Java 图像uri没有';在我第一次调用应用程序中的相机后,不会更新
当我想在我抓拍一张照片后获取图像uri时,它总是什么也得不到,但在我再次抓拍后,它返回第一个uri,而不是当前uri。看起来它总是在最新的之前得到一个。以下是我的camerapreview代码:Java 图像uri没有';在我第一次调用应用程序中的相机后,不会更新,java,android,camera,uri,photo,Java,Android,Camera,Uri,Photo,当我想在我抓拍一张照片后获取图像uri时,它总是什么也得不到,但在我再次抓拍后,它返回第一个uri,而不是当前uri。看起来它总是在最新的之前得到一个。以下是我的camerapreview代码: public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback { private static final String TAG = "CameraPreview"; private Su
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private static final String TAG = "CameraPreview";
private SurfaceHolder mHolder;
private Camera mCamera;
public static final int MEDIA_TYPE_IMAGE = 1;
private Uri outputMediaFileUri;
private String outputMediaFileType;
public File pic;
public Uri uri;
public CameraPreview(Context context) {
super(context);
mHolder = getHolder();
mHolder.addCallback(this);
}
private static Camera getCameraInstance() {
Camera c = null;
try {
c = Camera.open();
} catch (Exception e) {
Log.d(TAG, "camera is not available");
}
return c;
}
public void surfaceCreated(SurfaceHolder holder) {
mCamera = getCameraInstance();
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
mHolder.removeCallback(this);
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
int rotation = getDisplayOrientation();
mCamera.setDisplayOrientation(90);
}
private File getOutputMediaFile(int type) {
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), TAG);
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d(TAG, "failed to create directory");
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
if (type == MEDIA_TYPE_IMAGE) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"prescription" + ".jpg");
outputMediaFileType = "image/*";
} else {
return null;
}
outputMediaFileUri = Uri.fromFile(mediaFile);
return mediaFile;
}
public Uri getOutputMediaFileUri() {
return outputMediaFileUri;
}
public String getOutputMediaFileType() {
return outputMediaFileType;
}
public void takePicture() {
mCamera.takePicture(null, null, new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
Log.i("camera", "file done");
if (pictureFile == null) {
Log.d(TAG, "Error creating media file, check storage permissions");
return;
}
try {
Log.i("camera", "do outputstream");
FileOutputStream fos = new FileOutputStream(pictureFile);
Log.i("camera", "after outputstream");
s = getOutputMediaFileUri().toString();
fos.write(data);
fos.close();
} catch (FileNotFoundException e) {
Log.d(TAG, "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d(TAG, "Error accessing file: " + e.getMessage());
}
}
});
}
public int getDisplayOrientation() {
Display display = ((WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int rotation = display.getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0:
degrees = 0;
break;
case Surface.ROTATION_90:
degrees = 90;
break;
case Surface.ROTATION_180:
degrees = 180;
break;
case Surface.ROTATION_270:
degrees = 270;
break;
}
android.hardware.Camera.CameraInfo camInfo =
new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(Camera.CameraInfo.CAMERA_FACING_BACK, camInfo);
int result = (camInfo.orientation - degrees + 360) % 360;
return result;
}
}
在调用camerapreview.takepicture()之后,我尝试调用camerapreview.outputMediaFileUri.toString(),但它不起作用。有人能帮我吗
更新:
我发现在主要活动中,mPreview.takePicture()总是在所有过程结束时运行:
Button buttonCapturePhoto = (Button) findViewById(R.id.button_capture_photo);
buttonCapturePhoto.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mPreview.takePicture();
path = mPreview.geturi;
goToFourthActivity(path);
}
}
});
每次,“path”将首先读取图像uri,然后执行mPreview.takePicture()。所以它将始终是以前的uri,我不知道为什么,如何修复它?您的代码
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"prescription" + ".jpg");
无条件地重用相同的文件名。难怪您会得到相同的URI。我认为这不是问题所在,我已经更新了导致问题的内容。当然,更新的代码不好。它做什么,就开始捕获,并设置路径。相机将在很久以后调用PictureTaken()。但是,您可能不想重复使用相同的固定文件名。因此,如果我想获得更新的uri,我应该怎么做?既然您说onPictureTaken()将运行得晚很多,我该如何修复它?感谢您提醒我重复的文件名。您可能应该从
onPictureTaken()
回调中gotoForHactivity(path)
。