EditText默认输入数字，且只能输入指定字符

mEditText.setKeyListener(new NumberKeyListener() {                @Override                public int getInputType() {                    // TODO Auto-generated method stub                    return 3;// 默认使用数字键盘                }                @Override                protected char[] getAcceptedChars() {                    // TODO Auto-generated method stub                    char key[] = new char[] { '1', '2', '3', '4', '5', '6','7', '8', '9', '0', 'X' };                    return key;                }            });