BaseDataList.IsBindableType(Type) Método
Definición
Importante
Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.
Determina si el tipo de datos especificado se puede enlazar a un control de lista derivado de la clase BaseDataList.
public:
static bool IsBindableType(Type ^ type);public static bool IsBindableType (Type type);static member IsBindableType : Type -> boolPublic Shared Function IsBindableType (type As Type) As BooleanParámetros
Devoluciones
Es true si el tipo de datos especificado se puede enlazar a un control de lista derivado de la clase BaseDataList; en caso contrario, es false.
Ejemplos
En el ejemplo de código siguiente se muestra cómo usar la IsBindableType propiedad para determinar si los valores de un tipo de datos determinado se pueden enlazar a un DataGrid control .
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<!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" >
<script runat="server">
DataView CreateDataSource()
{
// Create sample data for the DataGrid control.
DataTable dt = new DataTable();
DataRow dr;
// Define the columns of the table.
dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
// Populate the table with sample values.
for (int i = 0; i < 9; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + i.ToString();
dr[2] = 1.23 * (i + 1);
dt.Rows.Add(dr);
}
DataView dv = new DataView(dt);
return dv;
}
void Page_Load(Object sender, EventArgs e)
{
// Load sample data only once when the page is first loaded.
if (!IsPostBack)
{
// Retrieve sample data.
DataView Source = CreateDataSource();
// Bind the data source to the DataGrid control if each column
// in the data source contains a data type that is compatible
// with the DataGrid; otherwise, display an error message.
if(ValidateSourceTypes(Source))
{
ItemsGrid.DataSource = Source;
ItemsGrid.DataBind();
}
else
{
Message.Text = "The data source is not compatible with the DataGrid control.";
}
}
}
bool ValidateSourceTypes(DataView Source)
{
// Test the data type of each column in the data source to make
// sure it is compatible with the DataGrid control.
// Initialize the success flag to true.
bool Success = true;
// Iterate through each column of the data source and test the
// data type for compatibility with the DataGrid control.
foreach(DataColumn column in Source.Table.Columns)
{
if(!BaseDataList.IsBindableType(column.DataType))
{
Success = false;
}
}
return Success;
}
</script>
<head runat="server">
<title>BaseDataList IsBindableType Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>BaseDataList IsBindableType Example</h3>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
GridLines="Both"
AutoGenerateColumns="true"
runat="server">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
</asp:DataGrid>
<br /><br />
<asp:Label id="Message"
runat="server"/>
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<!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" >
<script runat="server">
Function CreateDataSource() As ICollection
' Create sample data for the DataGrid control.
Dim dt As DataTable = New DataTable()
Dim dr As DataRow
' Define the columns of the table.
dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
dt.Columns.Add(New DataColumn("StringValue", GetType(string)))
dt.Columns.Add(New DataColumn("CurrencyValue", GetType(double)))
' Populate the table with sample values.
Dim i As Integer
For i = 0 to 8
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " & i.ToString()
dr(2) = 1.23 * (i + 1)
dt.Rows.Add(dr)
Next i
Dim dv As DataView = New DataView(dt)
Return dv
End Function
Sub Page_Load(sender As Object, e As EventArgs)
' Load sample data only once when the page is first loaded.
If Not IsPostBack Then
' Retrieve sample data.
Dim Source As DataView = CreateDataSource()
' Bind the data source to the DataGrid control if each column in
' the data source contains a data type that is compatible with the
' DataGrid; Otherwise, display an error message.
If ValidateSourceTypes(Source) Then
ItemsGrid.DataSource = Source
ItemsGrid.DataBind()
Else
Message.Text = "The data source is not compatible with the DataGrid control."
End If
End If
End Sub
Function ValidateSourceTypes(Source As DataView) As Boolean
' Test the data type of each column in the data source to make
' sure it is compatible with the DataGrid control.
' Initialize the success flag to True.
Dim Success As Boolean = True
' Iterate through each column of the data source and test the
' data type for compatibility with the DataGrid control.
Dim column As DataColumn
For Each column In Source.Table.Columns
If Not BaseDataList.IsBindableType(column.DataType) Then
Success = False
End If
Next
Return Success
End Function
</script>
<head runat="server">
<title>BaseDataList IsBindableType Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>BaseDataList IsBindableType Example</h3>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
GridLines="Both"
AutoGenerateColumns="true"
runat="server">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
</asp:DataGrid>
<br /><br />
<asp:Label id="Message"
runat="server"/>
</form>
</body>
</html>
Comentarios
Utilice el IsBindableType método estático para determinar si el tipo de datos especificado se puede enlazar a un control de lista que hereda de la BaseDataList clase . Los tipos de datos admitidos son System.Boolean, System.Byte, System.SByte, System.Int32System.UInt16System.Int64System.UInt64System.CharSystem.UInt32System.Int16System.SingleSystem.DateTimeSystem.DoubleSystem.Decimaly .System.String
Se aplica a
Consulte también
Comentarios
Próximamente: A lo largo de 2024 iremos eliminando gradualmente GitHub Issues como mecanismo de comentarios sobre el contenido y lo sustituiremos por un nuevo sistema de comentarios. Para más información, vea: https://aka.ms/ContentUserFeedback.
Enviar y ver comentarios de