BoundColumn.DataFormatString 属性

定义

获取或设置指定列中各项的显示格式的字符串。Gets or sets the string that specifies the display format for items in the column.

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。A formatting string that specifies the display format of items in the column. 默认值为 EmptyThe default value is Empty.

示例

下面的示例演示如何使用 DataFormatString 属性为控件中的列指定各种格式 DataGridThe following example demonstrates how to use the DataFormatString property to specify various formats for the columns in the DataGrid control. Qty列的格式为整数, Price 列的格式设置为货币,列的 Weight 格式为十进制数字,列的 Expires 格式为短日期和时间字符串。The Qty column is formatted as an integer, the Price column is formatted as currency, the Weight column is formatted as a decimal number, and the Expires column is formatted as a short date and time string.


<%@ 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

使用 DataFormatString 属性为列中的项提供自定义格式。Use the DataFormatString property to provide a custom format for the items in the column.

数据格式字符串由以冒号分隔的两部分组成,格式为 { ABxx }。The data format string consists of two parts, separated by a colon, in the form { A : Bxx }. 例如,格式化字符串将 {0:F2} 显示具有两个小数位的定点数。For example, the formatting string {0:F2} displays a fixed-point number with two decimal places.

备注

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。The entire string must be enclosed in braces to indicate that it is a format string and not a literal string. 大括号外的任何文本都显示为文本。Any text outside the braces is displayed as literal text.

常规示例中冒号 (前面的值 A) 在从零开始的参数列表中指定参数索引。The value before the colon (A in the general example) specifies the parameter index in a zero-based list of parameters.

备注

此值只能设置为0,因为每个单元格中只有一个值。This value can only be set to 0 because there is only one value in each cell.

常规示例中冒号后面的字符 (B) 指定显示值的格式。The character after the colon (B in the general example) specifies the format to display the value in. 下表列出了常见格式。The following table lists the common formats.

格式字符Format character 说明Description
C 以货币格式显示数值。Displays numeric values in currency format.
D 以十进制格式显示数值。Displays numeric values in decimal format.
E 以科学 (指数) 格式显示数值。Displays numeric values in scientific (exponential) format.
F 以固定格式显示数值。Displays numeric values in fixed format.
G 以常规格式显示数值。Displays numeric values in general format.
N 以数字格式显示数值。Displays numeric values in number format.
X 以十六进制格式显示数值。Displays numeric values in hexadecimal format.

备注

格式字符不区分大小写,但除外 X ,后者在指定的情况下显示十六进制字符。The format character is not case-sensitive, except for X, which displays the hexadecimal characters in the case specified.

常规示例中格式字符 (后面的值 xx) 指定要显示的有效位数或小数位数。The value after the format character (xx in the general example) specifies the number of significant digits or decimal places to display.

有关设置字符串格式的详细信息,请参阅格式设置类型For more information on formatting strings, see Formatting Types.

适用于

另请参阅