ConnectionPoint.AllowsMultipleConnections Property
Definition
Important
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Gets a value that indicates whether a connection point supports multiple simultaneous connections.
public:
property bool AllowsMultipleConnections { bool get(); };public bool AllowsMultipleConnections { get; }member this.AllowsMultipleConnections : boolPublic ReadOnly Property AllowsMultipleConnections As BooleanProperty Value
true if the connection point supports multiple connections; otherwise, false.
Examples
The following code example demonstrates the use of the AllowsMultipleConnections property on both ProviderConnectionPoint and ConsumerConnectionPoint objects. This code example shows only the Web page that contains the code to access the property; for the full code required to run the example, see the Example section of the ConnectionPoint class overview.
The code in the Button2_Click method of the Web page accesses the AllowsMultipleConnections property on each of the connection point objects and writes each value to a label. Execute the code by clicking the Connection Point Details button after the page is loaded in a browser.
<%@ Page Language="C#" %>
<%@ register tagprefix="uc1"
tagname="DisplayModeMenuCS"
src="~/displaymodemenucs.ascx" %>
<%@ Register TagPrefix="aspSample"
Namespace="Samples.AspNet.CS.Controls" %>
<!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 Button1_Click(object sender, EventArgs e)
{
ProviderConnectionPoint provPoint =
mgr.GetProviderConnectionPoints(zip1)["ZipCodeProvider"];
ConsumerConnectionPoint connPoint =
mgr.GetConsumerConnectionPoints(weather1)["ZipCodeConsumer"];
if(mgr.CanConnectWebParts(zip1, provPoint, weather1, connPoint))
mgr.ConnectWebParts(zip1, provPoint, weather1, connPoint);
}
protected void Button2_Click(object sender, EventArgs e)
{
WebPartConnection conn = mgr.Connections[0];
lblConn.Text = "<h2>Connection Point Details</h2>" +
"<h3>Provider Connection Point</h3>" +
" Display name: " + conn.ProviderConnectionPoint.DisplayName +
"<br />" +
" ID: " + conn.ProviderConnectionPoint.ID +
"<br />" +
" Interface type: " +
conn.ProviderConnectionPoint.InterfaceType.ToString() +
"<br />" +
" Control type: " + conn.ProviderConnectionPoint.ControlType.ToString() +
"<br />" +
" Allows multiple connections: " +
conn.ProviderConnectionPoint.AllowsMultipleConnections.ToString() +
"<br />" +
" Enabled: " + conn.ProviderConnectionPoint.GetEnabled(zip1).ToString() +
"<hr />" +
"<h3>Consumer Connection Point</h3>" +
" Display name: " + conn.ConsumerConnectionPoint.DisplayName +
"<br />" +
" ID: " + conn.ConsumerConnectionPoint.ID +
"<br />" +
" Interface type: " + conn.ConsumerConnectionPoint.InterfaceType.ToString() +
"<br />" +
" Control type: " + conn.ConsumerConnectionPoint.ControlType.ToString() +
"<br />" +
" Allows multiple connections: " +
conn.ConsumerConnectionPoint.AllowsMultipleConnections.ToString() +
"<br />" +
" Enabled: " + conn.ConsumerConnectionPoint.GetEnabled(zip1).ToString();
}
protected void Page_Load(object sender, EventArgs e)
{
lblConn.Text = String.Empty;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:WebPartManager ID="mgr" runat="server" >
<StaticConnections>
<asp:WebPartConnection ID="conn1"
ConsumerConnectionPointID="ZipCodeConsumer"
ConsumerID="weather1"
ProviderConnectionPointID="ZipCodeProvider"
ProviderID="zip1" />
</StaticConnections>
</asp:WebPartManager>
<uc1:displaymodemenucs id="menu1" runat="server" />
<asp:WebPartZone ID="WebPartZone1" runat="server">
<ZoneTemplate>
<aspSample:ZipCodeWebPart ID="zip1" runat="server"
Title="Zip Code Provider" />
<aspSample:WeatherWebPart ID="weather1" runat="server"
Title="Zip Code Consumer" />
</ZoneTemplate>
</asp:WebPartZone>
<asp:ConnectionsZone ID="ConnectionsZone1" runat="server">
</asp:ConnectionsZone>
<asp:Button ID="Button1" runat="server"
Text="Dynamic Connection"
OnClick="Button1_Click" />
<br />
<asp:Button ID="Button2" runat="server"
Text="Connection Point Details"
OnClick="Button2_Click" />
<br />
<asp:Label ID="lblConn" 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" %>
<!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 Button1_Click(ByVal sender As Object, _
ByVal e As System.EventArgs)
Dim provPoint As ProviderConnectionPoint = _
mgr.GetProviderConnectionPoints(zip1)("ZipCodeProvider")
Dim connPoint As ConsumerConnectionPoint = _
mgr.GetConsumerConnectionPoints(weather1)("ZipCodeConsumer")
If mgr.CanConnectWebParts(zip1, provPoint, weather1, connPoint) Then
mgr.ConnectWebParts(zip1, provPoint, weather1, connPoint)
End If
End Sub
Protected Sub Button2_Click(ByVal sender As Object, _
ByVal e As System.EventArgs)
Dim conn As WebPartConnection = mgr.Connections(0)
lblConn.Text = "<h2>Connection Point Details</h2>" & _
"<h3>Provider Connection Point</h3>" & _
" Display name: " & conn.ProviderConnectionPoint.DisplayName & _
"<br />" & _
" ID: " & conn.ProviderConnectionPoint.ID & _
"<br />" & _
" Interface type: " & conn.ProviderConnectionPoint.InterfaceType.ToString() & _
"<br />" & _
" Control type: " & conn.ProviderConnectionPoint.ControlType.ToString() & _
"<br />" & _
" Allows multiple connections: " & _
conn.ProviderConnectionPoint.AllowsMultipleConnections.ToString() & _
"<br />" & _
" Enabled: " & conn.ProviderConnectionPoint.GetEnabled(zip1).ToString() & _
"<hr />" & _
"<h3>Consumer Connection Point</h3>" & _
" Display name: " & conn.ConsumerConnectionPoint.DisplayName & _
"<br />" & _
" ID: " & conn.ConsumerConnectionPoint.ID & _
"<br />" & _
" Interface type: " & conn.ConsumerConnectionPoint.InterfaceType.ToString() & _
"<br />" & _
" Control type: " & conn.ConsumerConnectionPoint.ControlType.ToString() & _
"<br />" & _
" Allows multiple connections: " & _
conn.ConsumerConnectionPoint.AllowsMultipleConnections.ToString() & _
"<br />" & _
" Enabled: " & conn.ConsumerConnectionPoint.GetEnabled(zip1).ToString()
End Sub
Protected Sub Page_Load(ByVal sender As Object, _
ByVal e As System.EventArgs)
lblConn.Text = String.Empty
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:WebPartManager ID="mgr" runat="server" >
<StaticConnections>
<asp:WebPartConnection ID="conn1"
ConsumerConnectionPointID="ZipCodeConsumer"
ConsumerID="weather1"
ProviderConnectionPointID="ZipCodeProvider"
ProviderID="zip1" />
</StaticConnections>
</asp:WebPartManager>
<uc1:displaymodemenuvb id="menu1" runat="server" />
<asp:WebPartZone ID="WebPartZone1" runat="server">
<ZoneTemplate>
<aspSample:ZipCodeWebPart ID="zip1" runat="server"
Title="Zip Code Provider" />
<aspSample:WeatherWebPart ID="weather1" runat="server"
Title="Zip Code Consumer" />
</ZoneTemplate>
</asp:WebPartZone>
<asp:ConnectionsZone ID="ConnectionsZone1" runat="server">
</asp:ConnectionsZone>
<asp:Button ID="Button1" runat="server"
Text="Dynamic Connection"
OnClick="Button1_Click" />
<br />
<asp:Button ID="Button2" runat="server"
Text="Connection Point Details"
OnClick="Button2_Click" />
<br />
<asp:Label ID="lblConn" runat="server" />
</div>
</form>
</body>
</html>
Remarks
ProviderConnectionPoint objects have their AllowsMultipleConnections property value set to true (by the ConnectionProviderAttribute class), because the Web Parts control set by default enables provider connection points to form connections to multiple consumers.
In contrast, ConsumerConnectionPoint objects have their AllowsMultipleConnections property value set to false (by the ConnectionConsumerAttribute class) because the Web Parts control set by default allows consumer connection points to establish a connection to only one provider at a time.
You can change the default behavior concerning multiple connections by assigning different values to the ConnectionProviderAttribute.AllowsMultipleConnections property (for providers) or the ConnectionConsumerAttribute.AllowsMultipleConnections property (for consumers) on the two Attribute classes used for connection attributes. If you enable consumer connection points to connect to multiple providers at the same time, your code must deal with any resulting synchronization issues.
