单项选择题
A. Add a Web Control Library project to your solution. Define a class that inherits from CompositeControl.
B. Add a Windows Control Library project to your solution. Define a class that inherits from UserControl.
C. Add a Web User Control to your project. Define a class that inherits from UserControl.
D. Add a Mobile Web User Control to your project. Define a class that inherits from MobileUserControl..
多项选择题 You are creating a custom user control. The custom user control will be used on 10 Web Forms for an ASP.NET Web site that allows users to register and log on to a personalized experience. The custom user control uses two TextBox controls and two Button controls. You need to ensure that the controls are visible only when users are not logged on to the Web site. You also need to minimize the amount of effort in development and maintenance for the Web site. Which two actions should you perform?（）
单项选择题 You are creating a DataTable. You use the following code segment to create the DataTable. (Line numbers are included for reference only.) 01 Dim dt As New DataTable("Products") 02 dt.Columns.Add(New DataColumn("Price", _ GetType(Decimal))) 03 dt.Columns.Add(New DataColumn("Quantity", _ GetType(Int32))) 04 Dim dc As DataColumn = New DataColumn("Total", _ GetType(Decimal)) 05 dt.Columns.Add(dc) You need to ensure that the Total column is set to the value of the Price column multiplied by the Quantity column when new rows are added or changed. What should you do? （）
多项选择题 You are developing an application that connects to a Microsoft SQL Server database using the SqlConnection object. Your connection objects are being pooled. As the pool fills up, connection requests are queued. Some connection requests are rejected. You need to ensure that the application releases connections back to the pool as soon as possible. Also, you need to decrease the likelihood that connection requests will be rejected. Which three actions should you perform?（）