Android实现读取扫码枪内容(条形码)

近期有个需求，安卓设备外接扫码枪，系统读取扫码枪扫描的内容。

网上查了一些例子，拿过来用的时候都不太好使，最后没办法，自己实现了一个（目前只支持英文字母和英文符号）。

代码如下：

1. 重写Activity的onKeyDown方法，收集扫码枪返回的keycode。

ArrayList<Integer> scannedCodes = new ArrayList<Integer>();

@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. 处理接收倒的keycode，handleKeyCodes()方法。

private void handleKeyCodes(){
 FnString fnString = new FnString();
 String result = "";
 boolean hasShift = false;
 for(int keyCode : scannedCodes){
  result += fnString.keyCodeToChar(keyCode, hasShift);
  hasShift = (keyCode == KeyEvent.KEYCODE_SHIFT_LEFT);
 }
 Toast.makeText(context, result, Toast.LENGTH_LONG).show();
 scannedCodes.clear();
}

3. keycode转换为字符的方法

/** keyCode转换为字符 */
public 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 "?";
 }
}

效果1：

效果2：

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