最近做了一个Android系统的收银机项目，用的设备是方派的，用户提供二维码或者条形码，放到设备的右下角扫码器那里扫码，现在记录一下获取扫码内容的方法。
1. 先重写Activity的onKeyDown方法，收集keycode。
private List scannedCodes = new ArrayList<>();
private StringBuilder scanBuilder = new StringBuilder(); //拼接字符
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode != KeyEvent.KEYCODE_ENTER) {//扫码枪以回车为结束
scannedCodes.add(keyCode);
}else {
//结束
handleKeyCodes();
}
return super.onKeyDown(keyCode, event);
}
2. 处理keycodes。
private void handleKeyCodes() {
boolean hasShift =false;
for (int keyCode :scannedCodes) {
scanBuilder.append(DataBinder.keyCodeToChar(keyCode, hasShift));
hasShift = (keyCode == KeyEvent.KEYCODE_SHIFT_LEFT);
}
//获取扫码内容
String code = scanBuilder.toString();
scanBuilder.setLength(0);
scannedCodes.clear();
}
3. 将keycode转换为字符。
/**
* keyCode转换为字符
*/
public static String keyCodeToChar(int code, boolean isShift) {
switch (code) {
case KeyEvent.KEYCODE_SHIFT_LEFT:
return "";
//数字键10个 + 符号10个
case KeyEvent.KEYCODE_0:
return isShift ?")" :"0";
case KeyEvent.KEYCODE_1:
return isShift ?"!" :"1";
case KeyEvent.KEYCODE_2:
return isShift ?"@" :"2";
case KeyEvent.KEYCODE_3:
return isShift ?"#" :"3";
case KeyEvent.KEYCODE_4:
return isShift ?"$" :"4";
case KeyEvent.KEYCODE_5:
return isShift ?"%" :"5";
case KeyEvent.KEYCODE_6:
return isShift ?"^" :"6";
case KeyEvent.KEYCODE_7:
return isShift ?"&" :"7";
case KeyEvent.KEYCODE_8:
return isShift ?"*" :"8";
case KeyEvent.KEYCODE_9:
return isShift ?"(" :"9";
//字母键26个小写 + 26个大写
case KeyEvent.KEYCODE_A:
return isShift ?"A" :"a";
case KeyEvent.KEYCODE_B:
return isShift ?"B" :"b";
case KeyEvent.KEYCODE_C:
return isShift ?"C" :"c";
case KeyEvent.KEYCODE_D:
return isShift ?"D" :"d";
case KeyEvent.KEYCODE_E:
return isShift ?"E" :"e";
case KeyEvent.KEYCODE_F:
return isShift ?"F" :"f";
case KeyEvent.KEYCODE_G:
return isShift ?"G" :"g";
case KeyEvent.KEYCODE_H:
return isShift ?"H" :"h";
case KeyEvent.KEYCODE_I:
return isShift ?"I" :"i";
case KeyEvent.KEYCODE_J:
return isShift ?"J" :"j";
case KeyEvent.KEYCODE_K:
return isShift ?"K" :"k";
case KeyEvent.KEYCODE_L:
return isShift ?"L" :"l";
case KeyEvent.KEYCODE_M:
return isShift ?"M" :"m";
case KeyEvent.KEYCODE_N:
return isShift ?"N" :"n";
case KeyEvent.KEYCODE_O:
return isShift ?"O" :"o";
case KeyEvent.KEYCODE_P:
return isShift ?"P" :"p";
case KeyEvent.KEYCODE_Q:
return isShift ?"Q" :"q";
case KeyEvent.KEYCODE_R:
return isShift ?"R" :"r";
case KeyEvent.KEYCODE_S:
return isShift ?"S" :"s";
case KeyEvent.KEYCODE_T:
return isShift ?"T" :"t";
case KeyEvent.KEYCODE_U:
return isShift ?"U" :"u";
case KeyEvent.KEYCODE_V:
return isShift ?"V" :"v";
case KeyEvent.KEYCODE_W:
return isShift ?"W" :"w";
case KeyEvent.KEYCODE_X:
return isShift ?"X" :"x";
case KeyEvent.KEYCODE_Y:
return isShift ?"Y" :"y";
case KeyEvent.KEYCODE_Z:
return isShift ?"Z" :"z";
//符号键11个 + 11个
case KeyEvent.KEYCODE_COMMA:
return isShift ?"<" :",";
case KeyEvent.KEYCODE_PERIOD:
return isShift ?">" :".";
case KeyEvent.KEYCODE_SLASH:
return isShift ?"?" :"/";
case KeyEvent.KEYCODE_BACKSLASH:
return isShift ?"|" :"\\";
case KeyEvent.KEYCODE_APOSTROPHE:
return isShift ?"\"" :"'";
case KeyEvent.KEYCODE_SEMICOLON:
return isShift ?":" :";";
case KeyEvent.KEYCODE_LEFT_BRACKET:
return isShift ?"{" :"[";
case KeyEvent.KEYCODE_RIGHT_BRACKET:
return isShift ?"}" :"]";
case KeyEvent.KEYCODE_GRAVE:
return isShift ?"~" :"`";
case KeyEvent.KEYCODE_EQUALS:
return isShift ?"+" :"=";
case KeyEvent.KEYCODE_MINUS:
return isShift ?"_" :"-";
default:
return "?";
}
}
4. 扫码可能会碰到的问题。
扫码时触发了其他控件的点击事件，解决办法是在Activity的最外层布局上加入：
android:focusable="true"
android:focusableInTouchMode="true"
问题可解决。
