ButtonFieldBase.CausesValidation 属性

定义

获取或设置一个值,该值指示在单击 ButtonFieldBase 对象中的按钮时是否执行验证。Gets or sets a value indicating whether validation is performed when a button in a ButtonFieldBase object is clicked.

public:
 virtual property bool CausesValidation { bool get(); void set(bool value); };
public virtual bool CausesValidation { get; set; }
member this.CausesValidation : bool with get, set
Public Overridable Property CausesValidation As Boolean

属性值

Boolean

如果为 true,则在单击 ButtonFieldBase 中的按钮时执行验证,否则为 falsetrue to perform validation when a button in a ButtonFieldBase is clicked; otherwise, false. 默认值为 falseThe default is false.

示例

下面的代码示例演示如何使用属性在 CausesValidation 控件的对象中单击按钮时执行验证 ButtonField GridViewThe following code example demonstrates how to use the CausesValidation property to perform validation when the button is clicked in the ButtonField object of a GridView control.

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

<script runat="server">

  void AuthorsGridView_RowCommand(Object sender, GridViewCommandEventArgs e)
  {
  
    // If multiple ButtonField columns are used, use the
    // CommandName property to determine which button was clicked.
    switch(e.CommandName)
    {
    
      case "Edit":
        AuthorsGridView.Columns[0].Visible = false;
        AuthorsGridView.Columns[1].Visible = true;
        break;
      case "Update":
        AuthorsGridView.Columns[0].Visible = true;
        AuthorsGridView.Columns[1].Visible = false;
        break;
      default:
        // Do nothing.
        break;
    }
    
  }
  
  void AuthorsGridView_RowUpdating (Object sender, GridViewUpdateEventArgs e)
  {
    
    // Retrieve the row being edited.    
    int index = AuthorsGridView.EditIndex;
    GridViewRow row = AuthorsGridView.Rows[index];
    
    // Retrieve the new value for the author's first name from the row. 
    // In this example, the author's first name is in the second cell 
    // of the row (index 1). To get the value, first retrieve the TextBox
    // that contains the value.
    TextBox firstNameTextBox = (TextBox)row.Cells[1].FindControl("FirstNameTextBox");
    
    // Make sure the control was found. 
    String firstName = "";    
    if(firstNameTextBox != null)
    {
      firstName = firstNameTextBox.Text;
    }
    
    // Retrieve the new value for the author's last name from the row. 
    // In this example, the author's last name is in the third cell 
    // of the row (index 2).
    TextBox lastNameTextBox = (TextBox)row.Cells[2].FindControl("LastNameTextBox");
    
    String lastName = "";
    if(lastNameTextBox != null)
    {
      lastName = lastNameTextBox.Text;
    }
    
    // Because custom TemplateField field columns are used, parameters 
    // are not automatically created and passed to the data source control.
    // Create Parameter objects to represent the fields to update and 
    // add the Parameter objects to the UpdateParameters collection.
    Parameter lastNameParameter = new Parameter("au_lname", TypeCode.String, lastName);   
    Parameter firstNameParameter = new Parameter("au_fname", TypeCode.String, firstName);
    
    // Clear the UpdateParameters collection before adding the 
    // Parameter objects. Otherwise, there will be duplicate
    // parameters.
    AuthorsSqlDataSource.UpdateParameters.Clear();
    AuthorsSqlDataSource.UpdateParameters.Add(lastNameParameter);
    AuthorsSqlDataSource.UpdateParameters.Add(firstNameParameter);
    
  }
    
</script>

<head runat="server">
    <title>ButtonFieldBase CausesValidation Example</title>
</head>
<body>
  <form id="form1" runat="server">
  <div>

    <h3>ButtonFieldBase CausesValidation Example</h3>

    <!-- Populate the Columns collection declaratively. -->
    <asp:gridview id="AuthorsGridView" 
      datasourceid="AuthorsSqlDataSource"
      cellpadding="5"  
      autogeneratecolumns="false"
      datakeynames="au_id" 
      onrowcommand="AuthorsGridView_RowCommand"
      onrowupdating="AuthorsGridView_RowUpdating"  
      runat="server">

      <columns>
        <asp:buttonfield commandname="Edit"
          causesvalidation="false" 
          text="Edit" 
          headertext="Edit Author">
        </asp:buttonfield>

        <asp:buttonfield commandname="Update" 
          visible="false" 
          causesvalidation="true" 
          text="Update"
          validationgroup="NameGroup" 
          headertext="Update Author">
        </asp:buttonfield>

        <asp:templatefield headertext="Last Name">
          <itemtemplate>
            <%# Eval("au_lname") %>
          </itemtemplate>

          <edititemtemplate>
            <asp:textbox id="LastNameTextBox"
              text='<%# Eval("au_lname") %>'
              width="175" 
              runat="server" /><br />  

            <asp:RequiredFieldValidator ID="LastNameRequiredValidator"
              ControlToValidate="LastNameTextBox"
              ErrorMessage="Please enter a last name."
              ValidationGroup="NameGroup" 
              Runat="server" />

          </edititemtemplate>
        </asp:templatefield>

        <asp:templatefield headertext="First Name">
          <itemtemplate>
            <%# Eval("au_fname") %>
          </itemtemplate>

          <edititemtemplate>
            <asp:textbox id="FirstNameTextBox"
              text='<%# Eval("au_fname") %>'
              width="175" 
              runat="server" /><br />  

            <asp:RequiredFieldValidator ID="FirstNameRequiredValidator"
              ControlToValidate="FirstNameTextBox"
              ErrorMessage="Please enter a first name."
              ValidationGroup="NameGroup" 
              Runat="server" />

          </edititemtemplate>

        </asp:templatefield>
      </columns>

    </asp:gridview>

    <!-- This example uses Microsoft SQL Server and connects -->
    <!-- to the Pubs sample database.                        -->
    <asp:sqldatasource id="AuthorsSqlDataSource"  
      selectcommand="SELECT [au_id], [au_lname], [au_fname] FROM [authors]"
      updatecommand="UPDATE authors SET au_lname=@au_lname, au_fname=@au_fname WHERE (authors.au_id = @au_id)"
      connectionstring="server=localhost;database=pubs;integrated security=SSPI"
      runat="server">   
    </asp:sqldatasource>

  </div>
  </form>
</body>
</html>


<%@ Page language="VB" %>

<script runat="server">

  Sub AuthorsGridView_RowCommand(ByVal sender As Object, ByVal e As GridViewCommandEventArgs)
  
    ' If multiple ButtonField columns are used, use the
    ' CommandName property to determine which button was clicked.
    Select Case e.CommandName
    
      Case "Edit"
        AuthorsGridView.Columns(0).Visible = False
        AuthorsGridView.Columns(1).Visible = True
      Case "Update"
        AuthorsGridView.Columns(0).Visible = True
        AuthorsGridView.Columns(1).Visible = False
      Case Else
        ' Do nothing.
   
    End Select
    
  End Sub
  
  Sub AuthorsGridView_RowUpdating(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs)
    
    ' Retrieve the row being edited.    
    Dim index As Integer = AuthorsGridView.EditIndex
    Dim row As GridViewRow = AuthorsGridView.Rows(index)
    
    ' Retrieve the new value for the author's first name from the row. 
    ' In this example, the author's first name is in the second cell 
    ' of the row (index 1). To get the value, first retrieve the TextBox
    ' that contains the value.
    Dim firstNameTextBox As TextBox = CType(row.Cells(1).FindControl("FirstNameTextBox"), TextBox)
    
    ' Make sure the control was found. 
    Dim firstName As String = ""
    If Not firstNameTextBox Is Nothing Then

      firstName = firstNameTextBox.Text
      
    End If
    
    ' Retrieve the new value for the author's last name from the row. 
    ' In this example, the author's last name is in the third cell 
    ' of the row (index 2).
    Dim lastNameTextBox As TextBox = CType(row.Cells(2).FindControl("LastNameTextBox"), TextBox)
    
    Dim lastName As String = ""
    If Not lastNameTextBox Is Nothing Then
    
      lastName = lastNameTextBox.Text
      
    End If
    
    ' Because custom TemplateField field columns are used, parameters 
    ' are not automatically created and passed to the data source control.
    ' Create Parameter objects to represent the fields to update and 
    ' add the Parameter objects to the UpdateParameters collection.
    Dim lastNameParameter As New Parameter("au_lname", TypeCode.String, lastName)
    Dim firstNameParameter As New Parameter("au_fname", TypeCode.String, firstName)
    
    ' Clear the UpdateParameters collection before adding the 
    ' Parameter objects. Otherwise, there will be duplicate
    ' parameters.
    AuthorsSqlDataSource.UpdateParameters.Clear()
    AuthorsSqlDataSource.UpdateParameters.Add(lastNameParameter)
    AuthorsSqlDataSource.UpdateParameters.Add(firstNameParameter)
    
  End Sub
    
</script>

<head runat="server">
    <title>ButtonFieldBase CausesValidation Example</title>
</head>
<body>
  <form id="form1" runat="server">
  <div>

    <h3>ButtonFieldBase CausesValidation Example</h3>

    <!-- Populate the Columns collection declaratively. -->
    <asp:gridview id="AuthorsGridView" 
      datasourceid="AuthorsSqlDataSource"
      cellpadding="5"  
      autogeneratecolumns="false"
      datakeynames="au_id" 
      onrowcommand="AuthorsGridView_RowCommand"
      onrowupdating="AuthorsGridView_RowUpdating"  
      runat="server">

      <columns>
        <asp:buttonfield commandname="Edit"
          causesvalidation="false" 
          text="Edit" 
          headertext="Edit Author">
        </asp:buttonfield>

        <asp:buttonfield commandname="Update" 
          visible="false" 
          causesvalidation="true" 
          text="Update"
          validationgroup="NameGroup" 
          headertext="Update Author">
        </asp:buttonfield>

        <asp:templatefield headertext="Last Name">
          <itemtemplate>
            <%# Eval("au_lname") %>
          </itemtemplate>

          <edititemtemplate>
            <asp:textbox id="LastNameTextBox"
              text='<%# Eval("au_lname") %>'
              width="175" 
              runat="server" /><br />  

            <asp:RequiredFieldValidator ID="LastNameRequiredValidator"
              ControlToValidate="LastNameTextBox"
              ErrorMessage="Please enter a last name."
              ValidationGroup="NameGroup" 
              Runat="server" />

          </edititemtemplate>
        </asp:templatefield>

        <asp:templatefield headertext="First Name">
          <itemtemplate>
            <%# Eval("au_fname") %>
          </itemtemplate>

          <edititemtemplate>
            <asp:textbox id="FirstNameTextBox"
              text='<%# Eval("au_fname") %>'
              width="175" 
              runat="server" /><br />  

            <asp:RequiredFieldValidator ID="FirstNameRequiredValidator"
              ControlToValidate="FirstNameTextBox"
              ErrorMessage="Please enter a first name."
              ValidationGroup="NameGroup" 
              Runat="server" />

          </edititemtemplate>

        </asp:templatefield>
      </columns>

    </asp:gridview>

    <!-- This example uses Microsoft SQL Server and connects -->
    <!-- to the Pubs sample database.                        -->
    <asp:sqldatasource id="AuthorsSqlDataSource"  
      selectcommand="SELECT [au_id], [au_lname], [au_fname] FROM [authors]"
      updatecommand="UPDATE authors SET au_lname=@au_lname, au_fname=@au_fname WHERE (authors.au_id = @au_id)"
      connectionstring="server=localhost;database=pubs;integrated security=SSPI"
      runat="server">   
    </asp:sqldatasource>

  </div>
  </form>
</body>
</html>

注解

使用验证组可以将页上的验证控件分配给特定类别。Validation groups allow you to assign validation controls on a page to a specific category. 每个验证组都可以独立于页面上的其他验证组进行验证。Each validation group can be validated independently of other validation groups on the page. 使用 ValidationGroup 属性指定 ButtonFieldBase 当对象回发到服务器时对其引发验证的验证组的名称。Use the ValidationGroup property to specify the name of the validation group for which the ButtonFieldBase object causes validation when it posts back to the server.

ValidationGroup仅当属性的值设置为时,属性才有效果 CausesValidation trueThe ValidationGroup property has an effect only when the value of the CausesValidation property is set to true. 如果为属性指定值,则 ValidationGroupButtonFieldBase 回发到服务器时,只会验证属于指定组的验证控件。When you specify a value for the ValidationGroup property, only the validation controls that are part of the specified group are validated when the ButtonFieldBase posts back to the server. 如果没有为属性指定值, ValidationGroup 并且 CausesValidation 属性设置为 true ,则当 ButtonFieldBase 回发到服务器时,将验证该页上未分配给验证组的所有验证控件。If you do not specify a value for the ValidationGroup property and the CausesValidation property is set to true, all validation controls on the page that are not assigned to a validation group are validated when the ButtonFieldBase posts back to the server.

此属性的值存储在视图状态中。The value of this property is stored in view state.

适用于

另请参阅