android Camera拍照

通过Camera进行拍照步骤：

调用Camera的open()方法打开相机。该方法默认打开后置摄像头。如果需要打开指定摄像头，可以为该方法传入摄像头ID。

调用Camera的getParameters()方法获取拍照参数。该方法返回一个Camera.Parameters对象

调用Camera.Parameters对象方法设置拍照参数

调用Camera的startPreview()方法开始预览取景，在预览取景之前需要调用Camera的setPreviewDisplay(SurfaceHolder holder)方法设置使用哪个SurfaceView来显示取景照片

调用Camera的takePicture()方法进行拍照

结束程序时，调用Camera的stopPreview()结束取景预览，并调用release()方法释放资源

实例代码：

Activity：

import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.content.DialogInterface.OnClickListener;import android.graphics.Bitmap;import android.graphics.Bitmap.CompressFormat;import android.graphics.BitmapFactory;import android.graphics.ImageFormat;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.os.Environment;import android.util.DisplayMetrics;import android.view.Display;import android.view.SurfaceHolder;import android.view.SurfaceHolder.Callback;import android.view.SurfaceView;import android.view.View;import android.view.Window;import android.view.WindowManager;import android.widget.EditText;import android.widget.ImageView;public class CaptureImage extends Activity{SurfaceView sView;SurfaceHolder surfaceHolder;int screenWidth, screenHeight;// 定义系统所用的照相机Camera camera;// 是否在预览中boolean isPreview = false;@Overridepublic void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);// 设置全屏requestWindowFeature(Window.FEATURE_NO_TITLE);getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);setContentView(R.layout.main);// 获取窗口管理器WindowManager wm = getWindowManager();Display display = wm.getDefaultDisplay();DisplayMetrics metrics = new DisplayMetrics();// 获取屏幕的宽和高display.getMetrics(metrics);screenWidth = metrics.widthPixels;screenHeight = metrics.heightPixels;// 获取界面中SurfaceView组件sView = (SurfaceView) findViewById(R.id.sView);// 设置该Surface不需要自己维护缓冲区sView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);// 获得SurfaceView的SurfaceHoldersurfaceHolder = sView.getHolder();// 为surfaceHolder添加一个回调监听器surfaceHolder.addCallback(new Callback(){@Overridepublic void surfaceChanged(SurfaceHolder holder, int format,int width, int height){}@Overridepublic void surfaceCreated(SurfaceHolder holder){// 打开摄像头initCamera();}@Overridepublic void surfaceDestroyed(SurfaceHolder holder){// 如果camera不为null ,释放摄像头if (camera != null){if (isPreview) camera.stopPreview();camera.release();camera = null;}}});}private void initCamera(){if (!isPreview){// 此处默认打开后置摄像头。// 通过传入参数可以打开前置摄像头camera = Camera.open(0);  //①camera.setDisplayOrientation(90);}if (camera != null && !isPreview){try{Camera.Parameters parameters = camera.getParameters();// 设置预览照片的大小parameters.setPreviewSize(screenWidth, screenHeight);// 设置预览照片时每秒显示多少帧的最小值和最大值parameters.setPreviewFpsRange(4, 10);// 设置图片格式parameters.setPictureFormat(ImageFormat.JPEG);// 设置JPG照片的质量parameters.set("jpeg-quality", 85);// 设置照片的大小parameters.setPictureSize(screenWidth, screenHeight);// 通过SurfaceView显示取景画面camera.setPreviewDisplay(surfaceHolder);  //②// 开始预览camera.startPreview();  //③}catch (Exception e){e.printStackTrace();}isPreview = true;}}public void capture(View source){if (camera != null){// 控制摄像头自动对焦后才拍照camera.autoFocus(autoFocusCallback);  //④}}AutoFocusCallback autoFocusCallback = new AutoFocusCallback(){// 当自动对焦时激发该方法@Overridepublic void onAutoFocus(boolean success, Camera camera){if (success){// takePicture()方法需要传入3个监听器参数// 第1个监听器：当用户按下快门时激发该监听器// 第2个监听器：当相机获取原始照片时激发该监听器// 第3个监听器：当相机获取JPG照片时激发该监听器camera.takePicture(new ShutterCallback(){public void onShutter(){// 按下快门瞬间会执行此处代码}}, new PictureCallback(){public void onPictureTaken(byte[] data, Camera c){// 此处代码可以决定是否需要保存原始照片信息}}, myJpegCallback);  //⑤}}};PictureCallback myJpegCallback = new PictureCallback(){@Overridepublic void onPictureTaken(byte[] data, Camera camera){// 根据拍照所得的数据创建位图final Bitmap bm = BitmapFactory.decodeByteArray(data, 0,data.length);// 加载/layout/save.xml文件对应的布局资源View saveDialog = getLayoutInflater().inflate(R.layout.save,null);final EditText photoName = (EditText) saveDialog.findViewById(R.id.phone_name);// 获取saveDialog对话框上的ImageView组件ImageView show = (ImageView) saveDialog.findViewById(R.id.show);// 显示刚刚拍得的照片show.setImageBitmap(bm);// 使用对话框显示saveDialog组件new AlertDialog.Builder(CaptureImage.this).setView(saveDialog).setPositiveButton("保存", new OnClickListener(){@Overridepublic void onClick(DialogInterface dialog, int which){// 创建一个位于SD卡上的文件File file = new File(Environment.getExternalStorageDirectory(), photoName.getText().toString() + ".jpg");FileOutputStream outStream = null;try{// 打开指定文件对应的输出流outStream = new FileOutputStream(file);// 把位图输出到指定文件中bm.compress(CompressFormat.JPEG, 100,outStream);outStream.close();}catch (IOException e){e.printStackTrace();}}}).setNegativeButton("取消", null).show();// 重新浏览camera.stopPreview();camera.startPreview();isPreview = true;}};}

清单文件：

<!-- 授予程序使用摄像头的权限 --><uses-permission android:name="android.permission.CAMERA" /> <uses-feature android:name="android.hardware.camera" /> <uses-feature android:name="android.hardware.camera.autofocus" />