android-摄像头-调用前置摄像头

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.util.List;

import com.yxiaolv.camerasample.R;

import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.ShutterCallback;
import android.media.MediaScannerConnection;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.Toast;

public class CameraActivity extends Activity {  static final
String TAG =  "CAMERA ACTIVITY";

//Camera object Camera mCamera; //Preview surface SurfaceView
surfaceView; //Preview surface handle for callback SurfaceHolder
surfaceHolder; //Camera button Button btnCapture; //Note if
preview windows is on. boolean previewing;  int mCurrentCamIndex
= 0;  @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnCapture = (Button) findViewById(R.id.btn_capture); btnCapture.setOnClickListener(new Button.OnClickListener() {
public void onClick(View arg0)
{
if (previewing)
mCamera.takePicture(shutterCallback, rawPictureCallback,
jpegPictureCallback);
}
});
surfaceView = (SurfaceView) findViewById(R.id.surfaceView1); surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(new SurfaceViewCallback());
//surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

@Override public boolean onCreateOptionsMenu(Menu menu)
{ //
Inflate the menu; this adds items to the action bar if it is
present. getMenuInflater().inflate(R.menu.main, menu); return
true;
}
ShutterCallback shutterCallback = new ShutterCallback()
{

@Override public void onShutter() { } };
PictureCallback rawPictureCallback = new PictureCallback() {
@Override public void onPictureTaken(byte[] arg0, Camera arg1) {

}
};
PictureCallback jpegPictureCallback = new
PictureCallback() { @Override public void onPictureTaken(byte[]
arg0, Camera arg1) {

String fileName =
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM)
.toString()
+ File.separator
+ "PicTest_" + System.currentTimeMillis() + ".jpg"; File file = new File(fileName); if (!file.getParentFile().exists()) {
file.getParentFile().mkdir();
}
try {
BufferedOutputStream bos = new BufferedOutputStream(
new FileOutputStream(file));
bos.write(arg0);
bos.flush();
bos.close();
scanFileToPhotoAlbum(file.getAbsolutePath());
Toast.makeText(CameraActivity.this, "[Test] Photo take and store in" + file.toString(),Toast.LENGTH_LONG).show(); } catch
(Exception e)
{
Toast.makeText(CameraActivity.this, "Picture Failed" + e.toString(),
Toast.LENGTH_LONG).show();
}
};
};
public void scanFileToPhotoAlbum(String path) {

MediaScannerConnection.scanFile(CameraActivity.this,
new String[] { path }, null,
new MediaScannerConnection.OnScanCompletedListener()
{

public void onScanCompleted(String path, Uri uri)
{
Log.i("TAG", "Finished scanning " + path);
}
});
}
private final class SurfaceViewCallback implements android.view.SurfaceHolder.Callback {    public void
surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3)
{
if (previewing)

{
mCamera.stopPreview();
previewing = false;
}

try {
mCamera.setPreviewDisplay(arg0);
mCamera.startPreview();
previewing = true;
setCameraDisplayOrientation(CameraActivity.this, mCurrentCamIndex, mCamera); } catch (Exception e) {} } public
void surfaceCreated(SurfaceHolder holder) { //mCamera =
Camera.open();
//change to front camera
mCamera = openFrontFacingCameraGingerbread();
// get Camera parameters
Camera.Parameters params = mCamera.getParameters();

List<String> focusModes = params.getSupportedFocusModes();
if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
// Autofocus mode is supported
}
}

public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
previewing = false; }
}
private Camera openFrontFacingCameraGingerbread() {
int cameraCount = 0;
Camera cam = null;
Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
cameraCount = Camera.getNumberOfCameras();

for (int camIdx = 0; camIdx < cameraCount; camIdx++) {
Camera.getCameraInfo(camIdx, cameraInfo);
if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
try {
cam = Camera.open(camIdx);
mCurrentCamIndex = camIdx;
} catch (RuntimeException e) {
Log.e(TAG, "Camera failed to open: " + e.getLocalizedMessage());
}
}
}

return cam;
}  //根据横竖屏自动调节preview方向，Starting from API level 14, this method can be called when preview is active. private
static void setCameraDisplayOrientation(Activity activity,int
cameraId, Camera camera)
{
Camera.CameraInfo info = new Camera.CameraInfo();
Camera.getCameraInfo(cameraId, info);
int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();

//degrees  the angle that the picture will be rotated clockwise. Valid values are 0, 90, 180, and 270.
//The starting position is 0 (landscape).
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;
}
int result;
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT)
{
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360;  // compensate the mirror
}
else
{
// back-facing
result = (info.orientation - degrees + 360) % 360;
}
camera.setDisplayOrientation(result);
}

} ``` ```