BoundColumn.DataFormatString 属性

参考

定义

命名空间:: System.Web.UI.WebControls

程序集:: System.Web.dll

重要

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获取或设置指定列中各项的显示格式的字符串。

public:
 virtual property System::String ^ DataFormatString { System::String ^ get(); void set(System::String ^ value); };

public virtual string DataFormatString { get; set; }

member this.DataFormatString : string with get, set

Public Overridable Property DataFormatString As String

属性值

String

指定列中各项的显示格式的格式化字符串。默认值是 Empty。

示例

以下示例演示如何使用 DataFormatString 属性为控件中的 DataGrid 列指定各种格式。列 Qty 的格式设置为整数， Price 列的格式设置为货币， Weight 列的格式设置为十进制数， Expires 列的格式设置为短日期和时间字符串。


<%@ Page language="c#" AutoEventWireup="true" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Globalization" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
        <title>BoundColumn Example</title>
    </head>
       <script runat="server">
        // The Cart and CartView objects temporarily store the data source
        // for the DataGrid control while the page is being processed.
        DataTable Cart;
        DataView CartView;   
 
        void Page_Load(Object sender, EventArgs e) 
        {
            // With a database, use a select query to retrieve the data. 
            // Because the data source in this example is an in-memory 
            // DataTable, retrieve the data from session state if it exists; 
            // otherwise, create the data source.
            GetSource();

            // The DataGrid control maintains state between posts to the 
            // server; therefore it only needs to be bound to a data source 
            // the first time the page is loaded or when the data source 
            // is updated.
            if (!IsPostBack)
            {
                BindGrid();
            }
        }
 
        void ItemsGrid_Edit(Object sender, DataGridCommandEventArgs e) 
        {
            // Set the EditItemIndex property to the index of the item 
            // clicked in the DataGrid control to enable editing for that
            // item. Be sure to rebind the DateGrid to the data source 
            // to refresh the control.
            ItemsGrid.EditItemIndex = e.Item.ItemIndex;
            BindGrid();
        }
 
        void ItemsGrid_Cancel(Object sender, DataGridCommandEventArgs e) 
        {
            // Set the EditItemIndex property to -1 to exit editing mode.  
            // Be sure to rebind the DateGrid to the data source to 
            // refresh the control.
            ItemsGrid.EditItemIndex = -1;
            BindGrid();
        }
 
        void ItemsGrid_Update(Object sender, DataGridCommandEventArgs e) 
        {
            // Retrieve the updated values.
            // For bound columns, the edited value is stored in a TextBox.
            // The TextBox is the 0th control in a cell's Controls collection.
            // Each cell in the Cells collection of a DataGrid item represents
            // a column in the DataGrid control.
            DataGridItem updateItem = e.Item;

            TextBox qtyText = (TextBox)updateItem.Cells[2].Controls[0];
            TextBox priceText = (TextBox)updateItem.Cells[3].Controls[0];
            
            try {
                // Try to parse the updated values from the input text.
                Int32 newQty;
                Decimal newPrice;
            
                newQty = Int32.Parse(qtyText.Text, NumberStyles.Number);
                newPrice = Decimal.Parse(priceText.Text, NumberStyles.Currency);

                // Get the item cell value - "Item 1", "Item 2", etc.
                // For read-only columns, the value is stored in the cell text.
                String item = updateItem.Cells[1].Text;
       
                // With a database, use an update command to update the data. 
                // Because the data source in this example is an in-memory
                // DataTable, delete the old row and replace it with a new one.
    
                // Filter on the updated item, remove it,
                // then clear the row filter.
                CartView.RowFilter = "Item='" + item + "'";
                if (CartView.Count > 0)
                {
                    CartView.Delete(0);
                }
                CartView.RowFilter = "";
 
                // Add the updated entry for the item.
                DataRow dr = Cart.NewRow();
                dr["Item"] = item;
                dr["Qty"] = newQty;
                dr["Price"] = newPrice;
                dr["Weight"] = updateItem.Cells[4].Text;
                dr["Expires"] = updateItem.Cells[5].Text;
            
                Cart.Rows.Add(dr);
            }
            catch (System.FormatException)
            {
                // If parsing the price or quantity caused an 
                // exception, then leave edit mode without
                // changing any cell values.
            }

            // Set the EditItemIndex property to -1 to exit editing mode.  
            // Be sure to rebind the DataGrid to the data source to refresh
            // the control.
            ItemsGrid.EditItemIndex = -1;
            BindGrid();
        }
 
        void BindGrid() 
        {
            // Set the data source and bind to the Data Grid control.
            ItemsGrid.DataSource = CartView;
            ItemsGrid.DataBind();
        }

        void GetSource()
        {
            // For this example, the data source is a DataTable that is 
            // stored in session state.
            // If the data source does not exist, create it; otherwise, 
            // load the data.
            
            if (Session["ShoppingCart"] == null) 
            {     
                Cart = new DataTable();
                InitSource();
            } 
            else
            {
                // Retrieve the sample data from session state.
                Cart = (DataTable)Session["ShoppingCart"];
            }         
 
            // Create a DataView and specify the field to sort by.
            CartView = new DataView(Cart);
            CartView.Sort="Item";

            return;
        }
        
        void InitSource()
        {
            // Create the sample data.
 
            // Define the columns of the table.
            Cart.Columns.Add(new DataColumn("Qty", typeof(Int32)));
            Cart.Columns.Add(new DataColumn("Item", typeof(String)));
            Cart.Columns.Add(new DataColumn("Price", typeof(Decimal)));
            Cart.Columns.Add(new DataColumn("Weight", typeof(Decimal)));
            Cart.Columns.Add(new DataColumn("Expires", typeof(DateTime)));

            // Store the table in session state to persist its values 
            // between posts to the server.
            Session["ShoppingCart"] = Cart;
            
            // Populate the DataTable with sample data.
            DataRow dr;  

            for (int i = 1; i <= 4; i++) 
            {
                dr = Cart.NewRow();
                dr["Qty"] = i % 2 + 1;
                dr["Item"] = "Item " + i.ToString();
                dr["Price"] = (0.50 * (i + 1));
                dr["Weight"] = 5.0;
                dr["Expires"] = DateTime.Now + TimeSpan.FromDays(7);
                Cart.Rows.Add(dr);
            }
        }
        </script>
    <body>
        <form runat="server" id="form1">
            <h3>BoundColumn DataFormatString Example</h3>
            <asp:DataGrid id="ItemsGrid" 
                BorderColor="black" BorderWidth="1" CellPadding="3"
                OnEditCommand="ItemsGrid_Edit" OnCancelCommand="ItemsGrid_Cancel" 
                OnUpdateCommand="ItemsGrid_Update" AutoGenerateColumns="false"
                runat="server" >

                <HeaderStyle backcolor="#aaaadd"></HeaderStyle>

                <Columns>
                    <asp:EditCommandColumn EditText="Edit" CancelText="Cancel" 
                         UpdateText="Update" HeaderText="Edit Command Column">
                        <ItemStyle Wrap="False"></ItemStyle>
                        <HeaderStyle wrap="false"></HeaderStyle>
                    </asp:EditCommandColumn>

                    <asp:BoundColumn HeaderText="Item" DataField="Item" 
                                     ReadOnly="True" />

                    <asp:BoundColumn HeaderText="Quantity" DataField="Qty" 
                                     DataFormatString="{0:N0}"/>

                    <asp:BoundColumn HeaderText="Price" DataField="Price"
                                     DataFormatString="{0:c}" />

                    <asp:BoundColumn HeaderText="Weight" DataField="Weight" 
                                     ReadOnly="True" DataFormatString="{0:F3}" />

                    <asp:BoundColumn HeaderText="Expires" DataField="Expires" 
                                     ReadOnly="True" DataFormatString="{0:g}" />

                </Columns>
            </asp:DataGrid>
        </form>
    </body>
</html>


<%@ Page language="VB" AutoEventWireup="true" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Globalization" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
        <title>BoundColumn Example</title>
    </head>
    <script runat="server">
  
       ' The Cart and CartView objects temporarily store the data source 
       ' for the DataGrid control while the page is being processed.
       Dim Cart As DataTable
       Dim CartView As DataView   
 
       Sub Page_Load(sender as Object, e As EventArgs) 
 
          ' With a database, use a select query to retrieve the data. 
          ' Because the data source in this example is an in-memory 
          ' DataTable, retrieve the data from session state if it exists; 
          ' otherwise, create the data source.
          GetSource()

          ' The DataGrid control maintains state between posts to the 
          ' server; therefore it only needs to be bound to a data source 
          ' the first time the page is loaded or when the data source 
          ' is updated.
          If Not IsPostBack Then

             BindGrid()

          End If
                   
       End Sub
 
       Sub ItemsGrid_Edit(sender As Object, e As DataGridCommandEventArgs) 
 
          ' Set the EditItemIndex property to the index of the item 
          ' clicked in the DataGrid control to enable editing for that
          ' item. Be sure to rebind the DateGrid to the data source 
          ' to refresh the control.
          ItemsGrid.EditItemIndex = e.Item.ItemIndex
          BindGrid()
 
       End Sub
  
       Sub ItemsGrid_Cancel(sender As Object, e As DataGridCommandEventArgs) 
 
          ' Set the EditItemIndex property to -1 to exit editing mode.  
          ' Be sure to rebind the DateGrid to the data source to 
          ' refresh the control.
          ItemsGrid.EditItemIndex = -1
          BindGrid()
 
       End Sub
  
       Sub ItemsGrid_Update(sender As Object, e As DataGridCommandEventArgs) 
 
          ' Retrieve the updated values.
          ' For bound columns, the edited value is stored in a TextBox.
          ' The TextBox is the 0th control in a cell's Controls collection.
          ' Each cell in the Cells collection of a DataGrid item represents
          ' a column in the DataGrid control.
          Dim updateItem As DataGridItem
             updateItem = e.Item
 
          Dim qtyText As TextBox = CType(e.Item.Cells(2).Controls(0), TextBox)
          Dim priceText As TextBox = CType(e.Item.Cells(3).Controls(0), TextBox)
 
          Try 
              ' Try to parse the updated values from the input text.
              Dim newQty As Int32
              Dim newPrice As Decimal
             
              newQty = Int32.Parse(qtyText.Text, NumberStyles.Number)
              newPrice = Decimal.Parse(priceText.Text, NumberStyles.Currency)
 
              ' Get the item cell value - "Item 1", "Item 2", etc.
              ' For read-only columns, the value is stored in the cell text.
              Dim item As String = updateItem.Cells(1).Text
         
  
              ' With a database, use an update command to update the data. Because 
              ' the data source in this example is an in-memory DataTable, delete 
              ' the old row and replace it with a new one.
 
              ' Remove the old entry and clear the row filter.
              CartView.RowFilter = "Item='" & item & "'"
              If CartView.Count > 0 Then
             
                  CartView.Delete(0)
          
              End If
 
              CartView.RowFilter = ""
  
              ' Add the new entry.
              Dim dr As DataRow
              dr = Cart.NewRow()
 
              dr("Item") = item
              dr("Qty") = newQty
              dr("Price") = newPrice
              dr("Weight") = updateItem.Cells(4).Text
              dr("Expires") = updateItem.Cells(5).Text
              

              Cart.Rows.Add(dr)
          Catch ex As System.FormatException

             ' If parsing the price or quantity caused an 
             ' exception, then leave edit mode without
             ' changing any cell values.
          End Try
 
          ' Set the EditItemIndex property to -1 to exit editing mode. 
          ' Be sure to rebind the DateGrid to the data source to refresh
          ' the control.
          ItemsGrid.EditItemIndex = -1
          BindGrid()

       End Sub
 
       Sub BindGrid() 
       
          ' Set the data source and bind to the Data Grid control.
          ItemsGrid.DataSource = CartView
          ItemsGrid.DataBind()
 
       End Sub
 
       Sub GetSource()
 
          ' For this example, the data source will be a DataTable that is
          ' stored in session state.
          ' If the data source does not exist, create it; otherwise, 
          ' load the data.
          If Session("ShoppingCart") Is Nothing Then 
 
              Cart = New DataTable
              InitSource()
 
          Else
 
             ' Retrieve the sample data from session state.
             Cart = CType(Session("ShoppingCart"), DataTable)
 
          End If         
  
          ' Create a DataView and specify the field to sort by.
          CartView = New DataView(Cart)
          CartView.Sort="Item"
 
          Return
 
       End Sub
 
       Sub InitSource()
 
           ' Create the sample data.
  
           ' Define the columns of the table.
            Cart.Columns.Add(New DataColumn("Qty", GetType(System.Int32)))
            Cart.Columns.Add(New DataColumn("Item", GetType(System.String)))
            Cart.Columns.Add(New DataColumn("Price", GetType(System.Decimal)))
            Cart.Columns.Add(New DataColumn("Weight", GetType(System.Decimal)))
            Cart.Columns.Add(New DataColumn("Expires", GetType(System.DateTime)))

           ' Store the table in session state to persist its values 
           ' between posts to the server.
           Session("ShoppingCart") = Cart
             
           ' Populate the DataTable with sample data.
           ' The generated table row data look like this:

           Dim dr As DataRow
           Dim i As Integer

           For i = 1 to 4 
          
               dr = Cart.NewRow()
               dr("Qty") = i Mod 2 + 1
               dr("Item") = "Item " + i.ToString()
               dr("Price") = (0.5 * (i + 1))
               dr("Weight") = 5.0
               dr("Expires") = DateTime.Now + TimeSpan.FromDays(7)
               Cart.Rows.Add(dr)

           Next
       End Sub
    </script>
    <body>
        <form runat="server" id="form1">
            <h3>BoundColumn DataFormatString Example</h3>
            <asp:DataGrid id="ItemsGrid" 
                BorderColor="black" BorderWidth="1" CellPadding="3"
                OnEditCommand="ItemsGrid_Edit" OnCancelCommand="ItemsGrid_Cancel" 
                OnUpdateCommand="ItemsGrid_Update" AutoGenerateColumns="false"
                runat="server" >

                <HeaderStyle backcolor="#aaaadd"></HeaderStyle>

                <Columns>
                    <asp:EditCommandColumn EditText="Edit" CancelText="Cancel" 
                         UpdateText="Update" HeaderText="Edit Command Column">
                        <ItemStyle Wrap="False"></ItemStyle>
                        <HeaderStyle wrap="false"></HeaderStyle>
                    </asp:EditCommandColumn>

                    <asp:BoundColumn HeaderText="Item" DataField="Item" 
                                     ReadOnly="True" />

                    <asp:BoundColumn HeaderText="Quantity" DataField="Qty" 
                                     DataFormatString="{0:N0}"/>

                    <asp:BoundColumn HeaderText="Price" DataField="Price"
                                     DataFormatString="{0:c}" />

                    <asp:BoundColumn HeaderText="Weight" DataField="Weight" 
                                     ReadOnly="True" DataFormatString="{0:F3}" />

                    <asp:BoundColumn HeaderText="Expires" DataField="Expires" 
                                     ReadOnly="True" DataFormatString="{0:g}" />

                </Columns>
            </asp:DataGrid>
        </form>
    </body>
</html>

注解

DataFormatString使用属性为列中的项提供自定义格式。

数据格式字符串由两个部分组成，由冒号分隔，格式为 { A ： Bxx }。例如，格式设置字符串 {0:F2} 显示具有两个小数位数的定点数。

注意

整个字符串必须括在大括号中，以指示它是格式字符串，而不是文本字符串。大括号外的任何文本都显示为文本文本。

常规示例中冒号前的值 (A) 指定从零开始的参数列表中的参数索引。

注意

此值只能设置为 0，因为每个单元格中只有一个值。

常规示例中冒号后 (B 字符) 指定要显示值的格式。下表列出了常用格式。

设置字符格式	说明
`C`	以货币格式显示数值。
`D`	以十进制格式显示数值。
`E`	以科学 (指数) 格式显示数值。
`F`	以固定格式显示数值。
`G`	以常规格式显示数值。
`N`	以数字格式显示数值。
`X`	以十六进制格式显示数值。

注意

格式字符不区分大小写，但显示指定大小写中的十六进制字符除外 X。

常规示例中格式字符 (xx 的值) 指定要显示的有效位数或小数位数。

有关设置字符串格式的详细信息，请参阅格式设置类型。

适用于

通过

BoundColumn.DataFormatString 属性

定义

属性值

示例

注解

适用于

另请参阅

其他资源