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WPF - Binding of TextBox in a Grid

Today we will talk about WPF and how we improve the loading time of our window. One of my colleague started to have a performance problem with an application written in WPF. The application has to run on some virtual machines with Windows and .NET 3.5
The application has a window with a grid that contains 200 cells. The model behind the view has an object with 50 property. I know we have too many properties, but this is the model, we need to optimize the loading time of the page and not to make a review.
public class MyModel : INotifyPropertyChanged
  public Foo Obj1 { get;  set ...}
public class FooModel : INotifyPropertyChanged
  public string P1 { get; set ... }
  public string P2 { get; set ... }
  public string P50 { get; set ... }
This model is bind to a grid that contains 4 columns and 50 rows. Each property is bind 4 times to the cell controller. The controller of the cell is a simple TextBox (this is a sample code).  The grid is similar to this:
                        <Grid.RowDefinitions> …  </Grid.RowDefinitions>
                        <Grid Grid.Row="0" Grid.Margin="10">
                            <TextBox Text="{Binding Path=DataObject.P11}" Grid.Row="1" Grid.Column="1"></TextBox>
                            <TextBox Text="{Binding Path=DataObject.P12}" Grid.Row="2" Grid.Column="1"></TextBox>
This is a simple binding, but on a virtual machine, under .NET 3.5, the loading time of this window is around 5-6 seconds. We need to find out what is the cause of this problem. After creating a sample project with this problem we discovered the cause of the problem.
It seems that the binding itself is very slow. If we compile the sample project with .NET 4.0 the loading time decreases a lot. But we cannot migrate to .NET 4.0. This is not an option now.
We could try to bind the grid to our model and each cell would be bind directly to the property.
<Grid Source= “Binding Path = DataObject”>
     <TextBox Text="{Binding P1}" Grid.Row="1" Grid.Column="1"></TextBox>
With this solution the performance is improved with ~1 second. We still have a problem, the windows is loading too slowly.
What we can do? The cause of the problem is the TextBox. The TextBox binding consumes a lot of resources.
Looking over the view we can replace the TextBox with a TextBlock. Running the application again and voila. The loading time of the page is under 1 second.  Before applying this solution we need to check if we need to have the text editable. The good news is NO DON’T NEED that option.
In our case, replacing the TextBox with TextBlock improved the loading time of the page with more then 5 seconds. If we need to have the text editable, then we could register to the click event and replace the TextBlock with a TextBox. To have the same UI, we added a border to the TextBlock also.
The things to remember from this story is to use the most simple and UI base controllers we need. We shouldn’t use a complicated UI controller if don’t need it. The more complicated they are, the more resources will need.


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