当我不检查复选框。

问题描述

您好，先生，

我对checkboxlist有疑问。我面临错误长度不能小于零。参数名称：长度。我的代码是

Hello sir,
I have aproblem with checkboxlist.I am facing the error " Length cannot be less than zero. Parameter name: length ".My code is

string chkIncludeWithsalary = "";
            foreach (ListItem lst in chkIncludedWithSalary.Items)
            {
                if (lst.Selected)
                    chkIncludeWithsalary += lst.Text + ",";
            }

            chkIncludeWithsalary = chkIncludeWithsalary.Substring(0, (chkIncludeWithsalary.Length - 1));

如果我没有检查任何ckeckbox。

If i am not checking any ckeckbox.

推荐答案

PreRenderComplete()

或

Page_Load()

或

Page_Init()

以上说明适用于下拉列表，复选框列表，单选按钮列表等。

Above said is applicable for dropdownlist, checkboxlist, radiobutton lists etc..

chkIncludeWithsalary.Substring(0, (chkIncludeWithsalary.Length - 1));

子串参数为：startPosition，NoOfCharacters - 两者都必须为0或者以上，不能为负数。



根据错误和我看到的代码，看起来第二个参数是负值，因此错误。

（chkIncludeWithsalary.Length - 1） - >是负数，这意味着 chkIncludeWithsalary 中没有值 - 它是空的。



你需要制作确保字符串中有一些东西 chkIncludeWithsalary 。根据代码，只要复选框列表中没有选择，您就会收到此错误。处理它。

Substring parameters are: startPosition, NoOfCharacters - both has to be 0 or above, cannot be negative.

Based on error and the code I see, it looks like second parameter is a negative value and hence the error.
(chkIncludeWithsalary.Length - 1) -> is negative, which means that there was no value in chkIncludeWithsalary - it was empty.

You need to make sure that there is something in the string chkIncludeWithsalary . Based on the code, you will get this error whenever there is no selection in the checkboxlist. Handle it.

这篇关于当我不检查复选框。的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！