<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent" >

  <SurfaceView
    android:id="@+id/surfaceView"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" />

  <RelativeLayout
    android:id="@+id/buttonlayout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:visibility="gone" >

    <Button
      android:id="@+id/takepicture"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentBottom="true"
      android:layout_alignParentRight="true"
      android:layout_marginRight="5dp"
      android:onClick="takepicture"
      android:text="@string/takepicture" />

    <Button
      android:id="@+id/autofocus"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignTop="@id/takepicture"
      android:layout_marginRight="20dp"
      android:layout_toLeftOf="@id/takepicture"
      android:onClick="takepicture"
      android:text="@string/autofocus" />
  </RelativeLayout>

</FrameLayout>

import java.io.File;
import java.io.FileOutputStream;

import android.app.Activity;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.os.Environment;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;

public class MainActivity extends Activity {
  private View layout;
  private Camera camera;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.main);

    layout = this.findViewById(R.id.buttonlayout);

    SurfaceView surfaceView = (SurfaceView) this
        .findViewById(R.id.surfaceView);
    surfaceView.getHolder()
        .setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    surfaceView.getHolder().setFixedSize(176, 144);
    surfaceView.getHolder().setKeepScreenOn(true);
    surfaceView.getHolder().addCallback(new SurfaceCallback());
  }

  public void takepicture(View v) {
    if (camera != null) {
      switch (v.getId()) {
      case R.id.takepicture:
        camera.takePicture(null, null, new MyPictureCallback());
        break;

      case R.id.autofocus:
        camera.autoFocus(null);
        break;
      }
    }
  }

  private final class MyPictureCallback implements PictureCallback {
    public void onPictureTaken(byte[] data, Camera camera) {
      try {
        File jpgFile = new File(
            Environment.getExternalStorageDirectory(),
            System.currentTimeMillis() + ".jpg");
        FileOutputStream outStream = new FileOutputStream(jpgFile);
        outStream.write(data);
        outStream.close();
        camera.startPreview();
      } catch (Exception e) {
        e.printStackTrace();
      }
    }

  }

  private final class SurfaceCallback implements Callback {
    public void surfaceCreated(SurfaceHolder holder) {
      try {
        camera = Camera.open();// 打開攝像頭
        Camera.Parameters parameters = camera.getParameters();
        // Log.i("MainActivity", parameters.flatten());
        parameters.setPreviewSize(800, 480);
        parameters.setPreviewFrameRate(5);
        parameters.setPictureSize(1024, 768);
        parameters.setJpegQuality(80);
        camera.setParameters(parameters);
        camera.setPreviewDisplay(holder);
        camera.startPreview();// 開始預覽
      } catch (Exception e) {
        e.printStackTrace();
      }
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
      if (camera != null) {
        camera.release();
        camera = null;
      }
    }

  }

  @Override
  public boolean onTouchEvent(MotionEvent event) {
    if (event.getAction() == MotionEvent.ACTION_DOWN) {
      layout.setVisibility(ViewGroup.VISIBLE);
      return true;
    }
    return super.onTouchEvent(event);
  }
}

 <uses-permission android:name="android.permission.CAMERA" />
  <!-- 在SDCard中創(chuàng)建與刪除文件權限 -->
  <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
  <!-- 往SDCard寫入數據權限 -->
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />