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WebPartManager.GetProviderConnectionPoints Method

Retrieves the collection of ProviderConnectionPoint objects that can act as connection points from a server control that is acting as a provider within a Web Parts connection.

Namespace:  System.Web.UI.WebControls.WebParts
Assembly:  System.Web (in System.Web.dll)

public virtual ProviderConnectionPointCollection GetProviderConnectionPoints(
	WebPart webPart
)

Parameters

webPart
Type: System.Web.UI.WebControls.WebParts.WebPart

A server control that is acting as a provider in a connection.

Return Value

Type: System.Web.UI.WebControls.WebParts.ProviderConnectionPointCollection
A ProviderConnectionPointCollection that contains all connection points in the provider.

ExceptionCondition
ArgumentNullException

webPart is null.

A Web Parts connection always involves exactly two controls, one acting as the provider of data, the other acting as the consumer of data. Each control must have one or more methods that are defined as connection points. In the case of a provider control, its connection points are ProviderConnectionPoint objects.

A provider must always have at least one connection point to be able to establish a connection. The GetProviderConnectionPoints method checks a provider control and retrieves a collection of all its connection points. Retrieving the provider connection points is a necessary step in forming a Web Parts connection.

The following code example demonstrates how to use the GetProviderConnectionPoints method.

The example has four parts:

  • A user control that enables you to change display modes on a Web Parts page.

  • A Web page that contains two custom WebPart controls that can be connected, and an <asp:webpartmanager> element.

  • A source code file that contains two custom WebPart controls and a custom interface.

  • An explanation of how the example works in a browser.

The first part of the code example is the user control for changing display modes. You can obtain the source code for the user control from the Example section of the WebPartManager class overview. For more information about display modes and how the user control works, see Walkthrough: Changing Display Modes on a Web Parts Page.

The declarative markup for the Web page contains Register directives for both the user control and the custom controls. There is an <asp:webpartmanager> element, an <asp:webpartzone> element to contain the custom controls, and an <asp:connectionszone> element. Notice that in the Page_Load method, the code checks to see whether a connection already exists and, if not, defines a provider, a consumer, and their respective connection points, and then adds a new connection to the set of static connections referenced by the StaticConnections property. Note that the ProviderConnectionPointCollection object that is retrieved by using the GetProviderConnectionPoints method is then passed to the CanConnectWebParts method to determine whether a connection between the two controls can be created.

<%@ Page Language="C#" %>
<%@ register TagPrefix="uc1" 
  TagName="DisplayModeMenuCS" 
  Src="DisplayModeMenuCS.ascx" %>
<%@ register tagprefix="aspSample" 
  Namespace="Samples.AspNet.CS.Controls" 
  Assembly="ConnectionSampleCS"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  protected void Page_Load(object sender, EventArgs e)
  {

    // Define provider, consumer, and connection points.
    WebPart provider = mgr.WebParts["zip1"];
    ProviderConnectionPoint provConnPoint =
      mgr.GetProviderConnectionPoints(provider)["ZipCodeProvider"];
    WebPart consumer = mgr.WebParts["weather1"];
    ConsumerConnectionPoint consConnPoint =
      mgr.GetConsumerConnectionPoints(consumer)["ZipCodeConsumer"];

    // Check whether the connection already exists.
    if (mgr.CanConnectWebParts(provider, provConnPoint,
      consumer, consConnPoint))
    {
      // Create a new static connection.
      WebPartConnection conn = new WebPartConnection();
      conn.ID = "staticConn1";
      conn.ConsumerID = "weather1";
      conn.ConsumerConnectionPointID = "ZipCodeConsumer";
      conn.ProviderID = "zip1";
      conn.ProviderConnectionPointID = "ZipCodeProvider";
      mgr.StaticConnections.Add(conn);
    }
 }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">
      <!-- Reference the WebPartManager control. -->
      <asp:WebPartManager ID="mgr" runat="server" />   
    <div>
      <uc1:DisplayModeMenuCS ID="displaymode1" 
        runat="server" />
      <!-- Reference consumer and provider controls 
           in a zone. -->
      <asp:WebPartZone ID="WebPartZone1" runat="server">
        <ZoneTemplate>
          <aspSample:ZipCodeWebPart ID="zip1" 
            runat="server" 
            Title="Zip Code Control"/>
          <aspSample:WeatherWebPart ID="weather1" 
            runat="server" 
            Title="Weather Control" />
        </ZoneTemplate>
      </asp:WebPartZone>
      <hr />
      <!-- Add a ConnectionsZone so users can connect 
           controls. -->
      <asp:ConnectionsZone ID="ConnectionsZone1" 
        runat="server" />
    </div>
    </form>
</body>
</html>

The third part of the example is the source code for the controls. You can obtain this code, and instructions for compiling it, from the Example section of the WebPartManager class overview.

After you have loaded the Web page in a browser, click the Display Mode drop-down list control and select Connect to switch the page to connect mode. Connect mode uses the <asp:connectionszone> element to enable you to create connections between controls. In connect mode, click the downward arrow in the title bar of the ZIP Code control to activate its verbs menu, and then click Connect. After the connection user interface (UI) appears, notice that a connection has already been created by the code contained in the Page_Load method. If you return to this page in a later browser session, this static connection will already be established and will not need to be recreated each time the page loads.

.NET Framework

Supported in: 4.6, 4, 3.5, 3.0, 2.0

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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