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GridView.PageCount Propriedade

Definição

Obtém o número de páginas necessárias para exibir os registros da fonte de dados em um controle GridView.

public:
 virtual property int PageCount { int get(); };
[System.ComponentModel.Browsable(false)]
public virtual int PageCount { get; }
[<System.ComponentModel.Browsable(false)>]
member this.PageCount : int
Public Overridable ReadOnly Property PageCount As Integer

Valor da propriedade

Int32

O número de páginas em um controle GridView.

Atributos

Exemplos

O exemplo a seguir demonstra como usar a PageCount propriedade para determinar o número total de páginas exibidas no GridView controle.


<%@ 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">

  protected void PageDropDownList_SelectedIndexChanged(Object sender, EventArgs e)
  {

    // Retrieve the pager row.
    GridViewRow pagerRow = CustomersGridView.BottomPagerRow;
    
    // Retrieve the PageDropDownList DropDownList from the bottom pager row.
    DropDownList pageList = (DropDownList)pagerRow.Cells[0].FindControl("PageDropDownList");

    // Set the PageIndex property to display that page selected by the user.
    CustomersGridView.PageIndex = pageList.SelectedIndex;

  }

  protected void CustomersGridView_DataBound(Object sender, EventArgs e)
  {

    // Retrieve the pager row.
    GridViewRow pagerRow = CustomersGridView.BottomPagerRow;
    
    // Retrieve the DropDownList and Label controls from the row.
    DropDownList pageList = (DropDownList)pagerRow.Cells[0].FindControl("PageDropDownList");
    Label pageLabel = (Label)pagerRow.Cells[0].FindControl("CurrentPageLabel");
        
    if(pageList != null)
    {
        
      // Create the values for the DropDownList control based on 
      // the  total number of pages required to display the data
      // source.
      for(int i=0; i<CustomersGridView.PageCount; i++)
      {
            
        // Create a ListItem object to represent a page.
        int pageNumber = i + 1;
        ListItem item = new ListItem(pageNumber.ToString());         
            
        // If the ListItem object matches the currently selected
        // page, flag the ListItem object as being selected. Because
        // the DropDownList control is recreated each time the pager
        // row gets created, this will persist the selected item in
        // the DropDownList control.   
        if(i==CustomersGridView.PageIndex)
        {
          item.Selected = true;
        }
            
        // Add the ListItem object to the Items collection of the 
        // DropDownList.
        pageList.Items.Add(item);
                
      }
        
    }
        
    if(pageLabel != null)
    {
        
      // Calculate the current page number.
      int currentPage = CustomersGridView.PageIndex + 1;     
        
      // Update the Label control with the current page information.
      pageLabel.Text = "Page " + currentPage.ToString() +
        " of " + CustomersGridView.PageCount.ToString();
        
    }    
    
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView PagerTemplate Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView PagerTemplate Example</h3>

      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSqlDataSource"   
        autogeneratecolumns="true"
        allowpaging="true"
        ondatabound="CustomersGridView_DataBound"  
        runat="server">
              
        <pagerstyle forecolor="Blue"
          backcolor="LightBlue"/>
              
        <pagertemplate>
          
          <table width="100%">                    
            <tr>                        
              <td style="width:70%">
                          
                <asp:label id="MessageLabel"
                  forecolor="Blue"
                  text="Select a page:" 
                  runat="server"/>
                <asp:dropdownlist id="PageDropDownList"
                  autopostback="true"
                  onselectedindexchanged="PageDropDownList_SelectedIndexChanged" 
                  runat="server"/>
                      
              </td>   
                      
              <td style="width:70%; text-align:right">
                      
                <asp:label id="CurrentPageLabel"
                  forecolor="Blue"
                  runat="server"/>
                      
              </td>
                                            
            </tr>                    
          </table>
          
        </pagertemplate> 
          
      </asp:gridview>
            
      <!-- 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="CustomersSqlDataSource"  
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
        runat="server">
      </asp:sqldatasource>
            
    </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">

    Protected Sub PageDropDownList_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
    
        ' Retrieve the pager row.
        Dim pagerRow As GridViewRow = CustomersGridView.BottomPagerRow
    
        ' Retrieve the PageDropDownList DropDownList from the bottom pager row.
        Dim pageList As DropDownList = CType(pagerRow.Cells(0).FindControl("PageDropDownList"), DropDownList)
        
        ' Set the PageIndex property to display that page selected by the user.
        CustomersGridView.PageIndex = pageList.SelectedIndex
    
    End Sub
    
    Protected Sub CustomersGridView_DataBound(ByVal sender As Object, ByVal e As EventArgs)
    
        ' Retrieve the pager row.
        Dim pagerRow As GridViewRow = CustomersGridView.BottomPagerRow
    
        ' Retrieve the DropDownList and Label controls from the row.
        Dim pageList As DropDownList = CType(pagerRow.Cells(0).FindControl("PageDropDownList"), DropDownList)
        Dim pageLabel As Label = CType(pagerRow.Cells(0).FindControl("CurrentPageLabel"), Label)
        
        If Not pageList Is Nothing Then
        
            ' Create the values for the DropDownList control based on 
            ' the  total number of pages required to display the data
            ' source.
            Dim i As Integer
            
            For i = 0 To CustomersGridView.PageCount - 1
            
                ' Create a ListItem object to represent a page.
                Dim pageNumber As Integer = i + 1
                Dim item As ListItem = New ListItem(pageNumber.ToString())
            
                ' If the ListItem object matches the currently selected
                ' page, flag the ListItem object as being selected. Because
                ' the DropDownList control is recreated each time the pager
                ' row gets created, this will persist the selected item in
                ' the DropDownList control.   
                If i = CustomersGridView.PageIndex Then
          
                    item.Selected = True
                
                End If
            
                ' Add the ListItem object to the Items collection of the 
                ' DropDownList.
                pageList.Items.Add(item)
                
            Next i
        
        End If
        
        If Not pageLabel Is Nothing Then
        
            ' Calculate the current page number.
            Dim currentPage As Integer = CustomersGridView.PageIndex + 1
        
            ' Update the Label control with the current page information.
            pageLabel.Text = "Page " & currentPage.ToString() & _
                " of " & CustomersGridView.PageCount.ToString()
        
        End If
    
    End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView PagerTemplate Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView PagerTemplate Example</h3>

      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSqlDataSource"   
        autogeneratecolumns="true"
        allowpaging="true"
        ondatabound="CustomersGridView_DataBound"  
        runat="server">
              
        <pagerstyle forecolor="Blue"
          backcolor="LightBlue"/>
              
        <pagertemplate>
          
          <table width="100%">                    
            <tr>                        
              <td style="width:70%">
                          
                <asp:label id="MessageLabel"
                  forecolor="Blue"
                  text="Select a page:" 
                  runat="server"/>
                <asp:dropdownlist id="PageDropDownList"
                  autopostback="true"
                  onselectedindexchanged="PageDropDownList_SelectedIndexChanged" 
                  runat="server"/>
                      
              </td>   
                      
              <td style="width:70%; text-align:right">
                      
                <asp:label id="CurrentPageLabel"
                  forecolor="Blue"
                  runat="server"/>
                      
              </td>
                                            
            </tr>                    
          </table>
          
        </pagertemplate> 
          
      </asp:gridview>
            
      <!-- 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="CustomersSqlDataSource"  
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
        runat="server">
      </asp:sqldatasource>
            
    </form>
  </body>
</html>

Comentários

Quando o recurso de paginação estiver habilitado (definindo a AllowPaging propriedade como true), use a PageCount propriedade para determinar o número total de páginas necessárias para exibir os registros na fonte de dados. Esse valor é calculado dividindo o número total de registros na fonte de dados pelo número de registros exibidos em uma página (conforme especificado pela PageSize propriedade) e arredondando para cima.

Aplica-se a

Confira também