ASP 中用于从用户控件到父页面的通信的技术是什么？

Question

我在从用户控件到主页的通信时遇到了一些问题。引发事件的顺序意味着用户控件上的操作在 post 后面发生得太晚，无法对主页产生影响。

例如，我在用户控件上有一个按钮，当按下该按钮时，会引发主页上正在侦听的自定义事件。当按下按钮时，post延期交货订单为：

page_load - on the main page

page_load - on the usercontrol (the user control is loaded programitically by the main page page_load)

The button call back on the user control

The event call back method on the main page

至此，事件回调方法对渲染页面产生任何影响似乎为时已晚，例如我正在尝试使用它更改正在显示的用户控件。

还有哪些其他技术可以用于这种通信？

相关代码主页：

    public string LastLoadedControl
    {
        get
        {
            return Session["LastLoaded"] as string;
        }
        set
        {
            Session["LastLoaded"] = value;
        }
    }

    private void LoadUserControl()
    {
        string controlPath = LastLoadedControl;

        ContentPlaceholder.Controls.Clear();

        if (string.IsNullOrEmpty(controlPath))
            controlPath = Utils.Paths.USERCTRL_BASE + "Main.ascx";

        Control uc = Page.LoadControl(controlPath);
        ContentPlaceholder.Controls.Add(uc);

    }

    protected void Page_Load(object sender, EventArgs e)
    {
        LoadUserControl();
        if (!IsPostBack)
            Utils.Events.redirectPage += Events_redirectPage;

    }

    private void Events_redirectPage(string path)
    {

        if (path.Equals("Main"))
        {
            //Session.Clear();
            //Session.Abandon();
        }
        else LastLoadedControl = Paths.USERCTRL_BASE + path + ".ascx"
        LoadUserControl();
    }

用户控制

    protected void profileBtn_Click(object sender, EventArgs e)
    {
        Utils.Events.triggerRedirectPage("Login");
    }

事件

public class Events
{
    public delegate void redirectEvent(string path);
    public static event redirectEvent redirectPage;

    public static void triggerRedirectPage(String path)
    {
        if (Utils.Events.redirectPage != null)
            Utils.Events.redirectPage(path);
    }
}

Answer 1

您可以采用两种方法。

方法一：

public interface IEventProvider
{
  void TriggerEvent();  
}

public class YourPage: Page, IEventProvider
{
   // Other page methods

   public void TriggerEvent()
   {
     // Your Implementation
   }
}

public class YourUserControl : WebUserControl
{
    protected void profileBtn_Click(object sender, EventArgs e)
    {
        IEventProvider eventProvider = this.Page as IEventProvider;
        if(eventProvider != null)
           eventProvider.TriggerEvent();
    }
}

方法二：

public interface IEventProvider
{
    // This does not have to be a boolean. You can use a string / enum / anything that suits your implementation
    bool Trigger {get; set;}
}

public class YourPage: Page, IEventProvider
{
   // Other page methods

   protected override void OnLoadComplete(EventArgs e)
   {
     // This will be raised when all the events have fired for all the controls in the page. 
     if(this.Trigger)
        TriggerEvent();
   }

   protected void TriggerEvent()
   {
     // Your code here
   }

   public bool Trigger
   {
     get;
     set;
   }
}

public class YourUserControl : WebUserControl
{
    protected void profileBtn_Click(object sender, EventArgs e)
    {
        IEventProvider eventProvider = this.Page as IEventProvider;
        if(eventProvider != null)
           eventProvider.Trigger = true;
    }
}

ASP 中用于从用户控件到父页面的通信的技术是什么？

What are techniques in ASP for communication from usercontrol to parent page?

c#

asp.net

events

user-controls

asp.net-ajax