我是 Android 新手，我写了一个小程序来拍照并将它们保存在内部存储磁盘中。我的程序成功启动，但是当我拍照时，没有数据写入内存磁盘。
下面是我的代码。我错过了什么？
package com.lab2;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.app.Activity;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.ShutterCallback;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.os.Environment;
public class Lab2_cameraActivity extends Activity implements SurfaceHolder.Callback {
/** Called when the activity is first created. */
private Camera mCamera;
private SurfaceHolder mHolder;
private SurfaceView mSurfaceView;
private Button mbutton1;
private ShutterCallback shutter;
private PictureCallback raw;
private PictureCallback postview;
AutoFocusCallback AFCallback = new AutoFocusCallback(){
@Override
public void onAutoFocus(boolean success, Camera camera) {
// TODO Auto-generated method stub
if (success){
mCamera.takePicture(shutter, raw, postview, jpeg);//take photo
}else{
Toast.makeText(Lab2_cameraActivity.this, "in else...",Toast.LENGTH_LONG).show();
}
}
};
/*jpeg callback occurs when the compressed image is available*/
PictureCallback jpeg = new PictureCallback(){
@Override
public void onPictureTaken(byte[] data, Camera camera) {
// TODO Auto-generated method stub
FileOutputStream outStream = null;
File file = new File("/mnt/sdcard/");
try {
outStream = new FileOutputStream(file.toString()+"photo.jpg");
outStream.write(data);
outStream.close();
Toast.makeText(Lab2_cameraActivity.this, "Photo Saved...",Toast.LENGTH_LONG).show();
mCamera.startPreview();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
};
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
/*when surface destroyed, stop preview*/
if(mCamera != null){
mCamera.stopPreview();
mCamera.release();//release camera resources
mCamera = null;
}
}
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
mCamera = Camera.open();//open camera
try {
mCamera.setPreviewDisplay(holder);//set surface to display
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
// TODO Auto-generated method stub
/*when surface changed, reset camera parameters for preview*/
mCamera.getParameters();//get default parameters
Camera.Parameters parameters= mCamera.getParameters();
/*you can set your own parameters in there*/
mCamera.setParameters(parameters);//set parameters if parameters has been changed
mCamera.startPreview();
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mbutton1 = (Button)findViewById(R.id.button1);
mSurfaceView = (SurfaceView)findViewById(R.id.surfaceView);
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mbutton1.setOnClickListener(new Button.OnClickListener()
{
@Override
public void onClick(View v) {
mCamera.autoFocus(AFCallback);
}
});
}
}