自定义Camera之简单介绍

拍照界面：

因为取景框要有实时刷新的效果所以普通的view不行，一般使用surfaceView

上面的按钮是拍照按钮

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical"
     tools:context="com.example.cameratest1.MyCamera" >

     <Button
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:onClick="capture"
         android:text="Capture" />

     <SurfaceView
         android:id="@+id/preview"
         android:layout_width="match_parent"
         android:layout_height="match_parent" />

 </LinearLayout>

然后写一个Activity实现拍照的逻辑控制,MyCamera,

实现几个方法

拍照按钮点击事件

public void capture(View view){}

 获取Camera对象方法

private Camera getCamera(){}

开始预览相机内容方法，将Camera与SurfaceView进行绑定，
使Camera的实时预览效果显示在SurfaceView
 中

private void setStartPreview(Camera camera,SurfaceHolder holder){}

* 释放系统相机资源
private void releaseCamera(){}

全部代码

 public class MyCamera extends Activity implements SurfaceHolder.Callback{

     private Camera mCamera;
     private SurfaceView mPreview;

     private SurfaceHolder mHolder;
     private Camera.PictureCallback mPictureCallback = new Camera.PictureCallback() {

         @Override
         public void onPictureTaken(byte[] data, Camera camera) {
             // TODO Auto-generated method stub
             //这里的data是真实图片数据不是缩略图
             File tempFile = new File("/sdcard/tddemp.png");
             try {
                 FileOutputStream fos = new FileOutputStream(tempFile);
                 fos.write(data);//将拍到的数据写入文件
                 fos.close();
                 //将拍到的数据传递到resultActivity中显示出来
                 Intent intent = new Intent(MyCamera.this, ResultActivity.class);
                 intent.putExtra("picPath", tempFile.getAbsolutePath());
                 startActivity(intent);
                 MyCamera.this.finish();
             } catch (FileNotFoundException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             } catch (IOException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
         }
     };
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_my_camera);
         mPreview = (SurfaceView) findViewById(R.id.preview);
         mHolder = mPreview.getHolder();
         mHolder.addCallback(this);
     }
     public void capture(View view){
         //设置拍照参数
         Camera.Parameters parameters = mCamera.getParameters();
         parameters.setPictureFormat(ImageFormat.JPEG);//设置拍照格式
         parameters.setPictureSize(800, 400);//设置拍照大小
         parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);//设置自动对焦
         //获取最清晰的焦距
         mCamera.autoFocus(new Camera.AutoFocusCallback() {

             @Override
             public void onAutoFocus(boolean success, Camera camera) {
                 // TODO Auto-generated method stub
                 if (success) {
                     mCamera.takePicture(null, null, mPictureCallback);
                     //第三个参数是回调方法
                 }

             }
         });

     }

     /**
      * 使用系统相机需要以下方法
      */
     /**
      * 获取Camera对象
      * @return
      */
     private Camera getCamera(){
         //这里使用导入的是硬件的Camera,import android.hardware.Camera;
         Camera camera;
         camera = Camera.open();
         return camera;
     }
     /**
      * 开始预览相机内容,将Camera与SurfaceView进行绑定，
      * 使Camera的实时预览效果显示在SurfaceView
      * 中
      */
     private void setStartPreview(Camera camera,SurfaceHolder holder){
         try {
             camera.setPreviewDisplay(holder);
             camera.startPreview();
             camera.setDisplayOrientation(90);//系统默认显示横屏的Camera,旋转为竖屏
         } catch (IOException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }
     /**
      * 释放系统相机资源
      */
     private void releaseCamera(){

         if (mCamera!=null) {
             mCamera.setPreviewCallback(null);//去掉回调，取消与SuferView的关联
             mCamera.stopPreview();//停止取景
             mCamera.release();
             mCamera =null;
         }

     }
     /**
      * 将Camera的生命周期与Activity的生命周期进行绑定
      */
     @Override
     protected void onResume() {
         // TODO Auto-generated method stub
         super.onResume();
         if (mCamera == null) {
             mCamera = getCamera();
             if(mHolder != null){
                 setStartPreview(mCamera, mHolder);
             }
         }
     }
     @Override
     protected void onPause() {
         // TODO Auto-generated method stub
         super.onPause();
         releaseCamera();

     }
     @Override
     public void surfaceChanged(SurfaceHolder holder, int format, int width,
             int height) {
         // TODO Auto-generated method stub
         //重启
         mCamera.stopPreview();
         setStartPreview(mCamera, mHolder);
     }
     @Override
     public void surfaceCreated(SurfaceHolder holder) {
         // TODO Auto-generated method stub
         setStartPreview(mCamera, mHolder);
     }
     @Override
     public void surfaceDestroyed(SurfaceHolder holder) {
         // TODO Auto-generated method stub
         releaseCamera();
     }
 }

写一个ResultActivity，这样在拍照界面点击拍照按钮后，将图片在ResultActivtiy中获取显示

 public class ResultActivity extends Activity {

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_result);
         String path = getIntent().getStringExtra("picPath");

         ImageView imageView = (ImageView) findViewById(R.id.pic);

         try {
             FileInputStream fis = new FileInputStream(path);
             Bitmap bitmap = BitmapFactory.decodeStream(fis);
             /**
              * 让图像显示为竖屏，拍照时默认系统取景为横屏，存储的也是横屏的数据，这里需要做如下处理
              */
             Matrix matrix = new Matrix();//矩阵
             matrix.setRotate(90);//通过变换矩阵旋转角度
             bitmap = Bitmap.createBitmap(bitmap,0,0,bitmap.getWidth(),bitmap.getHeight(),matrix, true);
             imageView.setImageBitmap(bitmap);
         } catch (FileNotFoundException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
         //      Bitmap bitmap = BitmapFactory.decodeFile(path);
         //      imageView.setImageBitmap(bitmap);

     }
 }