單項選擇題

You have an SQL query that takes one minute to execute. You use the following code segment to execute the SQL query asynchronously.Dim ar As IAsyncResult = cmd.BeginExecuteReader()You need to execute a method named DoWork() that takes one second to run while the SQL query is executing. DoWork() must run as many times as possible while the SQL query is executing. Which code segment should you use?（）

A. While ar.AsyncWaitHandle Is Nothing DoWork()End Whiledr = cmd.EndExecuteReader(ar)
B. While Not ar.IsCompleted DoWork()End Whiledr = cmd.EndExecuteReader(ar)
C. While T hread.CurrentThread.ThreadState = ThreadState.Running DoWork()End Whiledr = cmd.EndExecuteReader(ar)
D. While Not ar.AsyncWaitHandle.WaitOne() DoWork()End Whiledr = cmd.EndExecuteReader(ar)

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單項選擇題

You load an XmlDocument named doc with the following XML. World Atlas Dictionary You need to use an XPath query string to select the two book nodes. Which code segment should you use? （）

A. Dim root As XmlElement = doc.DocumentElementDim nodes As XmlNodeList = root.SelectNodes(".")
B. Dim root As XmlElement = doc.DocumentElementDim nodes As XmlNodeList = root.SelectNodes("book")
C. Dim root As XmlElement = doc.DocumentElementDim nodes As XmlNodeList = root.SelectNodes("bookstore//book")
D. Dim root As XmlElement = doc.DocumentElementDim nodes As XmlNodeList = root.SelectNodes("books/book")

單項選擇題

You create a Web Form. The Web Form uses the FormView control to enable a user to edit a record in the database. When the user clicks the Update button on the FormView control, the application must validate that the user has entered data in all of the fields. You need to ensure that the Web Form does not update if the user has not entered data in all of the fields. Which code segment should you use? （）

A. Protected Sub FormView1_ItemUpdating(ByVal sender As Object, _ ByVal e As System.Web.UI.WebControls.FormViewUpdateEventArgs) _ Handles FormView1.ItemUpdating Dim entry As DictionaryEntry For Each entry In e.Keys If entry.Value.ToString() = System.String.Empty Then e.Cancel = True Return End If Next entryEnd Sub
B. Protected Sub FormView1_ItemUpdated(ByVal sender As Object, _ ByVal e As System.Web.UI.WebControls.FormViewUpdatedEventArgs) _ Handles FormView1.ItemUpdated Dim entry As DictionaryEntry For Each entry In e.NewValues If entry.Value.Equals("") Then e.KeepInEditMode = True Return End If Next entryEnd Sub
C. Protected Sub FormView1_ItemUpdating(ByVal sender As Object, _ ByVal e As System.Web.UI.WebControls.FormViewUpdateEventArgs) _ Handles FormView1.ItemUpdating Dim entry As DictionaryEntry For Each entry In e.NewValues If entry.Value.Equals("") Then e.Cancel = True Return End If Next entryEnd Sub
D. Protected Sub FormView1_ItemUpdated(ByVal sender As Object, _ ByVal e As System.Web.UI.WebControls.FormViewUpdatedEventArgs) _ Handles FormView1.ItemUpdated Dim entry As DictionaryEntry For Each entry In e.Keys If entry.Value.ToString() = System.String.Empty Then e.KeepInEditMode = True Return End If Next entryEnd Sub