WebPartManager.CanConnectWebParts 方法

參考

定義

命名空間:: System.Web.UI.WebControls.WebParts

組件:: System.Web.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

檢查將參與連接的 WebPart 控制項，以判斷這些控制項是否可以連接。

多載

CanConnectWebParts(WebPart, ProviderConnectionPoint, WebPart, ConsumerConnectionPoint)	當提供者和消費者控制項有相容的介面，並且不需要 WebPart 物件時，檢查將參與連接的 WebPartTransformer 控制項是否可以連接。
CanConnectWebParts(WebPart, ProviderConnectionPoint, WebPart, ConsumerConnectionPoint, WebPartTransformer)	檢查將參與連接的 WebPart 控制項，以判斷它們是否可以連接，並且使用 WebPartTransformer 物件，來建立不相容消費者和提供者之間的連接。

備註

方法 CanConnectWebParts 可用來判斷是否可以連接兩個 WebPart 控件。方法通常會在呼叫 ConnectWebParts 方法之前用來做為條件式檢查。

方法會 CanConnectWebParts 檢查一些必須符合的準則，才能讓兩個控件形成連接。下列清單摘要說明建立連線的主要準則。如果符合上述所有準則 (加上一些額外的內部條件) ，此方法會傳 true回，這表示控制件可以連線：

提供者和取用者控制項不能是 null，而且它們必須包含在屬性所參考的控件集合中 WebParts 。
提供者和取用者不能是相同的控制件。換句話說， WebPart 控件無法連接到本身。
提供者 ConnectionPoint 與取用者) (連線點的物件不能是 null。
提供者和取用者無法關閉 (無法) 控件的 IsClosed 屬性 true 。
連接 ControlType 點控制件的屬性必須符合取用者和提供者的控制項類型。
必須同時啟用連接點， (其 GetEnabled 方法必須同時傳回 true) 。
每個連接點都不能嘗試形成比本身 AllowsMultipleConnections 屬性中指定的更多連接。
WebPartTransformer如果需要物件 (轉換程式) 才能連線不相容的控制件，則不能是 null。不過，如果控制件已經相容，轉換程式必須是 null。
如果使用) ，則必須在集合中 AvailableTransformers 參考轉換器 (。
如果) 使用的轉換 (程式必須具有與提供者和取用者相容的介面，才能轉換兩個控件之間的數據。取用者和提供者的次要介面也必須相容。

CanConnectWebParts(WebPart, ProviderConnectionPoint, WebPart, ConsumerConnectionPoint)

當提供者和消費者控制項有相容的介面，並且不需要 WebPart 物件時，檢查將參與連接的 WebPartTransformer 控制項是否可以連接。

public:
 bool CanConnectWebParts(System::Web::UI::WebControls::WebParts::WebPart ^ provider, System::Web::UI::WebControls::WebParts::ProviderConnectionPoint ^ providerConnectionPoint, System::Web::UI::WebControls::WebParts::WebPart ^ consumer, System::Web::UI::WebControls::WebParts::ConsumerConnectionPoint ^ consumerConnectionPoint);

public bool CanConnectWebParts (System.Web.UI.WebControls.WebParts.WebPart provider, System.Web.UI.WebControls.WebParts.ProviderConnectionPoint providerConnectionPoint, System.Web.UI.WebControls.WebParts.WebPart consumer, System.Web.UI.WebControls.WebParts.ConsumerConnectionPoint consumerConnectionPoint);

member this.CanConnectWebParts : System.Web.UI.WebControls.WebParts.WebPart * System.Web.UI.WebControls.WebParts.ProviderConnectionPoint * System.Web.UI.WebControls.WebParts.WebPart * System.Web.UI.WebControls.WebParts.ConsumerConnectionPoint -> bool

Public Function CanConnectWebParts (provider As WebPart, providerConnectionPoint As ProviderConnectionPoint, consumer As WebPart, consumerConnectionPoint As ConsumerConnectionPoint) As Boolean

參數

provider: WebPart

當兩個控制項連接時，提供資料給 consumer 的控制項。

providerConnectionPoint: ProviderConnectionPoint

讓 provider 參與連接的 ConnectionPoint。

consumer: WebPart

當兩個控制項連接時，從 provider 接收資料的控制項。

consumerConnectionPoint: ConsumerConnectionPoint

做為回呼方法的 ConnectionPoint，讓 consumer 可以參與連接。

傳回

Boolean

布林值，指出 provider 和 consumer 是否可以連接。

範例

下列程式代碼範例示範如何使用這個方法。

程式代碼範例有四個部分：

使用者控制元件，可讓您變更網頁元件頁面上的顯示模式。
網頁，其中包含兩個可連接的自定義 WebPart 控件、專案 <asp:webpartmanager> ，以及一些使用 CanConnectWebParts 方法建立連接的事件處理程序代碼。
包含兩個自定義 WebPart 控件和自定義介面的原始碼檔案。
說明範例在瀏覽器中的運作方式。

程式代碼範例的第一個部分是變更顯示模式的使用者控件。您可以從類別概觀的 Example 區段取得使用者控制件的 WebPartManager 原始碼。如需顯示模式和使用者控件運作方式的詳細資訊，請參閱逐步解說：變更網頁元件頁面上的顯示模式。

網頁的宣告式標記包含 Register 使用者控件和自定義控件的指示詞。有專案 <asp:webpartmanager> 、 <asp:webpartzone> 要包含自定義控件的元素，以及專案 <asp:connectionszone> 。請注意，在方法中 Page_Load ，程式代碼會檢查是否可以建立連接，如果是的話，會定義提供者、取用者及其各自的連接點，然後將新的連接加入屬性所 StaticConnections 參考的靜態連接集。

<%@ 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>

範例的第三個部分是控件的原始程式碼。它包含介面和兩個自定義 WebPart 控件，一個做為提供者，另一個做為取用者。因為它們有相容的連接點， (兩者都辨識 IZipCode 介面) ，所以不需要轉換程式來進行連接。若要執行程式碼範例，您必須編譯此原始程式碼。您可以明確地編譯它，並將產生的元件放在網站的 Bin 資料夾或全域程式集緩存中。或者，您可以將原始程式碼放在月臺的 App_Code資料夾中，其將在運行時間動態編譯。如需示範如何編譯的逐步解說，請參閱逐步解說：開發和使用自定義 Web 伺服器控制件。

namespace Samples.AspNet.CS.Controls
{
  using System;
  using System.Web;
  using System.Web.Security;
  using System.Security.Permissions;
  using System.Web.UI;
  using System.Web.UI.WebControls;
  using System.Web.UI.WebControls.WebParts;

  [AspNetHostingPermission(SecurityAction.Demand,
    Level = AspNetHostingPermissionLevel.Minimal)]
  [AspNetHostingPermission(SecurityAction.InheritanceDemand,
    Level = AspNetHostingPermissionLevel.Minimal)]
  public interface IZipCode
  {
    string ZipCode { get; set;}
  }

  [AspNetHostingPermission(SecurityAction.Demand,
    Level = AspNetHostingPermissionLevel.Minimal)]
  [AspNetHostingPermission(SecurityAction.InheritanceDemand,
    Level = AspNetHostingPermissionLevel.Minimal)]
  public class ZipCodeWebPart : WebPart, IZipCode
  {
    string zipCodeText = String.Empty;
    TextBox input;
    Button send;

    public ZipCodeWebPart()
    {
    }

    // Make the implemented property personalizable to save 
    // the Zip Code between browser sessions.
    [Personalizable()]
    public virtual string ZipCode
    {
      get { return zipCodeText; }
      set { zipCodeText = value; }
    }

    // This is the callback method that returns the provider.
    [ConnectionProvider("Zip Code", "ZipCodeProvider")]
    public IZipCode ProvideIZipCode()
    {
      return this;
    }

    protected override void CreateChildControls()
    {
      Controls.Clear();
      input = new TextBox();
      this.Controls.Add(input);
      send = new Button();
      send.Text = "Enter 5-digit Zip Code";
      send.Click += new EventHandler(this.submit_Click);
      this.Controls.Add(send);
    }

    private void submit_Click(object sender, EventArgs e)
    {
      if (!string.IsNullOrEmpty(input.Text))
      {
        zipCodeText = Page.Server.HtmlEncode(input.Text);
        input.Text = String.Empty;
      }
    }
  }

  [AspNetHostingPermission(SecurityAction.Demand,
    Level = AspNetHostingPermissionLevel.Minimal)]
  [AspNetHostingPermission(SecurityAction.InheritanceDemand,
    Level = AspNetHostingPermissionLevel.Minimal)]
  public class WeatherWebPart : WebPart
  {
    private IZipCode _provider;
    string _zipSearch;
    Label DisplayContent;

    // This method is identified by the ConnectionConsumer 
    // attribute, and is the mechanism for connecting with 
    // the provider. 
    [ConnectionConsumer("Zip Code", "ZipCodeConsumer")]
    public void GetIZipCode(IZipCode Provider)
    {
      _provider = Provider;
    }
    
    protected override void OnPreRender(EventArgs e)
    {
      EnsureChildControls();

      if (this._provider != null)
      {
        _zipSearch = _provider.ZipCode.Trim();
        DisplayContent.Text = "My Zip Code is:  " + _zipSearch;
      }
    }

    protected override void CreateChildControls()
    {
      Controls.Clear();
      DisplayContent = new Label();
      this.Controls.Add(DisplayContent);
    }
  }
}

Imports System.Web
Imports System.Web.Security
Imports System.Security.Permissions
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts

Namespace Samples.AspNet.VB.Controls

  <AspNetHostingPermission(SecurityAction.Demand, _
    Level:=AspNetHostingPermissionLevel.Minimal)> _
  <AspNetHostingPermission(SecurityAction.InheritanceDemand, _
    Level:=AspNetHostingPermissionLevel.Minimal)> _
  Public Interface IZipCode

    Property ZipCode() As String

  End Interface

  <AspNetHostingPermission(SecurityAction.Demand, _
    Level:=AspNetHostingPermissionLevel.Minimal)> _
  <AspNetHostingPermission(SecurityAction.InheritanceDemand, _
    Level:=AspNetHostingPermissionLevel.Minimal)> _
  Public Class ZipCodeWebPart
    Inherits WebPart
    Implements IZipCode
    Private zipCodeText As String = String.Empty
    Private input As TextBox
    Private send As Button

    Public Sub New()
    End Sub

    ' Make the implemented property personalizable to save 
    ' the Zip Code between browser sessions.
    <Personalizable()> _
    Public Property ZipCode() As String _
      Implements IZipCode.ZipCode

      Get
        Return zipCodeText
      End Get
      Set(ByVal value As String)
        zipCodeText = value
      End Set
    End Property

    ' This is the callback method that returns the provider.
    <ConnectionProvider("Zip Code", "ZipCodeProvider")> _
    Public Function ProvideIZipCode() As IZipCode
      Return Me
    End Function


    Protected Overrides Sub CreateChildControls()
      Controls.Clear()
      input = New TextBox()
      Me.Controls.Add(input)
      send = New Button()
      send.Text = "Enter 5-digit Zip Code"
      AddHandler send.Click, AddressOf Me.submit_Click
      Me.Controls.Add(send)

    End Sub


    Private Sub submit_Click(ByVal sender As Object, _
      ByVal e As EventArgs)

      If input.Text <> String.Empty Then
        zipCodeText = Page.Server.HtmlEncode(input.Text)
        input.Text = String.Empty
      End If

    End Sub

  End Class

  <AspNetHostingPermission(SecurityAction.Demand, _
    Level:=AspNetHostingPermissionLevel.Minimal)> _
  <AspNetHostingPermission(SecurityAction.InheritanceDemand, _
    Level:=AspNetHostingPermissionLevel.Minimal)> _
  Public Class WeatherWebPart
    Inherits WebPart
    Private _provider As IZipCode
    Private _zipSearch As String
    Private DisplayContent As Label

    ' This method is identified by the ConnectionConsumer 
    ' attribute, and is the mechanism for connecting with 
    ' the provider. 
    <ConnectionConsumer("Zip Code", "ZipCodeConsumer")> _
    Public Sub GetIZipCode(ByVal Provider As IZipCode)
      _provider = Provider
    End Sub


    Protected Overrides Sub OnPreRender(ByVal e As EventArgs)
      EnsureChildControls()

      If Not (Me._provider Is Nothing) Then
        _zipSearch = _provider.ZipCode.Trim()
                DisplayContent.Text = "My Zip Code is:  " + _zipSearch
      End If

    End Sub

    Protected Overrides Sub CreateChildControls()
      Controls.Clear()
      DisplayContent = New Label()
      Me.Controls.Add(DisplayContent)

    End Sub

  End Class

End Namespace

在瀏覽器中載入網頁之後，按兩下 [ 顯示模式 ] 下拉式清單控制件，然後選取[ 連線 ] 以切換頁面以連線模式。連接模式會 <asp:connectionszone> 使用元素，讓您建立控件之間的連線。在連線模式中，按兩下 郵政編碼 控件標題列中的向下箭號，以啟動其動詞功能表，然後按兩下 [ 連接]。 (UI) 連線使用者介面出現之後，請注意，方法中包含的 Page_Load 程式代碼已經建立連線。

備註

當這兩個控件都有相容的連接點類型時，會使用這個方法進行連接providerconsumer，因此WebPartTransformer不需要物件。您可能想要使用這個方法來確認兩個控件可以在呼叫 ConnectWebParts 以建立程式設計連接之前連線。

此多載使用與方法多載相同的實 CanConnectWebParts(WebPart, ProviderConnectionPoint, WebPart, ConsumerConnectionPoint, WebPartTransformer) 作，唯一的例外狀況是此多載不需要轉換器。

另請參閱

ASP.NET 網頁元件控制件

適用於

CanConnectWebParts(WebPart, ProviderConnectionPoint, WebPart, ConsumerConnectionPoint, WebPartTransformer)

檢查將參與連接的 WebPart 控制項，以判斷它們是否可以連接，並且使用 WebPartTransformer 物件，來建立不相容消費者和提供者之間的連接。

public:
 virtual bool CanConnectWebParts(System::Web::UI::WebControls::WebParts::WebPart ^ provider, System::Web::UI::WebControls::WebParts::ProviderConnectionPoint ^ providerConnectionPoint, System::Web::UI::WebControls::WebParts::WebPart ^ consumer, System::Web::UI::WebControls::WebParts::ConsumerConnectionPoint ^ consumerConnectionPoint, System::Web::UI::WebControls::WebParts::WebPartTransformer ^ transformer);

public virtual bool CanConnectWebParts (System.Web.UI.WebControls.WebParts.WebPart provider, System.Web.UI.WebControls.WebParts.ProviderConnectionPoint providerConnectionPoint, System.Web.UI.WebControls.WebParts.WebPart consumer, System.Web.UI.WebControls.WebParts.ConsumerConnectionPoint consumerConnectionPoint, System.Web.UI.WebControls.WebParts.WebPartTransformer transformer);

abstract member CanConnectWebParts : System.Web.UI.WebControls.WebParts.WebPart * System.Web.UI.WebControls.WebParts.ProviderConnectionPoint * System.Web.UI.WebControls.WebParts.WebPart * System.Web.UI.WebControls.WebParts.ConsumerConnectionPoint * System.Web.UI.WebControls.WebParts.WebPartTransformer -> bool
override this.CanConnectWebParts : System.Web.UI.WebControls.WebParts.WebPart * System.Web.UI.WebControls.WebParts.ProviderConnectionPoint * System.Web.UI.WebControls.WebParts.WebPart * System.Web.UI.WebControls.WebParts.ConsumerConnectionPoint * System.Web.UI.WebControls.WebParts.WebPartTransformer -> bool

Public Overridable Function CanConnectWebParts (provider As WebPart, providerConnectionPoint As ProviderConnectionPoint, consumer As WebPart, consumerConnectionPoint As ConsumerConnectionPoint, transformer As WebPartTransformer) As Boolean

參數

provider: WebPart

當兩個控制項連接時，提供資料給 consumer 的控制項。

providerConnectionPoint: ProviderConnectionPoint

做為回呼方法的 ConnectionPoint，讓 provider 可以參與連接。

consumer: WebPart

當兩個控制項連接時，從 provider 接收資料的控制項。

consumerConnectionPoint: ConsumerConnectionPoint

做為回呼方法的 ConnectionPoint，讓 consumer 可以參與連接。

transformer: WebPartTransformer

WebPartTransformer，允許不相容的 provider 和 consumer 連接。

傳回

Boolean

布林值，指出 provider 和 consumer 是否可以建立連接。

備註

當這兩個控件都有不相容的連接點類型時，會使用這個方法進行連接providerconsumer，因此WebPartTransformer需要物件。您可能想要使用這個方法來確認兩個控件可以在呼叫 ConnectWebParts 以建立程式設計連接之前連線。

此多載使用與方法多載相同的實 CanConnectWebParts(WebPart, ProviderConnectionPoint, WebPart, ConsumerConnectionPoint) 作，唯一的例外狀況是此多載需要轉換器。

適用於

共用方式為

WebPartManager.CanConnectWebParts 方法

定義

多載

備註

CanConnectWebParts(WebPart, ProviderConnectionPoint, WebPart, ConsumerConnectionPoint)

參數

傳回

範例

備註

另請參閱

適用於

CanConnectWebParts(WebPart, ProviderConnectionPoint, WebPart, ConsumerConnectionPoint, WebPartTransformer)

參數

傳回

備註

適用於

其他資源