How to Use Q1 Buttons in Applications: Difference between revisions
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The others are digital buttons which are defined in the Android system. See android.view.KeyEvent. | The others are digital buttons which are defined in the Android system. See android.view.KeyEvent. | ||
== Scan button and QR Code button | == Scan button and QR Code button == | ||
The scan button and QR code button can quickly launch the scan application. If you press one of the buttons, the system will search for all the applications installed in the system and will launch the application with the scan intent-filter. If there are many applications, the system will provide a list for users to choose, and the selected application will start. The code for the scan intent-filter is as follows: | |||
The | |||
<action android:name="android.intent.action.SCAN" /> | <action android:name="android.intent.action.SCAN" /> | ||
<category android:name="android.intent.category.DEFAULT" /> | <category android:name="android.intent.category.DEFAULT" /> | ||
When there is no application in the system to define the scan intent-filter, pressing the scan button or QR code button will not work. | |||
=== Sample === | === Sample === | ||
There are two ways to use the Scanner Key and the QRCode Key: | There are two ways to use the Scanner Key and the QRCode Key: |
Revision as of 04:11, 26 March 2020
Keyboard description
Key | Value | Description |
---|---|---|
Period | KeyEvent.KEYCODE_PERIOD | The black dot button on the right-bottom of keyboard. |
QRCode | 232 | The orange button on the middle-bottom of keyboard |
Back | KeyEvent.KEYCODE_ESCAPE | The red X button on the left-bottom of keyboard |
Scann | 229 | The orange button on the left of the LED |
Delete | KeyEvent.KEYCODE_DEL | The yellow triangle button on the right-top of keyboard |
Enter | KeyEvent.KEYCODE_ENTER | The green circle button on the right-bottom of keyboard |
The others are digital buttons which are defined in the Android system. See android.view.KeyEvent.
Scan button and QR Code button
The scan button and QR code button can quickly launch the scan application. If you press one of the buttons, the system will search for all the applications installed in the system and will launch the application with the scan intent-filter. If there are many applications, the system will provide a list for users to choose, and the selected application will start. The code for the scan intent-filter is as follows:
<action android:name="android.intent.action.SCAN" /> <category android:name="android.intent.category.DEFAULT" />
When there is no application in the system to define the scan intent-filter, pressing the scan button or QR code button will not work.
Sample
There are two ways to use the Scanner Key and the QRCode Key:
- To start scanner application quickly. The application must define the intent-filter of scanner in its’ android manifest file, the category and the action definition are as below:
<activity android:name="com.XX.activity.MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.SCAN" /> <category android:name="android.intent.category.DEFAULT" /> </intent-filter> </activity>
- Use like the other keys, when press the key , the activated and top task will get the key value and do as its logic source code. Firstly the application must override the function of onKeydown, as follows:
/** Key code constant: left scan key. */
public static final int KEYCODE_SCAN_LEFT = 229;
/** Key code constant: right scan key. */
public static final int KEYCODE_SCAN_RIGHT = 230;
/** Key code constant: qr key. */
public static final int KEYCODE_QR = 232;
public boolean onKeyDown(int keyCode, KeyEvent event) {
// listen the key code
if (keyCode == KEYCODE_SCAN_LEFT|| keyCode ==KEYCODE_SCAN_RIGHT|| keyCode ==KEYCODE_QR) {
//do something, for example:scanner……
return true;
}
return super.onKeyDown(keyCode, event);
}