Question

我对editText中的限制号有疑问。我想用户只能写1-30的号码。当用户想要放32时我想阻止这种可能性。我想检查一下用户是否先输入第一个数字4我会阻止输入更多数字。当第一个数字3时，我想阻止除0以外的所有nubmers。我该怎么做？我使用textWatcher来观看文字，但是如何阻止键盘？

Answer 1

试试这种方式

    InputFilter filter = new InputFilter() {

        @Override
        public CharSequence filter(CharSequence source, int start, int end,
                Spanned dest, int dstart, int dend) {
            int num = 0;
            try {
                num = Integer.parseInt(dest.toString()+source.toString());
                if (!(num > 0 && num <= 30)) {
                    return "";
                }
            } catch (Exception e) {
                return "";
            }

            return null;
        }
    };

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

Answer 2

我做了同样的事情：

editListenPort.addTextChangedListener(new TextWatcher(){
    /** Not implemented */
    @Override
    public void afterTextChanged(Editable arg0) { }
    /** Not implemented */
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) { }
    /** After text has been entered into the EditText, this updates the TextView 
     * next to it with the new value. A sanity check is performed if there is no 
     * text entered at all, upon which the listen port is set to 0. */
    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        int numberOfChars = s.length();
        if(numberOfChars > 0){
            mOwnPort = Integer.parseInt(s.toString());
        } else if(numberOfChars <= 0){
            mOwnPort = 0;
        }
        ((TextView) findViewById(R.id.labelOwnIpData)).setText("Own IP-endpoint:\n" + mOwnIp + ":" + mOwnPort);
    }
});

使用这段代码，我检查EditText的输入并更新直接位于EditText旁边的TextView。

虽然如果你更新EditText本身或发出警告，我认为这不是问题。

在android中阻止编号和限制编辑文本

2 个答案: