添加一个用户控件的网页编程，而preserving控制已经present [英] Adding a user control to a page programatically while preserving controls already present

问题描述

我想在运行时添加用户控件到一个div。我可以添加控件没有probelem但它覆盖previous控制补充说。

I am trying to add a user control into a div at runtime. I can add the control no probelem but it overwrites the previous control added.

基本上，我想乘客添加到行驶系统 - 乘客细节都在用户的控制和我事先不知道有多少会出现。我有一个新的添加按钮的乘客应追加新的用户控件到格但不覆盖previous乘客。

Basically, I am trying to add passengers to a travel system - the passenger details are in the user control and I don't know in advance how many there will be. I have an add new passenger button which should append the new user control into the div without overwriting the previous passenger.

在code是C＃/。NET 4.

The code is c#/.net 4.

我试图挽救控制数据到视图状态，并重新用新的补充，但也不能正常工作。下面是我使用的code的片段

I have tried to save the control data into viewstate and re add it with the new one but that also doesn't work. Here is a snippet of the code I'm using

foreach (Control uc in p_passengers.Controls) {
        Passenger p = uc as Passenger;
        if (p != null) {
            p.SaveValues();            
        }
    }

不过，p.SaveAs（）（刚写的控制值到ViewState中）是从不打。

however, p.SaveAs() (just writes the control values into ViewState) is never hit.

我敢肯定，它只是一些愚蠢的事，但任何想法??

Im sure its just something stupid but any ideas??

干杯家伙。

推荐答案

您重新创建所有你的每一个回发动态控件？

记住每次回发是Page类，你pviously创建需要$ P $显式地重新创建任何控件的新实例。

Remember each postback is a new instance of the Page class and any controls you previously created will need to be explicitly re-created.

更新

如果你不得不在ViewState中添加的项目列表，像这样..

If you had a list of added items in viewstate, something like this..

    private List<string> Items
    {
         get
         {
              return ViewState["Items"] = (ViewState["Items"] ?? new List<string>());
         }
    }

然后在你的单击处理程序，你可以简单地添加到这个列表：

Then in your click handler you could simply add to this list :

   private void btn_Click(object sender, EventArgs e)
   {
        this.Items.Add("Another Item");
   }

然后重写的CreateChildControls

  protected overrides CreateChildControls()
  {
       foreach (string item in this.Items)
       {
            Passanger p = new Passenger();
            p.Something = item;
            this.p_passengers.Controls.Add(p);
       }
  }

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