选择C＃的WinForms TabControl的元件读取为空，直到TabPage的 [英] C# Winforms TabControl elements reading as empty until TabPage selected

问题描述

我有winform应用程序，我在C＃编写。在我的表，我有七页，每个完整的内容（文本框和DropDownLists，主要是）一个TabControl。我拉在与一个DataReader一些信息，填充数据表，并使用元素的DataBindings.Add方法来填充与电流值的那些元素

I have Winform app I am writing in C#. On my form, I have a TabControl with seven pages, each full of elements (TextBoxes and DropDownLists, primarily). I pull some information in with a DataReader, populate a DataTable, and use the elements' DataBindings.Add method to fill those elements with the current values.

用户能够将数据输入到这些因素，按保存，然后我将用元素的文本字段的UPDATE查询的参数。例如：

The user is able to enter data into these elements, press "Save", and I then set the parameters of an UPDATE query using the elements' Text fields. For instance:

updateCommand.Parameters.Add("@CustomerName", SqlDbType.VarChar, 100).Value = CustomerName.Text;

我的问题是，一旦我加载的形式，所有的元素都显然认为是空的，直到我手动选择的每个选项卡。因此，如果我按保存后立即加载的形式，所有的字段上，我还没有尝试选择空数据来更新（不是很好）的的TabPages。当我选择每个TabPage的，这些元素会沿着现在正确地发送它们的数据。从目前来看，我已经摸索出了（非常）丑陋的解决办法，我以编程方式选择每个TabPage的当数据被填充的第一次，但是这是无法接受的长期解决方案。

The problem I have is that once I load the form, all of the elements are apparently considered empty until I select each tab manually. Thus, if I press "Save" immediately upon loading the form, all of the fields on the TabPages that I have not yet selected try to UPDATE with empty data (not nice). As I select each TabPage, those elements will now send their data along properly. For the time being, I've worked out a (very) ugly workaround where I programmatically select each TabPage when the data is populated for the first time, but that's an unacceptable long-term solution.

我的问题是，我怎么能得到所有的的TabPages元素返回其数据的用户选择之前正确的TabPage的？

My question is, how can I get all of the elements on the TabPages to return their data properly before the user selects that TabPage?

推荐答案

浩是正确的;直到选择了TabPage的不创建一个TabPage的元素。我只是说在它选择的每个TabPage的，现在它工作正常形式的负载循环。

ho is correct; the elements on a TabPage are not created until that TabPage is selected. I just added a loop upon form load that selects each TabPage and now it works fine.

foreach (TabPage tp in tabControl1.TabPages)
    {
        page.Show();
    }

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