public StringAppend(KeyboardViewModel keyboardviewModel)
 {
     this.keyboardviewmodel = keyboardviewModel;
 }
 public StringClear(KeyboardViewModel keyboardviewmodel)
 {
     this.keyboardviewmodel = keyboardviewmodel;
 }
 public PushedShift(KeyboardViewModel keyboardviewModel)
 {
     this.keyboardviewmodel = keyboardviewModel;
 }
 public StringBack(KeyboardViewModel keyboardviewmodel)
 {
     this.keyboardviewmodel = keyboardviewmodel;
 }