android-edit只能输入汉字字母数字

edZhengshu.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            // 只能输入汉字数字字母
            String editable =
                    edZhengshu.getText().toString();
            String str = stringFilter(editable.toString());
            if (!editable.equals(str)) {
                edZhengshu.setText(str);

//设置新的光标所在位置
edZhengshu.setSelection(str.length());
}
}

        @Override
        public void afterTextChanged(Editable s) {

        }
    });
}