Question

如何验证用户仅输入字符串或整数值或三个特殊字符（@和$）或它们的组合的EditText输入？

其他输入必须显示错误。

这是我的代码。

public static boolean Check_input_validation(String input){
if(!input.matches("^[a-zA-Z0-9]*$"))
    return false;
else
    return true;
}

Answer 1

为EditText创建一个过滤器，并在过滤器中定义条件。例如，仅接受数字

    final String[] acceptLtrs = {"1", "2", "3", "4", "5", "6", "7", "8", "9", "0"};
        InputFilter filter = new InputFilter() {
            public CharSequence filter(CharSequence source, int start, int end,
                                       Spanned dest, int dstart, int dend) {

             if (source.toString().isEmpty()) return null;
                for (String acceptLtr : acceptLtrs) {
                    if (source.equals(acceptLtr)) {
                        return null; // will accept input
                    }
                }

             return ""; // will dismiss the input or you can show error here

}};

然后edittext.setFilters(new InputFilter[]{filter});

Answer 2

使用regexp和TextChangedListener进行验证

EditText.addTextChangedListener(new TextWatcher() {
    // ...
    @Override
    public void onTextChanged(CharSequence text, int start, int count, int after) {
       validate(text.toString())
       // your condition
    }
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, 
                                  int after) {
        // TODO Auto-generated method stub
    }

    @Override
    public void afterTextChanged(Editable s) {

    }
});



public boolean validate(String str){
    Pattern pattern;
    Matcher matcher;
    final String PATTERN = "[a-zA-Z0-9\-@#$]";
    pattern = Pattern.compile(PATTERN);
    matcher = pattern.matcher(str);

    return matcher.matches();
  }

在Android中使用允许的字符验证EditText输入

2 个答案: