Grid with dynamic number of rows and columns, part 1
The post is devoted to the Wpf datagrid with cells that have defined fixed size but a number of rows and columns is updated dynamically in order to fill all available space. 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. In addition, in order to prevent too frequent changes of grid sizes if user are resizing window slowly, timer is used in application. The timer is created in constructor and starts or restarts each time one view height or view width are changed. 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. The DataGridCheckBoxColumn binds the check box control to a (nullable) boolean property of the data in the row that it is displaying.
Post as a guest
In this case, it would be a boolean property in the user data row, which represents the user to role assignment. Since there is no such property in the UserTable definition, another solution has to be implemented. Instead of binding to the check box control, a value converter is instantiated and bound to the DataGridCell that will contain the CheckBox control.
Using the Code
- This can be used in situations where the control is available, but an object cannot be accessed using standard application logic.
- It is a straight forward MVVM implementation where the dynamic column handling is done in the view-model layer.
- I’m making an image gallery of sorts, and I’m currently loading the images into a grid dynamically via C#.
- It must be easy to create the other columns as well, using the same logic that I used to create the Rows.
Every DataSet table has a set of events that can be used to get notified on data modifications.. This mechanism is used to add, remove and update the dynamic columns when the role table is modified. It is a good in-memory database with referential integrity, and it contains built-in notification delegates that publish the insertion, removal and modification of data rows. Its contents can be stored to an XML file, which is used as a persistence mechanism in this example. By turning off automatically generated columns using the AutoGenerateColumns property, you get full control of which columns are shown and how their data should be viewed and edited. As seen by the example of this article, this opens up for some pretty interesting possibilities, where you can completely customize the editor and thereby enhance the end-user experience.
How to dynamically change grid rows and columns according to window size in WPF
You can look at the WPF grid example in the image below, which shows a 10×5 grid table. The values for the number of rows and columns may change dynamically. For now, I just need to figure out how to wpf grid dynamic rows create this control dynamically. When the program starts, it needs to one time create this control, and then the size won’t change. You can find out how to use one on the DataGrid Class page on MSDN.
Common interface controls
However, there are something in .NET called Anonymous Types that you can use. This basically enables you to define an anonymous class at run time, so that you can define as many properties as you need columns. You can find out how to use them in the Anonymous Types (C# Programming Guide) page on MSDN.
If it was very wide, but not high, then it would only have one (or two, or however many are needed) row(s) and many columns. So now just need to figure out how to bind the columns to the IDictionary values. If you need WPF to populate datagrid, please refer to the following discussion on Microsoft’s https://traderoom.info/ Q&A blog. The Clear method of Grid.RowDefinitions deletes all rows ina Grid. The Add method of Grid.RowDefinitions adds a new row to aGrid. The Rows and Columns property of the UniformGrid are DependencyProperties, so you could bind them to properties on the DataContext to make them dynamic.
The only problem with a UniformGrid is it only arranges items Horizontally. If you want to display them Vertically, you can either create a custom UniformGrid, or switch to a different panel such as a WrapPanel. If you are new to WPF Panels, I would recommend reading through WPF Layouts – A Quick Visual Start. This grid will always have consecutive numbers, with a color rectangle in front of it. Clicking on the gray rectangle will change its color, and set the text to bold (I will deal with these triggers later).
I’m making an image gallery of sorts, and I’m currently loading the images into a grid dynamically via C#. If I shouldn’t be using a grid to display the images, I’m more than willing to change it to a better-suited control, but it needs to be window-resizing-friendly. Object tagging is the functionality that allows objects to be tagged to a control. This can be used in situations where the control is available, but an object cannot be accessed using standard application logic. In the case of this sample, the available control is the CheckBox in the DataGridCell and the required object is the role that corresponds to the column.
In this implementation, collection of cells is recreated each time if grid width or grid height is changed, and it leads to some application pauses. In the following post, this issue is solved with asynchronous method that updates cell array. Also, other implementation for cells could be used; for example, 2-dimensional array of cells ICellViewModels[][] works well.
