/**
         * 只能输入字母和数字，默认弹出英文输入法
         */
        editext.setKeyListener(new DigitsKeyListener() {
            @Override
            public int getInputType() {
                return InputType.TYPE_TEXT_VARIATION_PASSWORD;
            }
            @Override
            protected char[] getAcceptedChars() {
                char[] data = getStringData(R.string.wordAndNum).toCharArray();
                return data;
            }
        });

   public String getStringData(int id) {
        return getResources().getString(id);
    }

String.xml
 <string name="wordAndNum">qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPLKJHGFDSAZXCVBNM1234567890</string>

android 安卓editext默认弹出英文输入法，只能输入英文与数字