The second grid doesn't declare any columns in the ASPX page. They're added programmatically in the code-behind page, as you'll see in a moment. Figure 5 lists the different kinds of column types you may use with a DataGrid.
If all you want to do is show your data in rows and columns, you can install a table-oriented DataSource in your DataGrid and stop there. NET will automatically iterate through the table rows and show them.
But it's often useful to add some interactive functionality to the DataGrid. Figure 6 shows the skeleton code for managing the DataGrid. I'll go over each piece in detail. The first step in programming a DataGrid is to set up its DataSource property. There are several ways to establish a DataSource. For most real-world applications, you'd probably use a SqlConnection object and a SqlCommand object to create a DataReader representing the database.
I'll look at integrating ADO. NET in a future column. Then CreateDataSource makes a DataView object out of the table and returns the DataView, where it is bound to the controls when the page loads. SelectedItemsGrid's columns are added programmatically. These steps are necessary to make the grid bind automatically. The loading code also adds a button column. There's no reason the columns have to be added programmatically—I just did it this way to show it can be done.
The button column within the InventoryGrid is useless without a command handler. Item property includes the row of data selected by the user represented by TableCells.
If the command name the ID of the control generating the command event is Add, this method creates a new row and adds it to the SelectedItemsGrid. Of course, users would probably also like to deselect items as when removing items from a shopping cart. The SelectedItemsGrid includes a button column for removing items from the grid. Figure 8 shows the command handler for the SelectedItemsGrid. Removing the item requires you to set up a filter to find the row that includes the product number.
Once you find the row, you may delete it. As mentioned earlier, another alternative for displaying data is the DataList. A CheckBoxField can only display a single checkbox, whereas an ImageField can only display a single image. What if a particular field needs to display some text, a checkbox, and an image, all based upon different data field values?
Furthermore, the BoundField limits its display to a single data field. What if we wanted to show two or more data field values in a single GridView column?
To accommodate this level of flexibility the GridView offers the TemplateField, which renders using a template. Furthermore, the TemplateField has a variety of templates that can be used to customize the rendering for different situations. For example, the ItemTemplate is used by default to render the cell for each row, but the EditItemTemplate template can be used to customize the interface when editing data.
In the preceding tutorial we saw how to customize the formatting based on the underlying data using the DataBound and RowDataBound event handlers. Another way to customize the formatting based on the underlying data is by calling formatting methods from within a template.
We'll look at this technique in this tutorial as well. For this tutorial we will use TemplateFields to customize the appearance of a list of employees. Specifically, we'll list all of the employees, but will display the employee's first and last names in one column, their hire date in a Calendar control, and a status column that indicates how many days they've been employed at the company.
In reporting scenarios where you need to use TemplateFields to customize the appearance, I find it easiest to start by creating a GridView control that contains just BoundFields first and then to add new TemplateFields or convert the existing BoundFields to TemplateFields as needed.
Therefore, let's start this tutorial by adding a GridView to the page through the Designer and binding it to an ObjectDataSource that returns the list of employees. These steps will create a GridView with BoundFields for each of the employee fields. Open the GridViewTemplateField. To remove these BoundFields you can:. Take a moment to view our progress in a browser. At this point you should see a table with a record for each employee and four columns: one for the employee's last name, one for their first name, one for their title, and one for their hire date.
Currently, each employee's first and last names are displayed in a separate column. It might be nice to combine them into a single column instead. To accomplish this we need to use a TemplateField. Both approaches net the same result, but personally I like converting BoundFields to TemplateFields when possible because the conversion automatically adds an ItemTemplate and EditItemTemplate with Web controls and databinding syntax to mimic the appearance and functionality of the BoundField.
The benefit is that we'll need to do less work with the TemplateField as the conversion process will have performed some of the work for us. Select the BoundField to convert from the list in the lower left corner and then click the "Convert this field into a TemplateField" link in the bottom right corner.
After this change there's no perceptive difference in the Designer. This can be accomplished either by hand or through the Designer.
To do it by hand, simply add the appropriate declarative syntax to the ItemTemplate :. This will display the GridView's template editing interface. Html Editor. Featured Shapes. Custom Shapes. Document Capabilities. User Interaction. Area Charts. Bar Charts. Doughnut Charts. Financial Charts. Line Charts. Pie Charts. Point Charts.
Polar and Radar Charts. Range Charts. Sparkline Charts. Tree Map. Funnel and Pyramid Charts. More Features. UI Customization. Bar Gauge. Circular Gauge. Linear Gauge. Tab Panel. User posted Hi to All, Good day! Parse DataBinder. Eval Container. DataItem, "TotalOvertime" Mod CancelCommand dgOvertime. But if I will enable it, the following error will occur: Failed to load viewstate.
The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.
Clear 'Do counter for binding hours. Add New ListItem intCntr. Clear 'Do counter for binding minutes. Tuesday, September 23, AM. User posted Hi van. Because it is more flexible.
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