我开始理解 andriod 应用程序代码并在我的设备上运行它。但是，当我运行代码并单击按钮时，设备说不幸的是相机已停止。如何解决此问题。这是我的 PhotoIntentActivity.java
package piyushs.camera;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.app.Activity;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import android.widget.FrameLayout;
public class PhotoIntentActivity extends Activity
{
private Camera mCamera;
private CameraPreview mPreview;
public static final int MEDIA_TYPE_IMAGE = 1;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_photo_intent);
Button captureButton = (Button) findViewById(R.id.button_capture);
System.out.println("Starting!");
// Create an instance of Camera
mCamera = getCameraInstance();
// Create our Preview view and set it as the content of our activity.
mPreview = new CameraPreview(this, mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(mPreview);
final PictureCallback mPicture = new PictureCallback()
{
public void onPictureTaken(byte[] data, Camera camera)
{
File pictureFile = getOutputMediaFile(MEDIA_TYPE_IMAGE);
if (pictureFile == null)
{
return;
}
try
{
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
MediaStore.Images.Media.insertImage(getContentResolver(), pictureFile.getAbsolutePath(), pictureFile.getName(), pictureFile.getName());
} catch (FileNotFoundException e)
{
} catch (IOException e)
{
}
}
};
// Add a listener to the Capture button
captureButton.setOnClickListener
(
new View.OnClickListener()
{
public void onClick(View v)
{
// get an image from the camera
System.out.println("Photo Taking!");
mCamera.takePicture(null, null, mPicture);
}
}
);
}// end of oncreate()
/** A safe way to get an instance of the Camera object. */
public static Camera getCameraInstance()
{
Camera c = null;
try
{
c = Camera.open(); // attempt to get a Camera instance
}
catch (Exception e)
{
// Camera is not available (in use or does not exist)
}
return c; // returns null if camera is unavailable
}
@Override
protected void onPause()
{
super.onPause();
releaseCamera(); // release the camera immediately on pause event
}
private void releaseCamera()
{
if (mCamera != null)
{
mCamera.release(); // release the camera for other applications
mCamera = null;
}
}
/** Create a File for saving an image or video */
private File getOutputMediaFile(int type)
{
// To be safe, you should check that the SDCard is mounted
// using Environment.getExternalStorageState() before doing this.
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "MyCameraApp");
// This location works best if you want the created images to be shared
// between applications and persist after your app has been uninstalled.
// Create the storage directory if it does not exist
if (! mediaStorageDir.exists())
{
if (! mediaStorageDir.mkdirs())
{
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_"+ timeStamp + ".jpg");
} else
{
return null;
}
return mediaFile;
}
}
这是我的 CameraPreview.java
package piyushs.camera;
import android.content.Context;
import android.hardware.Camera;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback
{
private SurfaceHolder mHolder;
private Camera mCamera;
public CameraPreview(Context context,Camera camera)
{
super(context);
mCamera = camera;
/*SurfaceView view = new SurfaceView(this);
c.setPreviewDisplay(view.getHolder());
c.startPreview();
c.takePicture(shutterCallback, rawPictureCallback, jpegPictureCallback);
* */
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceChanged(SurfaceHolder holder, int format, int width,int height)
{
// TODO Auto-generated method stub
if (mHolder.getSurface() == null)
{
// preview surface does not exist
return;
}
// stop preview before making changes
try
{
mCamera.stopPreview();
} catch (Exception e)
{
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
// start preview with new settings
try
{
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e)
{
}
}
public void surfaceCreated(SurfaceHolder holder)
{
// TODO Auto-generated method stub
}
public void surfaceDestroyed(SurfaceHolder holder)
{
// TODO Auto-generated method stub
}
}
这是我的 activity_photo_intent.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<FrameLayout
android:id="@+id/camera_preview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
/>
<Button
android:id="@+id/button_capture"
android:text="Capture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
/>
</LinearLayout>
我已经从构建我自己的相机应用程序中复制了大部分代码+ 自动捕获图像