小编She*_* GM的帖子

我目前正在开发一种扫描仪,可以读取一张图像中的多个QR码.我设法读取图像中的QR码,但它给了我不一致的结果.假设图像中有4个QR码,有时我可以读取2个,有时3个或仅1个.与原始扫描仪(ZXing扫描仪)不同,它可以快速解码.在我的情况下,我必须确保有足够的光线,图像不会模糊解码.

我正在使用它QRCodeMultiReader来解码图像.目前正在使用ZXingLibrary来创建应用程序.

以下是我的代码片段:

public void onPictureTaken(byte[] data, Camera camera) {
   BitmapFactory.Options opt = new BitmapFactory.Options();
    opt.inMutable = true;
   Bitmap bitmap = BitmapFactory
            .decodeByteArray(data, 0, data.length, opt);
   Hashtable<DecodeHintType, Object> hints = new Hashtable<DecodeHintType, Object>();
   hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
   LuminanceSource source = new RGBLuminanceSource(bitmap);

   QRCodeMultiReader multiReader = new QRCodeMultiReader();
   Result[] results = multiReader.decodeMultiple(new BinaryBitmap(
   new HybridBinarizer(source)), hints);
}

我想以编程方式获取主屏幕启动器中所有已安装快捷方式的列表.我在网上找到了很多片段,但没有一个提供正确的输出

对于此片段:

Intent shortcutsIntent = new Intent(Intent.ACTION_CREATE_SHORTCUT);
ArrayList<Intent> intentList = new ArrayList<Intent>();
Intent intent=null;
String launchers="";
final PackageManager packageManager=getPackageManager();
for(final ResolveInfo resolveInfo:packageManager.queryIntentActivities(shortcutsIntent,   0)) {
launchers=launchers+"\n"+resolveInfo.activityInfo.packageName;
intent=packageManager
         .getLaunchIntentForPackage(resolveInfo.activityInfo.packageName);
intentList.add(intent);    
}

这只提供联系人,浏览器等预设快捷方式.不完全是在主屏幕上找到的.

而这个片段:

    PackageManager pm = getPackageManager();
    Intent i = new Intent("android.intent.action.MAIN");
    i.addCategory("android.intent.category.HOME");
    List<ResolveInfo> lst = pm.queryIntentActivities(i, 0);
    if (lst != null) {
       for (ResolveInfo resolveInfo : lst) {  
           }
       }
    }

仅提供com.android.launcher的默认启动器.

我想创建类似上面的东西,这三个盒子,就像一个相机预览.关于该怎么做的任何想法或概念？

我尝试获取相机的实例并将其放置到三个camerapreview对象,但我收到一条错误消息,我想,这是不允许的.这是我的代码:

  private CameraPreview mPreview;
  private CameraPreview mPreview2;
  private CameraPreview mPreview3;
  private FrameLayout preview;
  private FrameLayout preview2;
  private FrameLayout preview3;

    mCamera=getCameraInstance(); 
    mCamera2=getCameraInstance();
    mCamera3=getCameraInstance();

    mPreview=new CameraPreview(getApplicationContext(), mCamera);
    mPreview2=new CameraPreview(getApplicationContext(), mCamera2);
    mPreview3=new CameraPreview(getApplicationContext(), mCamera3);

    preview=(FrameLayout)findViewById(R.id.camSetA_qr1);
    preview.addView(mPreview);
    preview2=(FrameLayout)findViewById(R.id.camSetA_qr1);
    preview2.addView(mPreview2);
    preview3=(FrameLayout)findViewById(R.id.camSetA_qr1);
    preview3.addView(mPreview3);

和我的getinstance代码

 public static Camera getCameraInstance() {
    Camera c = null;
    try {
        c = Camera.open();
    } catch (Exception e) {
    }
    return c;
 }