在其他情况下控制自定义消息

Question

我已经开发了文本框以添加日期范围，以在该日期范围内选择特定记录。如果两个文本框都是空的，我已经写了如果其他内容，则显示错误消息，但是问题是当我首次拨打电话页面时，它显示相同的错误。我知道为什么，因为在第一次尝试中，文本框是空的，但是如何控制它？

public ActionResult ShowMyAtdByDate(String DateFrom, String DateTo) 
    {
        int empId = 0;
        int.TryParse((string)Session["Employee"], out empId); // parse variable to int and saves the result in empId
     //   IEnumerable<GetMyAtd_DateResult> MyAtdRecord = DataContext.GetMyAtd_Date(DateFrom,DateTo,empId).ToList();
        if (DateFrom != "" && DateTo == "" && empId > 0)
        {
            IEnumerable<GetMyAtd_DateResult> MyAtdRecord = DataContext.GetMyAtd_Date(DateFrom,null, empId).ToList();
            ViewBag.Dates = "Records for" + " " + DateFrom;
            return View(MyAtdRecord);
        }
        else if (DateFrom == "" && DateTo != "" && empId > 0)
        {
            IEnumerable<GetMyAtd_DateResult> MyAtdRecord = DataContext.GetMyAtd_Date( null, DateTo, empId).ToList();
            ViewBag.Dates = "Records for" + " " + DateTo;
            return View(MyAtdRecord);
        }
        else if (DateFrom != "" && DateTo != "" && empId > 0)
        {
            IEnumerable<GetMyAtd_DateResult> MyAtdRecord = DataContext.GetMyAtd_Date(DateFrom, DateTo, empId).ToList();
            ViewBag.Dates = "Records from" + " " + DateFrom + " " + "to" + " " + DateTo;
            return View(MyAtdRecord);
        }
        else if (DateFrom == "" && DateTo == "" && empId > 0)
        {
            IEnumerable<GetMyAtd_DateResult> MyAtdRecord = DataContext.GetMyAtd_Date(null, null, empId).ToList();
            ViewBag.Dates = "No dates selection";
            return View(MyAtdRecord);
        }
        else if(empId <=0 )
        {
            return RedirectToAction("IsAuth_Page","Home");
        }
        return View();

    }

查看：

@{
     var grid = new WebGrid(ViewData.Model, rowsPerPage: 25);
 }
 @if (Model.Count > 0)
 {
     <div id="AllMyAtd_ByDate">
       @grid.GetHtml(columns: grid.Columns(
                                        grid.Column("EmplID", "Employee ID"),
                                        grid.Column("EmplName", "Employee Name"),
                                        grid.Column("ShiftID", "Shift ID"),
                                        grid.Column("DateVisited", "Date of Visit"),
                                        grid.Column("InTime", "In Time"),
                                        grid.Column("TimeOut", "Time Out"),
                                        grid.Column("OverTime", "Over Time"),
                                        grid.Column("TotalWorkingTime", "Total Working Time")
                                      ))
     </div>
 }
 else
 {
     <h4 class="error">Sorry Record Doesn't Exist for selected date(s)</h4>  
 }

当我第一次浏览此页面时，这实际上只有在我将两个文本框留为空时才出现。

Answer 1

用户第一次进入此页面时，它将是一个重新要求。您可以从get方法中删除此逻辑（因为它是第一次时不需要执行）并将其放入后方法中，因为这是当时将在用户已提交表格。

---

[HttpGet]
public ActionResult ShowMyAtdByDate()
{
    int empId = 0;
    int.TryParse((string)Session["Employee"], out empId);
    if (empId <= 0)
    {
        return RedirectToAction("IsAuth_Page", "Home");
    }
    return View();
}
[HttpPost]
public ActionResult ShowMyAtdByDate(string dateFrom, string dateTo)
{
    if (dateFrom != "" && dateTo == "" && empId > 0)
    {
        ...
    }
    else if (dateFrom == "" && dateTo != "" && empId > 0)
    {
        ...
    }
    etc...
}

并确保在您的视图中您的表格具有方法post