Introduction to two-dimensional Code fast scanning optimization scheme (i.)--How to automatically fill the light when the light is low.

QR Code Scan Code is a very common technology, there are many open source projects can be implemented, such as Zxing project. Https://github.com/zxing

Here is not the focus of the introduction of zxing in the implementation of the QR Code scan code, but to introduce, on the Fast Scan code technology is how to optimize the experience.

To achieve in the light, the phone automatically fill the light, actually very simple, everyone knows that there are many sensors on the phone, one of the most important sensor is the light sensor.

This is usually used when you take pictures. So how to apply this to the QR code of the sweep code experience up.

We can use the cell phone's light sensor for external light sensing, so when the light is dark, we can automatically fill the light. Here we take the example of Android phone, to explain

On an Android phone, we define a button and a textview,textview to display the intensity index of light received from the light sensor. Button buttons are used when the light is weak to automatically come out of this button, you can click on the phone to open the flash. When the light is strong, the button is automatically hidden.

<?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" >
.......

<button
    Android:layout_width= "Wrap_content"
    android:layout_height= "Wrap_content"
    android:text= "Fill Light"
    Android:id= "@+id/flashlightbutton"
    Android:layout_centervertical= "true"
    Android:layout_centerhorizontal= "true"/>

<textview
    Android:layout_width= "Wrap_content"
    android:layout_height= "Wrap_content"
    Android:id= "@+id/ligthsensorview"
    android:layout_below= "@+id/flashlightbutton"
    Android:layout_centerhorizontal= "true"
    android:layout_margintop= "92DP"/>

</RelativeLayout>
</FrameLayout>
In the activity, we define the buttons and TextView above
Fill Light button

Private Button Flashlightbutton;
Shows the current light intensity

Private TextView Ligthsensorview;
Light sensor related

Private Sensormanager SM;
Private Sensor ligthsensor;

Flashlightbutton  = (Button) Findviewbyid (R.id.flashlightbutton);
Ligthsensorview = (TextView) Findviewbyid (R.id.ligthsensorview);
Light sensor Use Registration

SM = (Sensormanager) getsystemservice (Sensor_service);
Ligthsensor = Sm.getdefaultsensor (sensor.type_light);
Sm.registerlistener (New Mysensorlistener (), Ligthsensor, sensormanager.sensor_delay_normal);
Set Button Listener

Flashlightbutton.setonclicklistener (New Flashlightlistener ());

Monitoring implementation of Flashlightbutton

Class Flashlightlistener implements view.onclicklistener{
Boolean isopen = false;
   @Override
   public void OnClick (view view) {
      if (isopen) {
Turn Off the lights
         Cameramanager.get (). Closeflashlight ();
         IsOpen = false;
      }
      else{
Turn on the light
         Cameramanager.get (). Openflashlight ();
         IsOpen = true;
      }
   }
}
Sensor monitoring

public class Mysensorlistener implements Sensoreventlistener {

   public void onaccuracychanged (sensor sensor, int accuracy) {

   }

Get the intensity of the light

public void Onsensorchanged (Sensorevent event) {
      Get precision
      float acc = event.accuracy;
      Get light intensity
      Float lux = event.values[0];
      SB = "Accuracy:" +acc+ ", light intensity:" +lux+ "camera mode:";
Light intensity displayed on the Ligthsensorview

      Ligthsensorview.settext (SB);
      int retval = Float.compare (Lux, (Float) 10.0);
      if (retval>0) {
Light Intensity >10.0 Hide button
         Flashlightbutton.setvisibility (view.invisible);
      }
      else {
Show button
         Flashlightbutton.setvisibility (view.visible);
      }
   }
}

//Turn on the flash by camera 
 public static void Turnlightoncamera (camera mcamera) {
 Mcamera.startpreview (); 
 Camera.parameters Parameters = Mcamera.getparameters (); 
 List<string> flashmodes = Parameters.getsupportedflashmodes (); 
 String Flashmode = Parameters.getflashmode (); 
 if (! Camera.Parameters.FLASH_MODE_TORCH.equals (Flashmode)) {
//turn on Flash 
 if (Flashmodes.contains (Camera.para Meters.            Flash_mode_torch) {
 Parameters.setflashmode (Camera.Parameters.FLASH_MODE_TORCH); 
 Mcamera.setparameters (parameters); 
 Mcamera.startpreview (); 
 Isopenflash = true; 
} 
} 
} 

Turn off the flash by camera
public static void Turnlightoffcamera (Camera mcamera) {
    Mcamera.stoppreview ();
    Camera.parameters Parameters = Mcamera.getparameters ();
    list<string> flashmodes = Parameters.getsupportedflashmodes ();
    String Flashmode = Parameters.getflashmode ();
    if (! Camera.Parameters.FLASH_MODE_OFF.equals (Flashmode)) {
        Turn off the Flash
        if (Flashmodes.contains (Camera.Parameters.FLASH_MODE_OFF)) {
            Parameters.setflashmode (Camera.Parameters.FLASH_MODE_OFF);
            Mcamera.setparameters (parameters);
        }
    }
    Isopenflash = false;
}

Complete the above optimization, then we sweep the code will have a further experience optimization, depending on the intensity of the light to determine whether the need to scan code, to fill the light.

Introduction to two-dimensional Code fast scanning optimization scheme (i.)--How to automatically fill the light when the light is low.