WebPartManager.GetConsumerConnectionPoints(WebPart) Method

Reference

Definition

Namespace:: System.Web.UI.WebControls.WebParts

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

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

public:
 virtual System::Web::UI::WebControls::WebParts::ConsumerConnectionPointCollection ^ GetConsumerConnectionPoints(System::Web::UI::WebControls::WebParts::WebPart ^ webPart);

public virtual System.Web.UI.WebControls.WebParts.ConsumerConnectionPointCollection GetConsumerConnectionPoints (System.Web.UI.WebControls.WebParts.WebPart webPart);

abstract member GetConsumerConnectionPoints : System.Web.UI.WebControls.WebParts.WebPart -> System.Web.UI.WebControls.WebParts.ConsumerConnectionPointCollection
override this.GetConsumerConnectionPoints : System.Web.UI.WebControls.WebParts.WebPart -> System.Web.UI.WebControls.WebParts.ConsumerConnectionPointCollection

Public Overridable Function GetConsumerConnectionPoints (webPart As WebPart) As ConsumerConnectionPointCollection

Parameters

webPart: WebPart

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

Returns

ConsumerConnectionPointCollection

A ConsumerConnectionPointCollection that contains all connection points in the consumer.

Exceptions

ArgumentNullException

webPart is null.

Examples

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

The code 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 the topic 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 ConsumerConnectionPointCollection object that is retrieved by using the GetConsumerConnectionPoints 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>

<%@ Page Language="vb" %>
<%@ register TagPrefix="uc1" 
  TagName="DisplayModeMenuVB" 
  Src="DisplayModeMenuVB.ascx" %>
<%@ register tagprefix="aspSample" 
  Namespace="Samples.AspNet.VB.Controls" 
  Assembly="ConnectionSampleVB"%>

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

  Protected Sub Page_Load(ByVal sender As Object, _
    ByVal e As System.EventArgs)
    
    ' Define provider, consumer, and connection points.
    Dim provider As WebPart = mgr.WebParts("zip1")
    Dim provConnPoint As ProviderConnectionPoint = _
      mgr.GetProviderConnectionPoints(provider)("ZipCodeProvider")
    Dim consumer As WebPart = mgr.WebParts("weather1")
    Dim consConnPoint As ConsumerConnectionPoint = _
      mgr.GetConsumerConnectionPoints(consumer)("ZipCodeConsumer")
    
    ' Check whether the connection already exists.
    If mgr.CanConnectWebParts(provider, provConnPoint, _
      consumer, consConnPoint) Then
      ' Create a new static connection.
      Dim conn As New WebPartConnection()
      conn.ID = "staticConn1"
      conn.ConsumerID = "weather1"
      conn.ConsumerConnectionPointID = "ZipCodeConsumer"
      conn.ProviderID = "zip1"
      conn.ProviderConnectionPointID = "ZipCodeProvider"
      mgr.StaticConnections.Add(conn)
    End If
    
  End Sub
  
</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:DisplayModeMenuVB 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.

Remarks

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 consumer control, its connection points are ConsumerConnectionPoint objects. Retrieving the consumer connection points is a necessary step in forming a Web Parts connection.

A consumer must always have at least one connection point to be able to establish a connection. The GetConsumerConnectionPoints method checks a consumer control and retrieves a collection of all its connection points. If a WebPart control has no connection points, the method returns an empty collection.

Applies to

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