I have a SQL Server table with several date columns that can be NULL and in fact are NULL . I thought I was handling this correctly by using the .HasValue test before trying for the value of a nullable type. But apparently not because I'm getting an InvalidOperationException - Nullable object must have a value - when the getter in my class object tries to populate a textbox: Public Class
我有一个SQL Server表与几个日期列可以为NULL ，实际上是NULL 。 我以为我正在通过使用.HasValue测试正确处理这个问题，然后尝试可空类型的值。 但显然不是因为我得到一个InvalidOperationException - Nullable对象必须有一个值 - 当我的类对象中的getter试图填充一个文本框时： Public Class EventItem Private _AcknowledgeDate As Nullable(Of Date) Public Property AcknowledgeDate() As Date? Get
Well I am on my last day of school trying to finish a program and I can't for the life of me get past this null reference exception. My code is supposed to average together [count] numbers entered by the user using a stack of Integers. It was throwing a null reference exception because it attempted to get the count of the stack which was empty, so I added the line to Push a zero on to it.
那么我在学校的最后一天试图完成一个程序，我不能为我的生活过去这个空引用异常。 我的代码应该使用整数堆栈来计算用户输入的数字[count]。 它抛出了一个空引用异常，因为它试图获得空的堆栈的计数，所以我添加了一行来推零。 该程序现在停在那条具有相同错误的行（nullreferenceexception）。 如果我改变栈接受字符串，它工作正常，但我需要它接受整数。 感谢任何人可以帮助:) Module Module1 Sub Main() Dim
Given a table Element with a DateTime field birthday (not null), in Entity framework 4 I am allowed to do: Dim mylist = (From el in Element Select el).ToList() .Select(function(el) new with { .bday = el.birthday.toString("dd/MM/yy") } I am now required to change birthday to be nullable, therefore I change the table in SQL server and then update my ModelDB in Visual
给定一个带DateTime字段生日表（不为空）的表元素，在实体框架4中，我可以这样做： Dim mylist = (From el in Element Select el).ToList() .Select(function(el) new with { .bday = el.birthday.toString("dd/MM/yy") } 我现在需要将生日更改为可空，因此我更改了SQL Server中的表格，然后在Visual Studio中更新了我的ModelDB。 结果是该行： .bday = el.birthday.toString("dd/MM
I have an SQL Server table with a view and a smallint field. All data in the view are automatically marked as nullable from Petapoco T4 generator since you can't specifiy it in a view. I'm fine with all the other datatypes so far (guid, int, tinyint, string, etc.) but it seems that the nullable smallint cause some issues. The T4 generator in VB.NET creates this for the SMALLINT field:
我有一个SQL Server表与视图和smallint字段。 由于您无法在视图中指定它，视图中的所有数据都会自动标记为可从Petapoco T4生成器中取消。 到目前为止，我还没有遇到所有其他数据类型（guid，int，tinyint，string等），但似乎可空的smallint会导致一些问题。 VB.NET中的T4生成器为SMALLINT字段创建了以下代码： Private mPasswordResetDays As Integer? <Column> _ Public Property PasswordResetDays() A
I'm a desktop developer writing for internal users, so I'm not worried about malicious hackers, but I would like to know if there's anything they could enter when updating a value that would execute sql on the server. The business defines their content schema and I have a CRUD application for them that doesn't have to be changed when their schema changes because the validation d
我是一个为内部用户撰写的桌面开发人员，所以我不担心恶意黑客，但我想知道在更新可以在服务器上执行sql的值时是否有任何可以输入的内容。 业务定义了他们的内容模式，并且我有一个CRUD应用程序，当他们的模式更改时不需要更改，因为验证详细信息是表驱动的，更新使用动态SQL。 我必须在他们的数据输入中支持单引号，所以当他们输入时，我会在服务器上执行SQL之前将它们加倍。 但是，从我读过的内容来看，这不足以阻止注射。
I'm currently using a homegrown method to run a process as a different user in Vista, and I can't escape the feeling that's it hack-ish and less than ideal (in addition to the fact that it craps out UAC, crashing my app with a security exception, and forcing me to disable UAC altogether). My process consists of two projects (so two EXE files) - an "interface" and a "la
我目前正在使用本地出品的方法在Vista中以不同的用户身份运行进程，但我无法逃避这种黑客行为并不理想的感觉（除了这样一个事实，即它会摧毁UAC，导致我崩溃有安全异常的应用程序，并迫使我完全禁用UAC）。 我的过程由两个项目组成（所以两个EXE文件） - 一个“界面”和一个“启动存根” - 以下是过程： 用户有一个启动“Interface.exe notepad.exe”的快捷方式 Interface.exe具有一个表单，要求输入他们想要使用的凭据 Interac
This question already has an answer here: Deep cloning objects 39 answers Public Sub New(ByVal p_Name As String, ByVal p_Unit As String, ByVal p_Value As Object, ByVal p_Type As String) m_Name = p_Name m_Unit = p_Unit m_Type = p_Type If TypeOf (p_Value) Is Double Then m_Value = p_Value ElseIf TypeOf (p_Value) Is clsVectorParameter Then m_Value = p_Value.Clone() End If End S
这个问题在这里已经有了答案： 深入克隆对象39个答案 Public Sub New(ByVal p_Name As String, ByVal p_Unit As String, ByVal p_Value As Object, ByVal p_Type As String) m_Name = p_Name m_Unit = p_Unit m_Type = p_Type If TypeOf (p_Value) Is Double Then m_Value = p_Value ElseIf TypeOf (p_Value) Is clsVectorParameter Then m_Value = p_Value.Clone() End If End Sub 为了让代码与例如创
My question is basically just how to end the Excel.exe process that runs when using excel. In the application I open and use an excel workbook with a couple sheets, then leave them for the user to do as they please, my problem is that my application never lets go of the Excel process. If the application is closed before closing excel, the process ends when excel is closed, otherwise if I close
我的问题基本上就是如何结束使用Excel时运行的Excel.exe进程。 在应用程序中，我打开并使用一对Excel工作簿，然后让用户按照自己的意愿去做，但问题是我的应用程序从未放弃过程。 如果应用程序在关闭excel之前关闭，则在excel关闭时结束该过程，否则如果在关闭excel后关闭应用程序，则该过程将保持运行。 我已经尝试了一些我在互联网上发现的与GC.collect有关的事情，并等待未决的终结器或者沿着这些线路发生的事情，但是都
This question already has an answer here: String manipulation with & or + in VB.NET 6 answers I've heard good, strong arguments in favor of both operators. Which argument wins the day depends largely on your situation. The one thing I can say is that you should standardize on one or the other. Code that mixes the two is asking for confusion later. The two arguments I remember rig
这个问题在这里已经有了答案： 使用VB.NET 6中的＆或+进行字符串操作的答案 我听到有利于两家运营商的良好而有力的论据。 主要取决于你的情况。 我可以说的一件事是你应该在其中一个标准化。 混合这两者的代码稍后要求混淆。 我记得现在支持＆的两个论点： 如果您没有使用Option Strict并且有两个数字字符串，编译器很容易将您的+运算符的含义与算术添加混淆 如果你正在更新很多旧的vb6代码，它不需要转换连接操作
I'm using devexpress 11.1.4. version also xtraGrid control, my code is vb.net I have set repositoryItemTextEdit to display mask into grid column. I whant to set date format: "dd.mm.yyyy " At the time of typing looks good , however when cells lose focus it changes in format: "mm.dd.yyyy" Also sometimes they just emptied or when i choose for example: 10.05.2015. it
我正在使用devexpress 11.1.4。 版本也xtraGrid控制，我的代码是vb.net我已经设置repositoryItemTextEdit显示掩码到网格列。 我想设置日期格式： “dd.mm.yyyy” 在输入时看起来不错，但是当单元格失去焦点时，它会改变格式：“mm.dd.yyyy” 有时他们只是清空或当我选择例如：10.05.2015。 它改变了它看起来像这样的价值：01.05.2015。 我不知道为什么 这是我的代码： Public dateWithTextEdit As RepositoryItemTe