70-316 Developing and Implementing Windows-based Applications with Microsoft Visual C# .NET Practice Test

Demo Question 3.

You have been asked to build a Billing application for CKPowerHouse to bill its customers. You application must facilitate auditing. To do this, you create a form in your application that will allow users to modify data in the ElectricityBill table. You have created a DataSet object named dsElectricityBill. You perform these operations: 1. The data source of dsElectricityBill is ElectricityBill. 2. Your application will have two grids, gridEdit and gridOriginal. 3. The data source of gridEdit will be dsElectricityBill. 4. Users of your application will make changes to the data in dsElectricityBill through gridEdit. 5. When rows are modified in gridEdit, gridOriginal will display the original data of the modified rows. gridOriginal will display only rows that have been modified. 6. The data source of gridOriginal will be a DataView object named dvOriginal. Which of the following actions should you perform to provide this functionality in your application? (Each choice presents a part of the solution.) (Select 2 choices.)

A. Create dvOriginal with a clone of the dsElectricityBill data set.
B. Set the AllowPaging property of gridEdit to true.
C. Create dvOriginal with the dsElectricityBill data set.
D. Set the ViewState property of gridOriginal to DataViewRowState.ModifiedOriginal.
E. Set the RowStateFilter property of dvOriginal to DataViewRowState.ModifiedOriginal.


Display Answer

Answer: C, E In this scenario, you want to enable one grid, gridOriginal, to automatically detect data changes that occur in the other grid, gridEdit. To accomplish this, gridOriginal should use a DataView object that is created with the same DataSet used by gridEdit. Because the RowStateFilter property filters the rows that are available in a DataView object, you should set the RowStateFilter to DataViewRowState.ModifiedOriginal. Performing this action ensures that only the rows that have been modified will be displayed. The original data will be displayed in those rows. If the RowStateFilter property were set to DataViewRowState.ModifiedCurrent, then the current data of the modified rows would be displayed. The Clone method of a DataSet object creates a duplicate of the data set, but the clone contains no data. The ViewState property of the DataGrid Web control is used to maintain the grid's data between page requests and would not be used in the DataGrid control used on Windows forms. The AllowPaging property, when set to true, allows a data grid to display data in segments.

Explanation: