WPF DataGrid is very slow to render

问题:

I have tried using both a customized DataGrid as well as the stock one in WPF. I have tried populating them manually as well as through bindings. In both cases they are slow.

I have a scenerio where the user clicks on a button and a DataGrid appears with appropriate data. Currently I am in proof of concept mode and just using sample data. I have a DataSet with a table that has 10 rows in it.

If I don't attach any data to the DataGrid when I click the button the empty DataGrid displays pretty much instantly, a user cannot perceive a delay. As soon as I add 10 rows of data, for 6 columns, the delay is about 2 seconds, very noticable to the user.

I even tried filling with empty data, just to get an empty grid to appear and it is equally as slow.

for (int i = 0; i < 10; i++)
    _dataGrid.Items.Add("");

I put a timer to count the ticks from when the button is clicked to when all of the code is executed to draw the DataGrid and it is around 20 milliseconds, so the code executes very fast, but on the screen is where the big lag is. I tried a GridView and it renders much fast on the screen.

I have heard various reports of slow DataGrid drawing with complex scenarios and using 1000's of rows, but this is as simple as it gets, 6 columns by 10 rows filled with empty data.

For readonly display is GridView an equally viable option to the DataGrid?

---

Update

Here is the creation of my columns.

                DataGridTextColumn column = new DataGridTextColumn();
                column.ColumnWidthChanged += new ColumnWidthChangedEventHandler(column_ColumnWidthChanged);

                column.Header = entity.GetPropertyValue("ColumnLabel");
                column.Binding = new Binding(entity.GetPropertyValue("Tag"));
                column.Width = new DataGridLength(entity.GetPropertyDouble("DisplaySize"));
                _dataGrid.Columns.Add(column);

This is a how I bind the DataSet with 10 rows in it.

                _dataGrid.ItemsSource = ds.Tables[0].DefaultView;
                _dataGrid.DataContext = ds.Tables[0];

Not sure what I can do differently.

回答1:

Are you have:

• Enabled VirtualizingStackPanel.VirtualizationMode for a Grid? if not - try to set.
• Set VirtualizingStackPanel.IsVirtualizing="true" for DataGrid
• Wrapped up a Grid by a StackPanel container? If yes - try to remove.
• Wrapped up a Grid by an external ScrollViewer control? If yes - try to remove.

One more point, could you bind whole items collection at once instead of adding each item into the grid.Items collection?

回答2:

A general tip for DataGrid performance issues: I had a problem with the DataGrid in which it took literally seconds to refresh after a window resize, column sort, etc. and locked up the window UI while it was doing so (1000 rows, 5 columns).

It came down to an issue (bug?) with the WPF sizing calculations. I had it in a grid with the RowDefinition Height="Auto" which was causing the rendering system to try and recalculate the size of the DataGrid at runtime by measuring the size of each and every column and row, presumably by filling the whole grid (as I understand it). It is supposed to handle this intelligently somehow but in this case it was not.

A quick check to see if this is a related problem is to set the Height and Width properties of the DataGrid to a fixed size for the duration of the test, and try running again. If your performance is restored, a permanent fix may be among these options:

• Change the sizes of the containing elements to be relative (*) or fixed values
• Set MaxHeight and MaxWidth of the DataGrid to a fixed value larger than it could get in normal use
• Try another container type with different resizing strategy (Grid, DockPanel, etc)

回答3:

A blog I found on Google gave me a sort-of solution. As the author said, I disabled GroupStyle, and the rendering speed issue was solved. But I needed grouping. The author said

VirtualizingPanel.IsVirtualizingWhenGrouping

is added to .NET 4.5. So I set it to true. Now rendering is quick with grouping. The problem is... scrolling is jerky. Not unacceptably jerky, but noticeably jerky. I had similar problem when I tried to create a TreeView with 2000+ nodes expanded. Without virtualisation, rendering was slow but scrolling was smooth. With virtualisation, rendering was quick but scrolling was jerky.

Why can't we have both...

回答4:

In my case I had a problem with DataGridCell ControlTemplate that slowed rendering way down.

Be aware that relative loading speeds for large dataset are very different for using TextBlock (that is not selectable text) or TextBox in ReadOnly mode:

Loading time 59 seconds:

<Style TargetType="{x:Type DataGridCell}" x:Key="DataGridCellTextStyle">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type DataGridCell}">
                    <TextBox IsReadOnly="True" Text="{Binding Mode=OneWay}"/> 
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Loading time 21 seconds:

<Style TargetType="{x:Type DataGridCell}" x:Key="DataGridCellTextStyle">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type DataGridCell}">
                     <ContentPresenter Content="{Binding}" />
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Loading time 16 seconds:

<Style TargetType="{x:Type DataGridCell}" x:Key="DataGridCellTextStyle">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type DataGridCell}">
                    <TextBlock Text="{Binding}"></TextBlock>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

回答5:

Well a little bit adding more (i know its very old topic, but still it helps someone)...

I tried

EnableColumnVirtualization="True" VirtualizingPanel.VirtualizationMode="Recycling"
EnableRowVirtualization="True" 

for DataGrid(AutoGenerateColumns="True") binding to DataTable.DefaultView() and No effect on speed, it was still horrible for Speed as well as for navigation between rows. Than, I came up with solution to set Fixed Height and Width of DataGrid. Additionally I also set

RowHeight="23" 
ScrollViewer.HorizontalScrollBarVisibility="Visible"
ScrollViewer.VerticalScrollBarVisibility="Visible"

This makes my page fill very fast... Instead of 2 min, now it takes hardly 10-12 seconds.

Hope it helps someone.

Note: I am using .Net 4.5

回答6:

I have a Surface Pro 3 on which my datagrid, with about 200 rows and 10 columns, was really slow at scrolling, jerky and hesitant.

I thought it was the network, but it was in fact the graphics card not being able to keep up with - wait for it - a drop shadow effect on the datagrid itself, even though the background of the control was set to a solid colour.

I commented out the effect and it was 4-5 times faster.

Hope this helps.

回答7:

I have same problem with bound Data grid, and I notice that in first load it is fast but on secand and next it is slow. So when I add in code

DataGrid.ItemsSource = Nothing and then TableAdapter.Fill(Mydataset.MyStoredProcedure,....) DataGrid.ItemsSource=Mydataset.MyStoredProcedure it became very FAST

回答8:

For me it was:

<Setter Property='ScrollViewer.CanContentScroll' Value='False' />

I removed this from the style and the rendering became fast.

回答9:

I was having big issues with 1000 rows, 5 columns where the render time was taking 7-10 seconds, but the solution found at https://www.elegant-software.net/2014/05/performance-of-the-wpf-datagrid.html made the grid load instantly!

<DataGrid
   EnableRowVirtualization="True"
   EnableColumnVirtualization="True">