js方法收藏

1.验证非负数字

//onfocusout="checkQty(this);"

function checkQty(obj) {
    //排除0开头的非法输入
    if (obj.value.length >= 2) {
        var a = obj.value.charAt(0);
        var b = obj.value.charAt(1);
        if (a == '0' && b != '.') {
            obj.value = '0';
            alert('请输入正确的数字格式！');
            return;
        }
    }

    //数字验证
    var regExp = new RegExp(/^\d+(\.\d+)?$/);
    var result = regExp.test(obj.value);
    if (!result) {
        obj.value = '0';
        alert('请输入正确的数字格式！');
    }
}

 2.select动态绑定，选中

$.ajax({
    type: "POST",
    url: "../loadjsonM/PrinterTemplate_JhJson.ashx",
    async: false,
    data: { uptype: 3 },
    success: function (data) {
        if (data != '') {
            var printNames = data.toString().split(',');
            if (printNames != undefined && printNames.length > 0) {
                var searchtp = $("#printForm [name='printer']").get(0);
                searchtp.options.length = 0;
                for (var i = 0; i < printNames.length; i++) {
                    var nowarr = printNames[i];
                    searchtp.options.add(new Option(nowarr.toString(), nowarr.toString()));
                }
            }
        }
    }
});

$.post("../loadjsonM/printLog_JhJson.ashx", { uptype: 0 },
    function (data) {
        var back_json;
        eval(data);
        if (back_json.length == 1) {
            var printer = $("#printForm [name='printer']").get(0);
            var barcodeModel = $("#printForm [name='barcodeModel']").get(0);

            for (var i = 0; i < printer.options.length; i++) {
                if (printer.options[i].text == back_json[0].Printer) {
                    printer.options[i].selected = 'selected';
                }
            }

            for (var i = 0; i < barcodeModel.options.length; i++) {
                if (barcodeModel.options[i].text == back_json[0].BarcodeModel) {
                    barcodeModel.options[i].selected = 'selected';
                }
            }
        }
    }
);

 3.扫描枪一般处理脚本

$("#searthtxt").keydown(function (event) {
     if (event.keyCode == 13) {
         $("#searchbtn").click();
         $("#searthtxt").select();
     }
 });

 3.Js判断是否为空

var exp = null;
if (!exp && typeof(exp)!="undefined" && exp!=0)
{
    alert("is null");
}