DataGridViewComboBoxColumn in Windows Forms allows users to select a value from a drop-down list in each row of a DataGridView control. This is a useful feature for displaying and selecting data in a tabular format. However, what if we want to add different items to the drop-down list in each row? In this article, we will explore how to achieve this functionality.
To begin with, let's create a Windows Forms application and add a DataGridView control to it. Next, we will add a DataGridViewComboBoxColumn to the grid by right-clicking on the grid and selecting "Add Column" option. This will open a dialog box where we can select the column type as DataGridViewComboBoxColumn. Click on "Add" to add the column to the grid.
Now, we need to populate the drop-down list of the DataGridViewComboBoxColumn with items. We can do this by setting the DataSource property of the column to a list of items. For example, let's say we want to add different food items to the drop-down list in each row. We can create a list of food items and set it as the DataSource of the column.
Next, we need to set the DisplayMember and ValueMember properties of the column. The DisplayMember property specifies which property of the items in the list should be displayed in the drop-down list. In our case, it can be the name of the food item. The ValueMember property specifies which property of the items should be used as the value when an item is selected. In this case, we can use the food item's ID as the value.
Now, we need to specify which food items should be added to the drop-down list in each row. To do this, we can handle the DataGridView's CellFormatting event. This event is fired for each cell when it is being formatted for display. We can use this event to add items to the drop-down list based on the row index.
First, we need to check if the current cell belongs to the DataGridViewComboBoxColumn. If it does, we can cast the cell's owning column to DataGridViewComboBoxColumn and access its Items collection. We can then add the desired items to this collection based on the row index.
For example, let's say we want to add pizza to the drop-down list in the first row, burger in the second row, and tacos in the third row. We can achieve this by checking the row index in the CellFormatting event and adding the appropriate item to the Items collection.
Finally, we need to handle the DataGridView's CellValueChanged event to retrieve the selected item from the drop-down list. We can access the selected item's ID from the Value property of the cell and perform any necessary operations based on it.
In conclusion, by handling the CellFormatting event and setting the DataSource, DisplayMember, and ValueMember properties of the DataGridViewComboBoxColumn, we can add different items to the drop-down list in each row of a DataGridView control. This is a useful feature for scenarios where we need to display and select different types of data in a tabular format.
