreview mImageSurfaceView;
public Camera camera = null;
public static final int MEDIA_TYPE_IMAGE = 1;
private static final int REQUEST_CAMERA_PERMISSION = 1;
private static final int REQUEST_WRITE_PERMISSION = 2;
private FrameLayout cameraPreviewLayout;
private float mDist;
private Bitmap bm;
private float ratio = 9f / 16f;
private Button gallery;
private int SELECT_FILE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.test_camera);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
cameraPreviewLayout = (FrameLayout) findViewById(R.id.camera_preview);
Button captureButton = (Button) findViewById(R.id.button);
gallery = (Button) findViewById(R.id.galleries);
gallery.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);//
startActivityForResult(Intent.createChooser(intent, "Select File"),SELECT_FILE);
}
});
captureButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
camera.takePicture(null, null, pictureCallback);
}
});
}
@Override
protected void onResume() {
super.onResume();
requestCameraPermission();
}
Camera.PictureCallback pictureCallback = new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
bm = BitmapFactory.decodeByteArray(data, 0, data.length);
if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
// Setting post rotate to 90
Matrix mtx = new Matrix();
mtx.postRotate(90);
bm = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), mtx, true);
bm = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), (int) (bm.getWidth() * ratio));
} else {// LANDSCAPE MODE
//No need to reverse width and height
Bitmap scaled = Bitmap.createScaledBitmap(bm, bm.getWidth(), bm.getHeight(), true);
bm = scaled;
}
if (bm == null) {
Toast.makeText(TestCameraActivity.this, "khoong duoc roi", Toast.LENGTH_LONG).show();
return;
}
// capturedImageHolder.setImageBitmap(bm);
Intent intent = new Intent(TestCameraActivity.this, CaptureResultActivity.class);
ByteArrayOutputStream bs = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.PNG, 60, bs);
intent.putExtra("bitmap", bs.toByteArray());
startActivity(intent);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestWritePermission();
} else {
asyncSave();
}
// camera.startPreview();
}
};
public void asyncSave() {
new AsyncTask<Bitmap, Void, Boolean>() {
@Override
protected Boolean doInBackground(Bitmap... bitmaps) {
return saveBitmapImage(bitmaps[0]);
}
@Override
protected void onPostExecute(Boolean aBoolean) {
if (aBoolean) {
Toast.makeText(TestCameraActivity.this, "Save Image Success", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(TestCameraActivity.this, "Failed to save image...", Toast.LENGTH_SHORT).show();
}
}
}.execute(bm);
}
private boolean saveBitmapImage(Bitmap bitmap) {
File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
if (pictureFile == null) {
Log.d("BBB", "Error creating media file, check storage permissions: ");
return false;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos);
// fos.write(data);
fos.close();
galleryAddPic(pictureFile);
return true;
} catch (FileNotFoundException e) {
Log.d("BBB", "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d("BBB", "Error accessing file: " + e.getMessage());
}
return false;
}
private static File getOutputMediaFile(int type) {
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "MyCameraApp");
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
if (type == MEDIA_TYPE_IMAGE) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"IMG_LINH" + timeStamp + ".jpg");
} else {
return null;
}
return mediaFile;
}
// zoom
@Override
public boolean onTouchEvent(MotionEvent event) {
// Get the pointer ID
Camera.Parameters params = camera.getParameters();
int action = event.getAction();
if (event.getPointerCount() > 1) {
// handle multi-touch events
if (action == MotionEvent.ACTION_POINTER_DOWN) {
mDist = getFingerSpacing(event);
} else if (action == MotionEvent.ACTION_MOVE && params.isZoomSupported()) {
camera.cancelAutoFocus();
handleZoom(event, params);
}
} else {
// handle single touch events
if (action == MotionEvent.ACTION_UP) {
handleFocus(event, params);
}
}
return true;
}
private void handleZoom(MotionEvent event, Camera.Parameters params) {
int maxZoom = params.getMaxZoom();
int zoom = params.getZoom();
float newDist = getFingerSpacing(event);
if (newDist > mDist) {
//zoom in
if (zoom < maxZoom)
zoom++;
} else if (newDist < mDist) {
//zoom out
if (zoom > 0)
zoom--;
}
mDist = newDist;
params.setZoom(zoom);
camera.setParameters(params);
}
public void handleFocus(MotionEvent event, Camera.Parameters params) {
int pointerId = event.getPointerId(0);
int pointerIndex = event.findPointerIndex(pointerId);
// Get the pointer's current position
float x = event.getX(pointerIndex);
float y = event.getY(pointerIndex);
List<String> supportedFocusModes = params.getSupportedFocusModes();
if (supportedFocusModes != null && supportedFocusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
camera.autoFocus(new Camera.AutoFocusCallback() {
@Override
public void onAutoFocus(boolean b, Camera camera) {
// currently set to auto-focus on single touch
}
});
}
}
/**
* Determine the space between the first two fingers
*/
private float getFingerSpacing(MotionEvent event) {
// ...
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return (float) Math.sqrt(x * x + y * y);
}
//Request Permission
private void requestCameraPermission() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.CAMERA)
!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.CAMERA)) {
} else {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.CAMERA},
REQUEST_CAMERA_PERMISSION);
}
} else {
camera = Camera.open();
mImageSurfaceView = new CameraPreview(this, camera);
cameraPreviewLayout.addView(mImageSurfaceView);
}
} else {
camera = Camera.open();
mImageSurfaceView = new CameraPreview(this, camera);
cameraPreviewLayout.addView(mImageSurfaceView);
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
@NonNull int[] grantResults) {
switch (requestCode) {
case REQUEST_CAMERA_PERMISSION: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
camera = Camera.open(0);
mImageSurfaceView = new CameraPreview(this, camera);
cameraPreviewLayout.addView(mImageSurfaceView);
} else {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
// permission denied, boo! Disable the
// functionality that depends on this permission.
}
return;
}
case REQUEST_WRITE_PERMISSION: {
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
asyncSave();
} else {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
// permission denied, boo! Disable the
// functionality that depends on this permission.
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
//Request Write Permission
private void requestWritePermission() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
// Here, thisActivity is the current activity
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
// Should we show an explanation?
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
REQUEST_WRITE_PERMISSION);
// }
} else {
asyncSave();
}
} else {
//api < 21
}
}
//Add photo to the gallery
private void galleryAddPic(File f) {
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
Uri contentUri = Uri.fromFile(f);
mediaScanIntent.setData(contentUri);
this.sendBroadcast(mediaScanIntent);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
try {
if (resultCode == Activity.RESULT_OK) {
if (requestCode == SELECT_FILE)
onSelectFromGalleryResult(data);
}
} catch (Exception e) {
Toast.makeText(this, "Please try again", Toast.LENGTH_LONG)
.show();
}
}
private static Bitmap StringToBitMap(String encodedString){
try {
byte [] encodeByte= Base64.decode(encodedString,Base64.DEFAULT);
Bitmap bitmap=BitmapFactory.decodeByteArray(encodeByte, 0, encodeByte.length);
return bitmap;
} catch(Exception e) {
e.getMessage();
return null;
}
}
private void onSelectFromGalleryResult(Intent data) {
Bitmap bm=null;
if (data != null) {
try {
bm = MediaStore.Images.Media.getBitmap(getApplicationContext().getContentResolver(), data.getData());
} catch (IOException e) {
e.printStackTrace();
}
Intent intent = new Intent(TestCameraActivity.this, CaptureResultActivity.class);
ByteArrayOutputStream bs = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.PNG, 60, bs);
intent.putExtra("bitmap", bs.toByteArray());
startActivity(intent);
}
}
}
最佳答案
首先要打开 Gallery，您需要根据 API 级别打开。在 API 19 之后，您需要以其他方式打开图库。
if (Build.VERSION.SDK_INT < 19) {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE_REQUEST);
} else {
Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("image/*");
startActivityForResult(intent, PICK_IMAGE_REQUEST);
}
在 ActivityResult() 上
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == PICK_IMAGE_REQUEST
&& resultCode == Activity.RESULT_OK) {
Uri uri = data.getData();
mImageCaptureUri = Uri.fromFile(new File(uriToFilename(uri)));
}
}
private String uriToFilename(Uri uri) {
String path = null;
if (Build.VERSION.SDK_INT < 11) {
path = RealPathUtil.getRealPathFromURI_BelowAPI11(getActivity(), uri);
} else if (Build.VERSION.SDK_INT < 19) {
path = RealPathUtil.getRealPathFromURI_API11to18(getActivity(), uri);
} else {
path = RealPathUtil.getRealPathFromURI_API19(getActivity(), uri);
}
return path;
}
这是 RealPathUtil 类
import android.annotation.SuppressLint;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.support.v4.content.CursorLoader;
public class RealPathUtil {
@SuppressLint("NewApi")
public static String getRealPathFromURI_API19(Context context, Uri uri) {
String filePath = "";
if (DocumentsContract.isDocumentUri(context, uri)) {
String wholeID = DocumentsContract.getDocumentId(uri);
// Split at colon, use second item in the array
String[] splits = wholeID.split(":");
if (splits.length == 2) {
String id = splits[1];
String[] column = { MediaStore.Images.Media.DATA };
// where id is equal to
String sel = MediaStore.Images.Media._ID + "=?";
Cursor cursor = context.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
column, sel, new String[] { id }, null);
int columnIndex = cursor.getColumnIndex(column[0]);
if (cursor.moveToFirst()) {
filePath = cursor.getString(columnIndex);
}
cursor.close();
}
} else {
filePath = uri.getPath();
}
return filePath;
}
@SuppressLint("NewApi")
public static String getRealPathFromURI_API11to18(Context context, Uri contentUri) {
String[] proj = { MediaStore.Images.Media.DATA };
String result = null;
CursorLoader cursorLoader = new CursorLoader(context, contentUri, proj, null, null, null);
Cursor cursor = cursorLoader.loadInBackground();
if (cursor != null) {
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
result = cursor.getString(column_index);
}
return result;
}
public static String getRealPathFromURI_BelowAPI11(Context context, Uri contentUri) {
String[] proj = { MediaStore.Images.Media.DATA };
Cursor cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
}
关于android - 如何从图库中选择图像并在另一个 Activity android中显示？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39436838/