Android：覆盖 Android 相机预览

Question

我正在使用相机 API 并调用相机。

我想在相机预览的顶部显示标题（用于品牌）。标题是 jpeg 图像。

是否可以？任何帮助表示赞赏。

提前致谢。

我的代码如下。

public class CameraActivity extends Activity {
    @Override
    protected void onPause() {

        super.onPause();
    }

    private static final int CAMERA_PIC_REQUEST = 2500;
    private Bitmap image2;
    private Bitmap bm;
    public static String imagepath;
    public static int x=1;
    private RdmsDbAdapter dbHelper;
    @Override



    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.header);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        //caling new incident
        if(IncidentFormActivity.incident_id == null || IncidentFormActivity.isDisable==true){
            //DBAdapter instance created and connection opened. 
            dbHelper = new RdmsDbAdapter(CameraActivity.this);
            dbHelper.open();

            //setting up flags
            NewIncidentHelper nih = new NewIncidentHelper();
            nih.setUpNewIncident();

            //setting up incident_id
            String Date= IncidentIdGenerator.getDate();
            String Time = IncidentIdGenerator.getTime();

            IncidentFormActivity.incident_id = IncidentIdGenerator.now("ddMMyyyyHHmmss");
            dbHelper.executeSQL("insert into incident values ('" + IncidentFormActivity.incident_id
                    + "', ' ', ' ', ' ', ' ', '"+Date+"', '0','0','0','0','0','0','0','0','0','"+Time+"')");
            dbHelper.close();
        }

        //calling camera
        Intent cameraIntent = new Intent(
                android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(cameraIntent, CAMERA_PIC_REQUEST);


    }
    public String getPath(Uri uri) {
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = managedQuery(uri, projection, null, null, null);
        int column_index = cursor
                .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    }

    //back key on phone pressed
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        switch (keyCode) {
        case KeyEvent.KEYCODE_BACK:
            Intent i= new Intent(CameraActivity.this, IncidentFormActivity.class);
            startActivity(i);
            this.finish();

            break;

        default:
            break;
        }
        return super.onKeyDown(keyCode, event);
    }

    //handle response came from camera when the picture is taken.
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == CAMERA_PIC_REQUEST && resultCode == RESULT_OK) {
                final ImageView img = new ImageView(this);
                img.setLayoutParams(new LayoutParams(100, 100));
                image2 = (Bitmap) data.getExtras().get("data");
                img.setImageBitmap(image2);
                String incident_ID = IncidentFormActivity.incident_id;
                //l2.addView(img);
                    imagepath="/sdcard/RDMS/"+incident_ID+ x + ".png";
                File file = new File(imagepath);
                try {
                     bm = Bitmap.createScaledBitmap( image2,400, 300, true);
                    file.createNewFile();
                    FileOutputStream ostream = new FileOutputStream(file);
                    bm.compress(CompressFormat.PNG, 90, ostream);
                    ostream.close(); 
                    //Initialising db class and inserting values
                    dbHelper = new RdmsDbAdapter(CameraActivity.this);
                    dbHelper.open();
                    dbHelper.executeSQL("insert into files values ('"+imagepath+"', '"+IncidentFormActivity.incident_id+"')");
                    dbHelper.close();

                } catch (Exception e) {
                    e.printStackTrace();
                    Toast.makeText(getApplicationContext(),"yourfirst  error message is "
                                            + e.toString(), 1000).show();
                }
                x++;
                final AlertDialog.Builder alert = new AlertDialog.Builder(
                        CameraActivity.this);

                alert.setTitle(getString(R.string.anotherimage));
                alert.setCancelable(false);
                //alert.setMessage("Play or Delete the Video selected");
                //alert.setIcon(R.drawable.vid_red);
                alert.setPositiveButton(getString(R.string.yes), new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        Intent sendingpage = new Intent(CameraActivity.this, CameraActivity.class);
                          startActivity(sendingpage);

                    }
                });
                alert.setNegativeButton(getString(R.string.no),
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                Intent callback = new Intent (CameraActivity.this, IncidentFormActivity.class);
                                startActivity(callback);
                            }
                        });

                alert.show();


            }
            if(resultCode==RESULT_CANCELED)
            {

                AlertDialog.Builder builder = new AlertDialog.Builder(CameraActivity.this);

                builder.setMessage(getString(R.string.areuexit)).setCancelable(
                        false).setPositiveButton(getString(R.string.yes),
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                Intent i= new Intent(CameraActivity.this, IncidentFormActivity.class);
                                startActivity(i);
                                CameraActivity.this.finish();
                            }
                        }).setNegativeButton(getString(R.string.no),
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                dialog.cancel();
                                Intent i= new Intent(CameraActivity.this, CameraActivity.class);                            startActivity(i);
                                CameraActivity.this.finish();
                            }
                        });

                builder.show();



            }
        }
    }

Answer 1

您可以使用SurfaceView并创建一个可以打开相机的自定义视图，并且可以相应地在XML中调整其大小。以下是伪代码。

创建一个

capturepreview.java

public class CapturePreview extends SurfaceView implements SurfaceHolder.Callback{

    public static Bitmap mBitmap;
    SurfaceHolder holder;
    static Camera mCamera;

    public CapturePreview(Context context, AttributeSet attrs) {
        super(context, attrs);

        holder = getHolder();
        holder.addCallback(this);
        holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

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

        Camera.Parameters parameters = mCamera.getParameters();
        parameters.getSupportedPreviewSizes();
        mCamera.setParameters(parameters);
        mCamera.startPreview();
    }
    @Override
    public void surfaceCreated(SurfaceHolder holder) {

        try {
            mCamera = Camera.open();
            mCamera.setPreviewDisplay(holder);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        mCamera.stopPreview();
        mCamera.release();
    }
    /***
     * 
     *  Take a picture and and convert it from bytes[] to Bitmap.
     *  
     */
    public static void takeAPicture(){  

        Camera.PictureCallback mPictureCallback = new PictureCallback() {
            @Override
            public void onPictureTaken(byte[] data, Camera camera) {

                BitmapFactory.Options options = new BitmapFactory.Options();
                mBitmap = BitmapFactory.decodeByteArray(data, 0, data.length, options);
            }
        };
        mCamera.takePicture(null, null, mPictureCallback);
    }
}

现在您必须包括在XML中使用SurfaceView创建的视图，例如 strong>

main.xml

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

  <FrameLayout 
  android:id="@+id/mySurfaceView"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content">

  <com.cam.CapturePreview 
  android:layout_width="fill_parent"
  android:layout_height="wrap_content">
  </com.cam.CapturePreview>

  </FrameLayout>

  <LinearLayout 
  android:layout_below="@id/mySurfaceView" 
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:layout_centerInParent="true"
  android:gravity="center">

  <ImageView android:id="@+id/myImageView" 
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:src="@drawable/icon"/>
  </LinearLayout>  

</RelativeLayout>

现在您可以在任何aciTivty中使用此main.xml，该将使用imageView打开相机。
谢谢....

Answer 2

您必须自己处理整个相机预览和拍照。查看位于 samples/ApiDemos/src/com/example/android/apis/graphics/CameraPreview 的示例。您可以在预览区域上拥有自己的布局并向其中添加图形。

示例链接

https://developer.android.com/training/camera/cameradirect#java< /a>

Answer 3

您可以在 FrameLayout 的帮助下做到这一点，如下所示：

<?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" >

  <android.view.SurfaceView
  android:id="@+id/surface"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent" />

<ImageView
    android:id = "@+id/header"
    android:layout_width = "wrap_content"
    android:layout_height = "wrap_content" />

</FrameLayout>

此 相机项目将为您提供帮助。

Answer 4

恐怕你必须自己实现相机预览屏幕。理论上，可以通过修改其布局或创建覆盖窗口来将覆盖添加到其他应用程序。第一种方法是不可能实现的，第二种方法我认为可以实现，但这是一种黑客和容易出错的方法。

实现您自己的相机活动并不是一项非常困难的任务，但相当具有挑战性。我建议您看一下默认的相机应用程序。这是其源代码：https://github.com/android/platform_packages_apps_camera。

Answer 5

看看你的XML会是这样的：

 <?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" >

<android.view.SurfaceView
 android:id="@+id/surface"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent" />

<ImageView
android:id = "@+id/header"
android:layout_width = "wrap_content"
android:layout_height = "wrap_content" />

</FrameLayout>

对于java代码，你应该在你的活动中扩展SurfaceHolder.Callback，然后将相机附加到表面视图，如下所示，它是我的完整代码，请小心位图和画布，这是棘手的部分:

 public class MainActivity extends Activity implements SurfaceHolder.Callback 
{
  private Camera camera = null;
  private SurfaceView cameraSurfaceView = null;
  private SurfaceHolder cameraSurfaceHolder = null;
  private boolean previewing = false;
  RelativeLayout relativeLayout;





  private Button btnCapture = null;
  private Button btnsave = null;
  private Button btnshare = null;
  private boolean isSaved=false;
  private boolean isCaptured=false;

  @Override
  protected void onCreate(Bundle savedInstanceState) 
  {
    super.onCreate(savedInstanceState);

    getWindow().setFormat(PixelFormat.TRANSLUCENT);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(
                         WindowManager.LayoutParams.FLAG_FULLSCREEN,
                         WindowManager.LayoutParams.FLAG_FULLSCREEN);

    setContentView(R.layout.activity_main);

    relativeLayout=(RelativeLayout) findViewById(R.id.containerImg);
    relativeLayout.setDrawingCacheEnabled(true);
    cameraSurfaceView = (SurfaceView)
                                       findViewById(R.id.surfaceView1);
  //  cameraSurfaceView.setLayoutParams(new FrameLayout.LayoutParams(640, 480));
    cameraSurfaceHolder = cameraSurfaceView.getHolder();
    cameraSurfaceHolder.addCallback(this);
//    cameraSurfaceHolder.setType(SurfaceHolder.
  //                                               SURFACE_TYPE_PUSH_BUFFERS);




    btnCapture = (Button)findViewById(R.id.capturebtn);
    btnCapture.setOnClickListener(new OnClickListener() 
    {   
      @Override
      public void onClick(View v) 
      {
         camera.takePicture(cameraShutterCallback, 
                                       cameraPictureCallbackRaw,
                                       cameraPictureCallbackJpeg);
         isCaptured=true;
      }
    });
    btnsave = (Button)findViewById(R.id.savebtn);
    btnsave.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
             FrameLayout frm = (FrameLayout)findViewById(R.id.frameLayout1);
                frm.setDrawingCacheEnabled(true);
                frm.buildDrawingCache();
                Bitmap bitmap = frm.getDrawingCache();
                try {
                    File rootFile=new File(Environment.getExternalStorageDirectory().toString()+"/MYCAMERAOVERLAY");
                    rootFile.mkdirs();
                    Random generator = new Random();
                    int n = 10000;
                    n = generator.nextInt(n);
                    String fname = "Image-"+ n +".png";

                    File resultingfile = new File(rootFile, fname);

                    if (resultingfile.exists ()) resultingfile.delete (); 
                    try {
                           FileOutputStream Fout = new FileOutputStream(resultingfile);
                           bitmap.compress(CompressFormat.PNG, 100, Fout);
                           Fout.flush();
                           Fout.close();

                    } catch (FileNotFoundException e) {
                        Log.d("In Saving File", e + "");
                }
                } catch(IOException e){
                    Log.d("In Saving File", e + "");
                }
                isSaved=true;
            }
        });
    btnshare = (Button)findViewById(R.id.sharebtn);
    btnshare.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            if((isSaved)&&(isCaptured)){
                // TODO sharing what ever we saved 
                // take the path


            }

        }
    });
   } 


  ShutterCallback cameraShutterCallback = new ShutterCallback() 
  {  
    @Override
    public void onShutter() 
    {
      // TODO Auto-generated method stub   
    }
  };

  PictureCallback cameraPictureCallbackRaw = new PictureCallback() 
  {  
    @Override
    public void onPictureTaken(byte[] data, Camera camera) 
    {
      // TODO Auto-generated method stub   
    }
  };

  PictureCallback cameraPictureCallbackJpeg = new PictureCallback() 
  {  
    @Override
    public void onPictureTaken(byte[] data, Camera camera) 
    {
      // TODO Auto-generated method stub   
      Bitmap cameraBitmap = BitmapFactory.decodeByteArray
                                                                  (data, 0, data.length);

   int   wid = cameraBitmap.getWidth();
     int  hgt = cameraBitmap.getHeight();

    //  Toast.makeText(getApplicationContext(), wid+""+hgt, Toast.LENGTH_SHORT).show();
      Bitmap newImage = Bitmap.createBitmap
                                        (wid, hgt, Bitmap.Config.ARGB_8888);

      Canvas canvas = new Canvas(newImage);

      canvas.drawBitmap(cameraBitmap, 0f, 0f, null);

      camera.startPreview();

      newImage.recycle();
      newImage = null;

      Intent intent = new Intent();
      intent.setAction(Intent.ACTION_VIEW);

      startActivity(intent);

    }
  };

  @Override
  public void surfaceChanged(SurfaceHolder holder, 
                                       int format, int width, int height) 
  {
    // TODO Auto-generated method stub

    if(previewing)
    {
      camera.stopPreview();
      previewing = false;
    }
    try 
    {
      Camera.Parameters parameters = camera.getParameters();
      parameters.setPreviewSize(640, 480);
      parameters.setPictureSize(640, 480);
      if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
          camera.setDisplayOrientation(-90);

      }

     // parameters.setRotation(90);
      camera.setParameters(parameters);

      camera.setPreviewDisplay(cameraSurfaceHolder);
      camera.startPreview();
      previewing = true;
    } 
    catch (IOException e) 
    {
      // TODO Auto-generated catch block
      e.printStackTrace();  
    }
  }

  @Override
  public void surfaceCreated(SurfaceHolder holder) 
  {
    // TODO Auto-generated method stub
    try
    {
      camera = Camera.open();
    }
    catch(RuntimeException e)
    {
      Toast.makeText(getApplicationContext(), "Device camera  is not working properly, please try after sometime.", Toast.LENGTH_LONG).show();
    }
  }

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) 
  {
    // TODO Auto-generated method stub
      try{


    camera.stopPreview();
    camera.release();
    camera = null;
    previewing = false;
      }catch(Exception e){
          e.printStackTrace();
      }
  }

}

我想现在我也应该给你完整的 XML 部分。所以这里是：

  <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:android1="http://schemas.android.com/apk/res/android"
android:id="@+id/containerImg"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android1:layout_gravity="bottom"
android:orientation="vertical"
android1:gravity="bottom" >

    <FrameLayout
    android:id="@+id/frameLayout1"
    android1:layout_width="wrap_content"
    android1:layout_height="wrap_content"
    android:gravity="center|top"
     >

 <SurfaceView
     android1:id="@+id/surfaceView1"
     android1:layout_width="100dip"
     android1:layout_height="150dip"
     android1:layout_gravity="center_horizontal" />

<ImageView
android1:id="@+id/imageView1"
android1:layout_width="fill_parent"
android1:layout_height="fill_parent"
android:contentDescription="@string/app_dress_desc"
android:gravity="center|bottom"
android1:scaleType="center"
android1:src="@drawable/dress" />

</FrameLayout>


<GridLayout
    android1:id="@+id/gridLayout1"
    android1:layout_width="match_parent"
    android1:layout_height="wrap_content"
    android1:layout_alignParentBottom="true"
    android1:layout_alignParentLeft="true"
    android1:columnCount="1"
    android1:gravity="center|bottom"
    android1:orientation="vertical" >

    <ImageButton
        android1:id="@+id/capturebtn"
        android1:layout_width="60dp"
        android1:layout_height="wrap_content"
        android1:layout_gravity="left"
        android1:src="@drawable/camera"
        android:contentDescription="@string/app_icon_camera_desc" />

    <ImageButton
        android1:id="@+id/savebtn"
        android1:layout_width="60dp"
        android1:layout_height="wrap_content"
        android1:layout_column="0"
        android1:layout_gravity="center_horizontal|top"
        android1:layout_row="0"
        android1:src="@drawable/save"
        android:contentDescription="@string/app_icon_save_desc" />

    <ImageButton
        android1:id="@+id/sharebtn"
        android1:layout_width="60dp"
        android1:layout_height="wrap_content"
        android1:layout_column="0"
        android1:layout_gravity="right|top"
        android1:layout_row="0"
        android1:src="@drawable/share"
        android:contentDescription="@string/app_icon_share_desc" />
</GridLayout>

共享按钮此时不起作用，但它会在单击捕获时保存整个框架布局。
希望这会有所帮助。

Answer 6

替代解决方法是将活动 XML 文件与另一个包含标题图像的 XML 文件覆盖。为此：

1. 在布局文件夹中创建一个新的布局文件。例如：
   overlay.xml

2. 在其中插入一个ImageView，例如：

   
   
   <图像视图
       android:id="@+id/imageView1"
       android:layout_centerInParent="true"
       安卓：layout_width =“wrap_content”
       安卓：layout_height =“wrap_content”
       android:src="@drawable/android" />
   
   
   
   

3. 然后在 Activity java 文件中，即 MotionDetector.java 文件，
   创建一个新方法addView()：

    private void addView()
      {
          controlInflater = LayoutInflater.from(getBaseContext());
          View viewControl = controlInflater.inflate(R.layout.overlay, null);
          LayoutParamslayoutParamsControl = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
          this.addContentView(viewControl,layoutParamsControl);
   
      }
   

4. 最后从 onCreate() 调用 addView() 方法来添加图像：

   protected void onCreate(Bundle savingInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.header);
   添加视图（）；
   

然后最终结果将是图像覆盖在 >SurfaceView。根据标题图像的质量，标题的渲染质量应看起来是原始的。希望有帮助。