FormView.ItemCommand イベント

定義

FormView コントロール内のボタンをクリックすると発生します。Occurs when a button within a FormView control is clicked.

public:
 event System::Web::UI::WebControls::FormViewCommandEventHandler ^ ItemCommand;
public event System.Web.UI.WebControls.FormViewCommandEventHandler ItemCommand;
member this.ItemCommand : System.Web.UI.WebControls.FormViewCommandEventHandler 
Public Custom Event ItemCommand As FormViewCommandEventHandler 

イベントの種類

FormViewCommandEventHandler

次の例は、イベントを使用して、 ItemCommand コントロールのボタンクリックを処理する方法を示して FormView います。The following example demonstrates how to use the ItemCommand event to handle a button click in a FormView control. ユーザーが [追加] ボタンをクリックすると、現在表示されている項目がコントロールに追加され ListBox ます。When the user clicks the Add button, the currently displayed item is added to a ListBox control.


<%@ Page language="C#" %>

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

  void ProductFormView_ItemCommand(Object sender, FormViewCommandEventArgs e)
  {

    // The ItemCommand event is raised when any button within
    // the FormView control is clicked. Use the CommandName property 
    // to determine which button was clicked. 
    if (e.CommandName == "Add")
    {

      // Add the product to the ListBox control. 
      
      // Use the Row property to retrieve the data row.
      FormViewRow row = ProductFormView.Row;
      
      // Retrieve the ProductNameLabel control from
      // the data row.
      Label productNameLabel = (Label)row.FindControl("ProductNameLabel");

      // Retrieve the QuantityTextBox control from
      // the data row.
      TextBox quantityTextBox = (TextBox)row.FindControl("QuantityTextBox");

      if (productNameLabel != null && quantityTextBox != null)
      {    
        // Get the product name from the ProductNameLabel control.
        string name = productNameLabel.Text;
        
        // Get the quantity from the QuantityTextBox control.
        string quantity = quantityTextBox.Text;

        // Create the text to display in the ListBox control.
        string description = name + " - " + quantity + " Qty";

        // Create a ListItem object using the description and
        // product name.
        ListItem item = new ListItem(description, name);

        // Add the ListItem object to the ListBox.
        ProductListBox.Items.Add(item);

        // Use the CommandSource property to retrieve
        // the Add button. Disable the button after
        // the user adds the currently displayed employee
        // name to the ListBox control.
        Button addButton = (Button)e.CommandSource;
        addButton.Enabled = false;
      }

    }

  }

  void ProductFormView_DataBound(Object sender, EventArgs e)
  {
    
    // To prevent the user from adding duplicate items, 
    // disable the Add button if the item being bound to the 
    // FormView control is already in the ListBox control.
    
    // Use the Row property to retrieve the data row.
    FormViewRow row = ProductFormView.Row;

    // Retrieve the Add button from the data row.
    Button addButton = (Button)row.FindControl("AddButton");

    // Retrieve the ProductNameLabel control from
    // data row.
    Label productNameLabel = (Label)row.FindControl("ProductNameLabel");

    if (addButton != null && productNameLabel != null)
    {
      // Get the product name from the ProductNameLabel 
      // control.
      string name = productNameLabel.Text;

      // Use the FindByValue method to determine whether
      // the ListBox control already contains an entry for
      // the item.
      ListItem item = ProductListBox.Items.FindByValue(name);

      // Disable the Add button if the ListBox control
      // already contains the item.
      if (item != null)
      {
        addButton.Enabled = false;
      }
      else
      {
        addButton.Enabled = true;
      }
    }

  }
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewCommandEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewCommandEventArgs Example</h3>
                       
      <asp:formview id="ProductFormView"
        datasourceid="ProductSource"
        allowpaging="true"
        datakeynames="ProductID"
        onitemcommand="ProductFormView_ItemCommand"
        ondatabound="ProductFormView_DataBound"  
        runat="server">
        
        <itemtemplate>
        
          <table>
            <tr>
              <td style="width:400px">
                <b>Description:</b>
                <asp:label id="ProductNameLabel"
                  text='<%# Eval("ProductName") %>'
                  runat='server'/>
                <br/>      
                <b>Price:</b>
                <asp:label id="PriceLabel"
                  text='<%# Eval("UnitPrice", "{0:c}") %>'
                  runat='server'/>
                <br/>  
                <asp:textbox id="QuantityTextBox"
                  width="50px"
                  maxlength="3" 
                  runat="server"/> Qty                   
              </td>
            </tr>
            <tr>
              <td>
                <asp:requiredfieldvalidator ID="QuantityRequiredValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter a quantity."
                  display="Static"
                  runat="server"/>
                <br/>
                <asp:CompareValidator id="QuantityCompareValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter an integer value."
                  display="Static"
                  type="Integer"
                  operator="DataTypeCheck"  
                  runat="server"/>    
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="AddButton"
                  text="Add"
                  commandname="Add"
                  runat="server"/>
              </td>
            </tr>
          </table>
        
        </itemtemplate>
                  
      </asp:formview>
      
      <br/><br/><hr/>
      
      Items:<br/>
      <asp:listbox id="ProductListBox"
        runat="server"/>
          
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="ProductSource"
        selectcommand="Select [ProductID], [ProductName], [UnitPrice] From [Products]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>


<%@ Page language="VB" %>

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

  Sub ProductFormView_ItemCommand(ByVal sender As Object, ByVal e As FormViewCommandEventArgs)

    ' The ItemCommand event is raised when any button within
    ' the FormView control is clicked. Use the CommandName property 
    ' to determine which button was clicked. 
    If e.CommandName = "Add" Then

      ' Add the product to the ListBox control. 
      
      ' Use the Row property to retrieve the data row.
      Dim row As FormViewRow = ProductFormView.Row
      
      ' Retrieve the ProductNameLabel control from
      ' the data row.
      Dim productNameLabel As Label = CType(row.FindControl("ProductNameLabel"), Label)

      ' Retrieve the QuantityTextBox control from
      ' the data row.
      Dim quantityTextBox As TextBox = CType(row.FindControl("QuantityTextBox"), TextBox)

      If productNameLabel IsNot Nothing And quantityTextBox IsNot Nothing Then
          
        ' Get the product name from the ProductNameLabel control.
        Dim name As String = productNameLabel.Text
        
        ' Get the quantity from the QuantityTextBox control.
        Dim quantity As String = quantityTextBox.Text

        ' Create the text to display in the ListBox control.
        Dim description As String = name & " - " & quantity & " Qty"

        ' Create a ListItem object using the description and
        ' product name.
        Dim item As new ListItem(description, name)

        ' Add the ListItem object to the ListBox.
        ProductListBox.Items.Add(item)

        ' Use the CommandSource property to retrieve
        ' the Add button. Disable the button after
        ' the user adds the currently displayed employee
        ' name to the ListBox control.
        Dim addButton As Button = CType(e.CommandSource, Button)
        addButton.Enabled = False
        
      End If

    End If

  End Sub

  Sub ProductFormView_DataBound(ByVal sender As Object, ByVal e As EventArgs)
    
    ' To prevent the user from adding duplicate items, 
    ' disable the Add button if the item being bound to the 
    ' FormView control is already in the ListBox control.
    
    ' Use the Row property to retrieve the data row.
    Dim row As FormViewRow = ProductFormView.Row

    ' Retrieve the Add button from the data row.
    Dim addButton As Button = CType(row.FindControl("AddButton"), Button)

    ' Retrieve the ProductNameLabel control from
    ' data row.
    Dim productNameLabel As Label = CType(row.FindControl("ProductNameLabel"), Label)

    If addButton IsNot Nothing And productNameLabel IsNot Nothing Then
    
      ' Get the product name from the ProductNameLabel 
      ' control.
      Dim name As String = productNameLabel.Text

      ' Use the FindByValue method to determine whether
      ' the ListBox control already contains an entry for
      ' the item.
      Dim item As ListItem = ProductListBox.Items.FindByValue(name)

      ' Disable the Add button if the ListBox control
      ' already contains the item.
      If item IsNot Nothing Then
      
        addButton.Enabled = False
      
      Else
      
        addButton.Enabled = True
        
      End If
      
    End If

  End Sub
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewCommandEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewCommandEventArgs Example</h3>
                       
      <asp:formview id="ProductFormView"
        datasourceid="ProductSource"
        allowpaging="true"
        datakeynames="ProductID"
        onitemcommand="ProductFormView_ItemCommand"
        ondatabound="ProductFormView_DataBound"  
        runat="server">
        
        <itemtemplate>
        
          <table>
            <tr>
              <td style="width:400px">
                <b>Description:</b>
                <asp:label id="ProductNameLabel"
                  text='<%# Eval("ProductName") %>'
                  runat='server'/>
                <br/>      
                <b>Price:</b>
                <asp:label id="PriceLabel"
                  text='<%# Eval("UnitPrice", "{0:c}") %>'
                  runat='server'/>
                <br/>  
                <asp:textbox id="QuantityTextBox"
                  width="50px"
                  maxlength="3" 
                  runat="server"/> Qty                   
              </td>
            </tr>
            <tr>
              <td>
                <asp:requiredfieldvalidator ID="QuantityRequiredValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter a quantity."
                  display="Static"
                  runat="server"/>
                <br/>
                <asp:CompareValidator id="QuantityCompareValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter an integer value."
                  display="Static"
                  type="Integer"
                  operator="DataTypeCheck"  
                  runat="server"/>    
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="AddButton"
                  text="Add"
                  commandname="Add"
                  runat="server"/>
              </td>
            </tr>
          </table>
        
        </itemtemplate>
                  
      </asp:formview>
      
      <br/><br/><hr/>
      
      Items:<br/>
      <asp:listbox id="ProductListBox"
        runat="server"/>
          
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="ProductSource"
        selectcommand="Select [ProductID], [ProductName], [UnitPrice] From [Products]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>

注釈

イベントは、 ItemCommand コントロール内のボタンがクリックされると発生し FormView ます。The ItemCommand event is raised when a button within the FormView control is clicked. これにより、このイベントが発生するたびにカスタムルーチンを実行するイベント処理メソッドを提供できます。This allows you to provide an event-handling method that performs a custom routine whenever this event occurs.

コントロール内のボタンは FormView 、コントロールの組み込み機能の一部を呼び出すこともできます。Buttons within a FormView control can also invoke some of the built-in functionality of the control. これらの操作のいずれかを実行するには、 CommandName ボタンのプロパティを次の表のいずれかの値に設定します。To perform one of these operations, set the CommandName property of a button to one of the values in the following table.

CommandName 値CommandName value 説明Description
中断"Cancel" 編集操作または挿入操作をキャンセルし、 FormView プロパティによって指定されたモードにコントロールを返し DefaultMode ます。Cancels an edit or insert operation and returns the FormView control to the mode specified by the DefaultMode property. イベントとイベントを発生させ ModeChanged ModeChanging ます。Raises the ModeChanged and ModeChanging events.
"削除""Delete" 現在のレコードを削除します。Deletes the current record. イベントとイベントを発生させ ItemDeleted ItemDeleting ます。Raises the ItemDeleted and ItemDeleting events.
編集"Edit" コントロールを FormView 編集モードにします。Puts the FormView control in edit mode. イベントとイベントを発生させ ModeChanged ModeChanging ます。Raises the ModeChanged and ModeChanging events.
Insert"Insert" 現在のレコードをデータ ソースに挿入します。Inserts the current record in the data source. イベントとイベントを発生させ ItemInserted ItemInserting ます。Raises the ItemInserted and ItemInserting events.
New"New" コントロールを FormView 挿入モードにします。Puts the FormView control in insert mode. イベントとイベントを発生させ ModeChanged ModeChanging ます。Raises the ModeChanged and ModeChanging events.
"Page" ページング操作を実行します。Performs a paging operation. CommandArgumentボタンのプロパティを "First"、"Last"、"Next"、"Prev"、またはページ番号に設定して、実行するページング操作の種類を指定します。Set the CommandArgument property of the button to "First", "Last", "Next", "Prev", or a page number to specify the type of paging operation to perform. イベントとイベントを発生させ PageIndexChanged PageIndexChanging ます。Raises the PageIndexChanged and PageIndexChanging events.
Update"Update" データ ソースの現在のレコードを更新します。Updates the current record in the data source. イベントとイベントを発生させ ItemUpdated ItemUpdating ます。Raises the ItemUpdated and ItemUpdating events.

イベントは、 ItemCommand 前の表に一覧表示されているボタンをクリックしたときに発生しますが、この操作については、表に示されているイベントを使用することをお勧めします。Although the ItemCommand event is raised when a button listed in the previous table is clicked, it is recommended that you use the events listed in the table for the operation.

FormViewCommandEventArgsオブジェクトがイベント処理メソッドに渡されます。これにより、クリックされたボタンのコマンド名とコマンド引数を確認できます。A FormViewCommandEventArgs object is passed to the event-handling method, which allows you to determine the command name and command argument of the button clicked. コマンド名とコマンド引数を決定するには、 CommandName CommandArgument それぞれプロパティとプロパティを使用します。To determine the command name and command argument, use the CommandName and CommandArgument properties, respectively. また、プロパティを使用して、イベントを発生させたコントロールにアクセスすることもでき CommandSource ます。You can also access the control that raised the event by using the CommandSource property.

イベントを処理する方法の詳細については、次を参照してください。処理とイベントの発生します。For more information about how to handle events, see Handling and Raising Events.

適用対象

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