kevinya

textbox的html:

<input type="text" class="form-control" id="txtAchieveStartDate" value="" onkeypress="return isNumber(event,'txtAchieveStartDate')" placeholder="格式YYYMM 202201">

javascript:

function isNumber(evt, objId) {
    evt = (evt) ? evt : window.event;
    var charCode = (evt.which) ? evt.which : evt.keyCode;
    if (charCode > 31 && (charCode < 48 || charCode > 57)) {
        return false;
    }
    if ($('#' + objId).val().length >= 6) {
        return false;
    }
    return true;
}

 

這篇大概是這樣～

ps.20230505補充：以下寫法可限定textbox只可以輸入浮點數
html + javascript：

<script type="text/javascript" >
	$(document).ready(function () {
        //float number only
        $('input.float').on('input', function () {
            this.value = this.value.replace(/[^0-9.]/g, '').replace(/(\..*?)\..*/g, '$1');
        });
    });
	
	
</script>

<input type="text" class="form-control float" id="txtWeightKG" value="50" placeholder="請輸入數字">

 

 

參考資料：
工作經驗
allowing input only for float number
https://stackoverflow.com/questions/10150877/allowing-input-only-for-float-number