问题
In WPF, I have a DataGrid
bound to a DataView
in the ViewModel
class. It is a touch panel embedded project, so every time I touch and slide my fingers on the panel it keeps sending me values and saves those values to the DataTable
and assigns it to the bound DataView
in a way where it can show only 5 or 10 rows (predefined) as the data gets updated. Every time I get a new row I delete the last until the total DataTable
row count is 5/10.
The issue here is that it is taking longer than usual for the DataGrid
to bind to the last values. The moment I lift my hand off the panel, I expect the grid to bind to those values, but it is taking some 6 to 10 seconds to do this operation where the user has to wait for it to complete.
For this, I have used the IsAsync
property in XAML
. As expected, this makes the DataGrid
bind fast but every time the data gets updated, the DataGrid
flickers. How can I overcome the flickering issue in the DataGrid
? Or is there any other way to do it. We are following MVVM patterns for the binding.
XAML:
<DataGrid
ItemsSource="{Binding Path=View, IsAsync=True, UpdateSourceTrigger=PropertyChanged}"
CanUserSortColumns="False"
CanUserResizeRows="False"
HorizontalScrollBarVisibility="Hidden"
VerticalScrollBarVisibility="Hidden"
EnableColumnVirtualization="True"
EnableRowVirtualization="True"
CanUserAddRows="False">
</DataGrid>
View Model:
private void InsertCollection(List<string> values)
{
if (values == null || !values.Any()) return;
try
{
var dataRow = ObjectMessageDataTable.NewRow();
int columnCount = ObjectMessageDataTable.Columns.Count;
var inputs = values.Select(y => y as object).ToArray();
for (var i = 0; i < inputs.Count() && i < columnCount; i++)
dataRow[i] = values[i];
ObjectMessageDataTable.Rows.InsertAt(dataRow, 0);
var count = ObjectMessageDataTable.Rows.Count;
while (count > NumOfRows)
{
ObjectMessageDataTable.Rows.RemoveAt(NumOfRows);
count = ObjectMessageDataTable.Rows.Count;
}
ObjectMessageDataTable.AcceptChanges();
View = ObjectMessageDataTable.DefaultView;
}
catch (Exception ex)
{
}
}
回答1:
I tried your code. It is so simple to databind the datatable directly and the flickering will go away :). just use ObjectMessageDataTable.DefaultView instead of View. Because somehow the View object itself is created everytime View is created and this causes the datagrid to initialise from the beginning.
ItemsSource="{Binding Path=ObjectMessageDataTable.DefaultView, IsAsync=True, UpdateSourceTrigger=PropertyChanged}"
so change to
<DataGrid
Grid.Row="1"
Width="Auto"
Height="Auto"
Margin="0,20,0,0"
HorizontalAlignment="Center"
VerticalAlignment="Top"
HorizontalContentAlignment="Center"
VerticalContentAlignment="Center"
AlternatingRowBackground="WhiteSmoke"
AlternationCount="2"
AutoGenerateColumns="True"
BorderBrush="Black"
BorderThickness="1"
CanUserAddRows="False"
CanUserResizeRows="False"
CanUserSortColumns="False"
ColumnHeaderHeight="35"
EnableColumnVirtualization="True"
EnableRowVirtualization="True"
HorizontalScrollBarVisibility="Hidden"
ItemsSource="{Binding Path=ObjectMessageDataTable.DefaultView, IsAsync=True, UpdateSourceTrigger=PropertyChanged}"
RowHeight="30"
VerticalScrollBarVisibility="Hidden" />
Hope it helps.
来源:https://stackoverflow.com/questions/48971769/wpf-datagrid-flickering-issue