ServerDocument.IsCacheEnabled Method (2003 System)

Gets a value that indicates whether the specified document has a data cache.

Namespace:  Microsoft.VisualStudio.Tools.Applications.Runtime
Assembly:  Microsoft.VisualStudio.Tools.Applications.Runtime (in Microsoft.VisualStudio.Tools.Applications.Runtime.dll)

Syntax

'Declaration
Public Shared Function IsCacheEnabled ( _
    documentPath As String _
) As Boolean
'Usage
Dim documentPath As String
Dim returnValue As Boolean

returnValue = ServerDocument.IsCacheEnabled(documentPath)

public static bool IsCacheEnabled(
    string documentPath
)

Parameters

• documentPath
  Type: System.String
  The path of the document that you want to check.

Return Value

Type: System.Boolean
true if the specified document has a data cache; otherwise, false.

Exceptions

Exception	Condition
ArgumentNullException	The documentPath parameter is nulla null reference (Nothing in Visual Basic) or empty or consists entirely of white space characters.
FileNotFoundException	The file in documentPath does not exist.

Remarks

This method indicates only whether the document has a data cache, not whether the data cache actually contains data. If the document has a data cache that contains no data in it, this method still returns true.

Examples

The following code example creates a new ServerDocument, and then modifies data that is cached in the data island. The example first uses the IsCacheEnabled method to verify that the workbook has a data cache. This example requires a reference to the Microsoft.VisualStudio.Tools.Applications.Runtime assembly, and an Imports (for Visual Basic) or using (for C#) statement for the Microsoft.VisualStudio.Tools.Applications.Runtime namespace at the top of your code file.

Private customerOrdersSet As DataSet

Private Sub LoadCachedData(ByVal fileName As String)
    If ServerDocument.IsCacheEnabled(fileName) Then
        Dim serverDocument1 As ServerDocument = Nothing
        Try
            serverDocument1 = New ServerDocument(fileName)
            customerOrdersSet = New DataSet()

            ' Identify the namespace and the class that  
            ' contains the cached data object.
            Dim hostItem1 As CachedDataHostItem = _
                serverDocument1.CachedData.HostItems( _
                "DataCachingSource.ThisWorkbook")

            ' Identify the name of the cached data object.
            Dim dataItem1 As CachedDataItem = _
                hostItem1.CachedData("customerOrdersCached")

            ' Read the cached data into the local DataSet.
            If Nothing <> dataItem1.Xml AndAlso _
                Nothing <> dataItem1.Schema Then

                Dim xmlReader As New System.IO.StringReader( _
                    dataItem1.Xml)
                Dim schemaReader As New System.IO.StringReader( _
                    dataItem1.Schema)
                customerOrdersSet.ReadXmlSchema(schemaReader)
                customerOrdersSet.ReadXml(xmlReader)

                ' Modify the data.
                Dim row As DataRow
                For Each row In customerOrdersSet.Tables(0).Rows
                    Dim orders As Integer = Fix(row("OrderQuantity"))
                    row("OrderQuantity") = orders * 2
                Next row

                ' Write the modified data back to the
                ' cached data in the worksheet.
                dataItem1.SerializeDataInstance(customerOrdersSet)
                serverDocument1.Save()
            End If
        Finally
            If Not serverDocument1 Is Nothing Then
                serverDocument1.Close()
            End If
        End Try
    Else
        MsgBox("The specified document does not have " + _
            "a data cache.")
    End If
End Sub

private DataSet customerOrdersSet;

private void LoadCachedData(string fileName)
{
    if (ServerDocument.IsCacheEnabled(fileName))
    {
        ServerDocument serverDocument1 = null;
        try
        {
            serverDocument1 = new ServerDocument(fileName);
            customerOrdersSet = new DataSet();

            // Identify the namespace and the class that contains 
            // the cached data object.
            CachedDataHostItem hostItem1 =
                serverDocument1.CachedData.HostItems[
                "DataCachingSource.ThisWorkbook"];

            // Identify the name of the cached data object.
            CachedDataItem dataItem1 = hostItem1.CachedData[
                "customerOrdersCached"];

            // Read the cached data into the local DataSet.
            if (null != dataItem1.Xml && null != dataItem1.Schema)
            {
                System.IO.StringReader xmlReader =
                    new System.IO.StringReader(dataItem1.Xml);
                System.IO.StringReader schemaReader =
                    new System.IO.StringReader(dataItem1.Schema);
                customerOrdersSet.ReadXmlSchema(schemaReader);
                customerOrdersSet.ReadXml(xmlReader);

                // Modify the data.
                foreach (DataRow row in
                    customerOrdersSet.Tables[0].Rows)
                {
                    int orders = (int)row["OrderQuantity"];
                    row["OrderQuantity"] = orders * 2;
                }

                // Write the modified data back to the
                // cached data in the worksheet.
                dataItem1.SerializeDataInstance(customerOrdersSet);
                serverDocument1.Save();
            }
        }
        finally
        {
            if (serverDocument1 != null)
                serverDocument1.Close();
        }
    }
    else
    {
        MessageBox.Show("The specified document does not have " +
            "a data cache.");
    }
}

Permissions

• Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.

See Also

Reference

ServerDocument Class

ServerDocument Members

Microsoft.VisualStudio.Tools.Applications.Runtime Namespace