Number of child user controls that need to be populated in the parent user control are determined at run time and can change. The number of child user controls that need to be populated in the parent user control are determined at run time and can change. Then you just bind to Users collections and columns are autogenerated as you speficy them.
The Grid – Rows & columns
Once a control is created and its position within Grid isset, next step is to add control to Grid by using Grid.Children.Add method.This code snippet adds a TextBlock to Grid. The following code snippet adds three columns and three rowsto Grid. I have a child UserControl comprising of multiple textboxes, labels, image etc.
Data Handling
The ObjectTag itself is a DependencyProperty that can be attached to any type of control that is derived from DependencyObject. The CheckedBoxOnChecked method is called whenever the check box state is modified. The logic searches https://traderoom.info/ for the CheckBox’s DataGridCell and gets the user and role instances that belong to it. It will add or delete the user-role entry depending on the CheckBox.IsChecked state and whether a UserRoleRow is already present.
WPF Application
- You can find a detailed implementation of those properties on my blog.
- Then, on the .cs file of this page you must create a function with the code below.
- It is a straight forward MVVM implementation where the dynamic column handling is done in the view-model layer.
As was mentioned above, code of this post is based on code from previous post, so here we focus on new or changed code. The post is devoted to the Wpf datagrid with cells that has defined fixed size but number of rows and columns is updated dynamically in order to fill all available space. For example, such grid could be used in games at infinite 2D field or implementation of cellular automaton. In the previous post Wpf data grid is considered such that it has dynamically defined number of rows and columns but all cells has the same size. Dynamic grid is implemented as user control that contains DataGrid control bound to observable collection of collections of cell view models. There is an issue with binding to view size – as bindings are executed in single thread, new values of view width and height come in different moments.
Two DataGridTextColumns are instantiated for the first and the last name, and the cell content are bound to the data row through the binding to the row’s respective fields. wpf grid dynamic rows The data is kept in three tables in the UserRoleDataSet (Role, User and UserRole). The Role and User tables are bound to the data grid controls via a DataView.
This issue is solved by asynchronous method of updating current collection. Due to Wpf architecture and as dynamic grid user control item source is bound to Cells collection, all changes of this collection is done via Dispatcher. In the application priority DispatcherPriority.ApplicationIdle is used as it is executed after all data bindings, but other value could be used. Due to Wpf architecture and as dynamic grid user control item source is bound to Cells collection, all changes of this collection is done via Dispatcher. In the application priority DispatcherPriority.ApplicationIdle is used as it is executed after all data bindings, but other value could be used. After control size is changed and number of rows and columns of grid are calculated, cell set is recreated, but state of cells are preserved.
Also, other implementation for cells could be used, for example, 2-dimensional array of cells ICellViewModels[][] works well. After new cells set is created, collection of cell view models should be updated. In the previous post, this collection was recreated each time and it leads to application hangs.
View model for each cell implements ICellViewModel interface that defines property for data model that implements ICell interface and command for changing state for the cell. For now, I just need to figure out how to create this control dynamically. When the program starts, it needs to one time create this control, and then the size won’t change. This article shows an implementation of dynamic column handling for WPF DataGrid controls. It is a straight forward MVVM implementation where the dynamic column handling is done in the view-model layer. The drawback of this solution is that GUI components spilled over into the ViewModel layer.
As an added bonus (and to prevent extra state logic) I added the functionality that the CheckBox control is not shown in the user data grid new item row. The DataGridCheckBoxColumn style has to be modified, and the Visibility flag of the CheckBox has to be set, depending on the contents of the DataGridCell. If the data row is the new item row, then it has a NewItemPlaceHolder.
The data model of this sample consists of a User and a Role table, and a UserRole table that is the correlation table between the other two tables. An entry in the UserRole table means that the user (referenced by its user id) has a role assigned (referenced by the role’s id). If there is no entry for a certain user-role combination, then that means that the user in question does not have the corresponding role assigned. In this example, we have simply divided the available space into two columns, which will share the space equally, using a “star width” (this will be explained later). On the second button, I use a so-called Attached property to place the button in the second column (0 is the first column, 1 is the second and so on).