[英]Read custom user control state
I add a custom user control to my page, with textboxes and radioboxes, but after each postback, the contents are removed and I don't know how to read the values that were entered in it. 我添加了一个自定义用户控件到我的页面,文本框和radioboxes,但每次回发后,内容被删除,我不知道如何读取其中输入的值。
From what I've learned you have to add the user controls on each refresh, but that does not restore their state. 根据我的经验,您必须在每次刷新时添加用户控件,但这不会恢复其状态。 I want the values to be stored in the ViewState but that does not happen for some reason.
我希望将值存储在ViewState中,但由于某种原因不会发生这种情况。
Note: I need to add multiple user controls on one page, so I need to identify each user control, either trough an ID or a linq expression that selects that user control from my page. 注意:我需要在一个页面上添加多个用户控件,因此我需要通过ID或从我的页面中选择该用户控件的linq表达式来标识每个用户控件。
Im programming with C# 4.0 我用C#4.0编程
How I add my user control: 我如何添加我的用户控件:
private void AddInstrumentDetailToPage()
{
RMAItem lItem = (RMAItem)Page.LoadControl("/Controls/RMAItem.ascx");
InstrumentDetail.Controls.Add(lItem);
}
I save the amount of controls I have in the ViewState, and call AddInstrumentDetail() that amount of times, but they appear to be empty. 我保存了ViewState中的控件数量,并调用了AddInstrumentDetail()那么多次,但它们看起来都是空的。 I've read somewhere that I have to add it in Page_Init because view state is not initialised yet, but that doesn't help either.
我已经读过某个地方,我必须在Page_Init中添加它,因为视图状态尚未初始化,但这也无济于事。
You need to recreate dynamically added (User-)Controls at latest in Page_Load
to maintain ViewState. 您需要最近在
Page_Load
重新创建动态添加的(用户)控件以维护ViewState。 So you should store the number of already added controls in a ViewState-Property and according to that reload them in Page_Load
. 因此,您应该将已添加的控件的数量存储在ViewState-Property中,并根据它在
Page_Load
中重新加载它们。 You have to sum up this variable with 1 in AddInstrumentDetailToPage
. 您必须在
AddInstrumentDetailToPage
将此变量与1 AddInstrumentDetailToPage
。
MSDN: Dynamically Adding User Controls MSDN:动态添加用户控件
If you store the number of added controls in a Viewstate variable, you cannot recreate controls in Page's Init-Event because the ViewState-Variable would yet not been reloaded there. 如果在Viewstate变量中存储已添加控件的数量,则无法在Page的Init-Event中重新创建控件,因为ViewState-Variable尚未在那里重新加载。
You won't have any ControlState
unless you make a PostBack
. 除非您进行
PostBack
否则您将没有任何ControlState
。 Refreshing your browser/requesting the same link will just be a fresh start. 刷新浏览器/请求相同的链接将是一个全新的开始。
By default, any control
added to your page are data stored in ViewState
and ControlState
for your UserControl
. 默认情况下,添加到页面的任何
control
都是存储在UserControl
ViewState
和ControlState
中的数据。
If you are willing to save your contents, I would suggest you save it on Request.Session.Add("yourKey", "yourValue")
. 如果您愿意保存您的内容,我建议您将其保存在
Request.Session.Add("yourKey", "yourValue")
。
You can access your session with var yourValue = Request.Session["yourKey"];
您可以使用
var yourValue = Request.Session["yourKey"];
访问您的会话var yourValue = Request.Session["yourKey"];
on your protected void Page_Load(object sender, EventArgs e)
method. 在
protected void Page_Load(object sender, EventArgs e)
方法上。
Specify an ID for your RMAItem
instance, otherwise storing data on ControlState
might not work! 指定
RMAItem
实例的ID,否则在ControlState
上存储数据可能不起作用!
private void AddInstrumentDetailToPage()
{
RMAItem lItem = (RMAItem)Page.LoadControl("/Controls/RMAItem.ascx");
lItem.ID = "rmaItem1"; //<-- This is important
InstrumentDetail.Controls.Add(lItem);
}
Hope it helps! 希望能帮助到你!
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