Preparing for a . NET Datagrid interview? This complete guide, which draws from CareerRide and YouTube, gives you 25 important questions and detailed answers to help you ace your interview.
1 What is the purpose of using the DataGrid control?
Answer: The DataGrid control is a powerful tool for displaying and manipulating tabular data in .NET applications. It offers a visually appealing and interactive way to present information, enhancing user experience and simplifying data interaction.
2 What are the different types of columns that exist in DataGrid?
Answer DataGrid supports various column types including
- Bound columns: These columns display data directly from a data source, such as a database or a dataset.
- Template columns: These columns allow you to customize the display and editing of data using templates.
- Button columns: These columns provide buttons within the grid, enabling users to perform actions on the displayed data.
- CheckBox columns: These columns allow users to select rows by clicking checkboxes.
- HyperLink columns: These columns display hyperlinks within the grid, enabling users to navigate to other resources.
3 How can the appearance be controlled in DataGrid?
Answer: You can control the appearance of the DataGrid using various properties, such as:
- Font: Set the font style, size, and color for the grid’s text.
- ForeColor: Set the foreground color for the grid’s text.
- BackColor: Set the background color for the grid’s cells.
- AlternatingRowColor: Set the background color for alternating rows.
- GridLines: Control the visibility and style of grid lines.
- HeaderStyle: Customize the appearance of the header row.
4. What is the procedure followed to add attributes in the <tr> tag?
Answer To add attributes to the <tr> tag in DataGrid, you can use the Attributes property of the DataGridItem class This property allows you to specify key-value pairs that define the attributes for the row
5. What’s the difference between the System.Web.UI.WebControls.DataGrid and System.Windows.Forms.DataGrid?
Answer: The key difference lies in the platforms they are used for:
- System.Web.UI.WebControls.DataGrid: This control is used in ASP.NET web applications to display data on web pages.
- System.Windows.Forms.DataGrid: This control is used in Windows Forms applications to display data in desktop applications.
6. How do you display an editable drop-down list in DataGrid?
Answer: To display an editable drop-down list in DataGrid, you can use a template column with a DropDownList control inside the template. This allows users to select values from a predefined list and edit them directly within the grid.
7. What tasks are involved after the drop-down list is created?
Answer: After creating the drop-down list, you need to:
- Populate the list with items: Add the desired values to the drop-down list.
- Handle events: Implement event handlers for events like selection changed and item databound to manage user interactions.
- Bind the list to a data source: If applicable, connect the drop-down list to a data source to dynamically populate it with data.
8. Write a program to manually define the columns in .NET DataGrid?
Answer: To manually define columns in .NET DataGrid, you can use the Columns collection of the DataGrid control. This collection allows you to add columns of different types and customize their properties.
9. Write a program to show different selection modes in DataGrid?
Answer: The DataGrid control supports various selection modes, including:
- Single selection: Only one row can be selected at a time.
- Multiple selection: Multiple rows can be selected simultaneously.
- None: No rows can be selected.
You can set the SelectionMode property of the DataGrid control to specify the desired selection mode.
10. Write a program to do column sorting, reordering, and resizing?
Answer: The DataGrid control allows users to sort, reorder, and resize columns. You can enable these features by setting the AllowSorting, AllowColumnReorder, and AllowColumnResize properties of the DataGrid control to true.
11. How does binding work in DataGrid?
Answer: DataGrid supports data binding, which connects the grid to a data source. This enables the grid to display and manipulate data from the source. You can use various data sources, including datasets, data tables, and collections.
12. Write a program to display the use of multiple columns in DataGrid?
Answer: To display multiple columns in DataGrid, you can add columns to the Columns collection of the DataGrid control. Each column can be bound to a different data field in the data source.
13. What are the ways that properties can be shown in DataGrid?
Answer: Properties can be shown in DataGrid using bound columns, template columns, or custom controls. Bound columns display data directly from the data source, while template columns allow you to customize the display and editing of data using templates. Custom controls provide even greater flexibility for displaying and manipulating data.
14. Write a program that adds two columns bound with the same properties and having column headings using XAML?
Answer: In XAML, you can add two columns bound to the same properties using the DataGridTextColumn element. You can set the Header property of each column to specify the desired column headings.
15. What is the purpose of External IEnumerables used in DataGrid?
Answer: External IEnumerables are used in DataGrid to provide a way to display data from a large data source without loading the entire data set into memory. This improves performance and scalability when dealing with large amounts of data.
16. How is it possible to edit the data in DataGrid?
Answer: DataGrid supports data editing through various mechanisms, including:
- Cell editing: Users can directly edit cell values within the grid.
- Row editing: Users can edit entire rows at once.
- Programmatic editing: You can write code to edit data in the grid programmatically.
17. What is the difference between Windows Forms and Web Forms DataGrid control?
Answer: The main difference lies in the platforms they are used for:
- Windows Forms DataGrid: This control is used in Windows Forms applications to display data in desktop applications.
- Web Forms DataGrid: This control is used in ASP.NET web applications to display data on web pages.
18. Write a program to control the column width, height, and alignment of DataGrid?
Answer: You can control the column width, height, and alignment using the Width, Height, and HorizontalAlignment properties of the DataGridColumn class. These properties allow you to customize the layout of the grid columns.
19. What are the ways in which functionalities can be added to DataGrid control data source?
Answer: You can add functionalities to the DataGrid control data source using various methods, including:
- Data source events: Handle events like DataBindingComplete and ListChanged to perform actions when the data source changes.
- Custom data source classes: Create custom data source classes that implement the IBindingList or IList interfaces to add specific functionalities.
- Data source extensions: Use extension methods to add custom functionalities to existing data source classes.
20. Why is the update strategy not preferred to be used in DataGrid control?
Answer: The update strategy is not preferred in DataGrid control because it can lead to performance issues when dealing with large data sets. It involves loading the entire data set into memory and updating it all at once, which can be slow and resource-intensive.
21. What is the difference between DataGrid, DataList, and Repeater?
Answer: These three controls are used to display tabular data in ASP.NET web applications, but they differ in their features and capabilities:
- DataGrid: Offers the most comprehensive feature set, including data binding, sorting, filtering, editing, and paging.
- DataList: Provides a simpler way to display tabular data with limited features compared to DataGrid.
- Repeater: The most basic control, offering only data binding and limited formatting options.
22. What tag do you use to add a hyperlink column to the DataGrid?
Answer: You can use the HyperLinkColumn element in XAML to add a hyperlink column to the DataGrid. This element allows you to specify the URL and text for the hyperlinks.
23. Write ADO.NET code showing Dataset storing multiple tables?
Answer: To create an ADO.NET Dataset storing multiple tables, you can use the DataSet class and add DataTable objects to the Tables collection. Each DataTable represents a table in the dataset.
24. What is the difference between a dataset and a data reader?
Answer: The main difference lies in how they handle data:
- Dataset: Loads the entire data set into memory, providing a disconnected view of the data.
- Data reader: Reads data from a data source one row at a time, providing a connected view of the data.
25. What is a Dataset object? Explain the various objects in a Dataset.
HARD React Interview Questions (3 patterns)
FAQ
What is a component in React interview questions?
What is JSX in React interview questions?
What is virtual dom in React interview questions?
How to use DataGrid component in ReactJS?
We can use the following approach in ReactJS to use DataGrid Component. Creating React Application And Installing Module: Project Structure: It will look like the following. Example: Now write down the following code in the App.js file. Here, App is our default component where we have written our code.
Is repeater better than GridView?
This is mostly because of the DataReader class, which is used for read-only access. DataReader is faster than DataSet or DataTable classes commonly used with GridView. Compared to GridView and DataList control, Repeater has limited features. By default, Repeater is good for displaying data. It is not the best choice if you need editing of data.
What are the most common ASP NET interview questions?
Some of the most common ASP.NET interview questions include: What is ASP.NET? What are the benefits of ASP.NET? What are the different types of ASP.NET applications?
