wpf中，当DataGrid.ItemsSource与ObservableCollection绑定后，值变化时，DataGrid如何刷新？

Posted 2023-05-06

private ObservableCollection<ZDMsgFile> _zdmsgFile = new ObservableCollection<ZDMsgFile>();

DataGrid.ItemsSource = _zdmsgFile；
当在后台_zdmsgFile值变化时，DataGrid显示的内容并不变化，
在_zdmsgFile变化后，调用DataGrid的什么方法能使DataGrid的显示的数据与_zdmsgFile同步？
谢谢

参考技术A 先设置DataGrid的ItemsSource 为空，然后重新绑定：

this.DataGrid.ItemsSource = null;
this.DataGrid.ItemsSource = _zdmsgFile;本回答被提问者采纳

当列表视图中的扩展器折叠时，无法让 WPF 列表视图折叠

【中文标题】当列表视图中的扩展器折叠时，无法让 WPF 列表视图折叠

【英文标题】：Can't get WPF Listview to collapse when expanders in the listview collapse

【发布时间】：2010-11-25 18:20:21

【问题描述】：

我有一个 wpf ListView，里面有两个 Expanders。当扩展器展开列表视图时，会为内容腾出空间。当它们折叠时，列表视图不会“收回”额外的空间。我已将HorizontalAlignment 和VerticalAlignment 设置为Stretch。有没有办法做到这一点？ Details 和 Chart 列包含扩展器。请参阅下面的代码。谢谢。

这里

<Window.Resources>

    <DataTemplate x:Key="StockPriceChangeCell">
        <StackPanel Orientation="Horizontal">
            <Label Name="stockPriceChangeValue" Foreground="Binding StockPriceChangeColor" Content="Binding StockPriceChange" Width="Auto"></Label>
        </StackPanel>
    </DataTemplate>

    <DataTemplate x:Key="DetailsCell">
        <StackPanel Orientation="Horizontal" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
            <Expander Header="Details..." BorderBrush="DarkBlue" Width="200" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                <Grid Name="stockDetailGrid" Background="Beige" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" ShowGridLines="False">
                    <Grid.RowDefinitions>
                        <RowDefinition Height="96*" />
                        <RowDefinition Height="6*" />
                        <RowDefinition Height="96*" />
                        <RowDefinition Height="6*" />
                        <RowDefinition Height="96*" />
                        <RowDefinition Height="6*" />
                        <RowDefinition Height="96*" />
                        <RowDefinition Height="6*" />
                        <RowDefinition Height="96*" />
                        <RowDefinition Height="96*" />
                        <RowDefinition Height="96*" />
                        <RowDefinition Height="6*" />
                        <RowDefinition Height="96*" />
                        <RowDefinition Height="6*" />
                        <RowDefinition Height="96*" />
                        <RowDefinition Height="6*" />
                        <RowDefinition Height="96*" />
                        <RowDefinition Height="6*" />
                        <RowDefinition Height="96*" />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto" />
                        <ColumnDefinition Width="Auto" />
                    </Grid.ColumnDefinitions>
                    <Label Grid.Row="0" Grid.Column="0" Name="previousClosePrompt" FontWeight="Bold" FontSize="12" Height="28" Width="Auto">Prev Close:</Label>
                    <Label Grid.Row="0" Grid.Column="1" Name="previousCloseValue" FontWeight="Bold" FontSize="12" Height="28" Width="Auto" Content="Binding StockDetails.PreviousClose"></Label>
                    <Separator Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2" Name="stockSeparator3" Margin="0,2" />
                    <Label Grid.Row="2" Grid.Column="0" Name="openPricePrompt" FontWeight="Bold" FontSize="12" Height="28">Open:</Label>
                    <Label Grid.Row="2" Grid.Column="1" Name="openPriceValue" FontWeight="Bold" FontSize="12" Height="28" Content="Binding StockDetails.OpeningPrice"></Label>
                    <Separator Grid.Row="3" Grid.Column="0" Grid.ColumnSpan="2" Name="stockSeparator5" Margin="0,2" />
                    <Label Grid.Row="4" Grid.Column="0" Name="yearlyTargetEstimatePrompt" FontWeight="Bold" FontSize="12" Height="28">1y Target Est:</Label>
                    <Label Grid.Row="4" Grid.Column="1" Name="yearlyTargetEstimateValue" FontWeight="Bold" FontSize="12" Height="28" Content="Binding StockDetails.YearTargetEstimate"></Label>
                    <Separator Grid.Row="5" Grid.Column="0" Grid.ColumnSpan="2" Name="stockSeparator6" Margin="0,2" />
                    <Label Grid.Row="6" Grid.Column="0" Name="stockDaysRangePrompt" FontWeight="Bold" FontSize="12" Height="28">Day's Range:</Label>
                    <Label Grid.Row="6" Grid.Column="1" Name="stockDaysRangeValue" FontWeight="Bold" FontSize="12" Height="28" Content="Binding StockDetails.DaysRange"></Label>
                    <Separator Grid.Row="7" Grid.Column="0" Grid.ColumnSpan="2" Name="stockSeparator7" Margin="0,2" />
                    <Label Grid.Row="8" Grid.Column="0" Name="stockYearsRangePrompt" FontWeight="Bold" FontSize="12" Height="28">52wk Range:</Label>
                    <Label Grid.Row="8" Grid.Column="1" Name="stockYearsRangeValue" FontWeight="Bold" FontSize="12" Height="28" Content="Binding StockDetails.YearsRange"></Label>
                    <Separator Grid.Row="9" Grid.Column="0" Grid.ColumnSpan="2" Name="stockSeparator8" Margin="0,2" />

                    <Label Grid.Row="10" Grid.Column="0" Name="averageVolumePrompt" FontWeight="Bold" FontSize="12" Height="28">Avg Vol (3m):</Label>
                    <Label Grid.Row="10" Grid.Column="1" Name="averageVolumeValue" FontWeight="Bold" FontSize="12" Height="28" Content="Binding StockDetails.AverageVolume"></Label>
                    <Separator Grid.Row="11" Grid.Column="0" Grid.ColumnSpan="2" Name="stockSeparator9" Margin="0,2" />
                    <Label Grid.Row="12" Grid.Column="0" Name="marketCapPrompt" FontWeight="Bold" FontSize="12" Height="28">Market Cap:</Label>
                    <Label Grid.Row="12" Grid.Column="1" Name="marketCapValue" FontWeight="Bold" FontSize="12" Height="28" Content="Binding StockDetails.MarketCap"></Label>
                    <Separator Grid.Row="13" Grid.Column="0" Grid.ColumnSpan="2" Name="stockSeparator10" Margin="0,2" />
                    <Label Grid.Row="14" Grid.Column="0" Name="priceEarningRatioPrompt" FontWeight="Bold" FontSize="12" Height="28">P/E (ttm):</Label>
                    <Label Grid.Row="14" Grid.Column="1" Name="priceEarningRatioValue" FontWeight="Bold" FontSize="12" Height="28" Content="Binding StockDetails.PriceEarningsRatio"></Label>
                    <Separator Grid.Row="15" Grid.Column="0" Grid.ColumnSpan="2" Name="stockSeparator11" Margin="0,2" />
                    <Label Grid.Row="16" Grid.Column="0" Name="earningsPerSharePrompt" FontWeight="Bold" FontSize="12" Height="28">EPS (ttm):</Label>
                    <Label Grid.Row="16" Grid.Column="1" Name="earningsPerShareValue" FontWeight="Bold" FontSize="12" Height="28" Content="Binding StockDetails.EarningsPerShare"></Label>
                    <Separator Grid.Row="17" Grid.Column="0" Grid.ColumnSpan="2" Name="stockSeparator12" Margin="0,2" />
                    <Label Grid.Row="18" Grid.Column="0" Name="dividendYieldPrompt" FontWeight="Bold" FontSize="12" Height="28">Div &amp; Yield:</Label>
                    <Label Grid.Row="18" Grid.Column="1" Name="dividendYieldValue" FontWeight="Bold" FontSize="12" Height="28" Content="Binding StockDetails.DividendYield"></Label>
                </Grid>
            </Expander>
        </StackPanel>
    </DataTemplate>

    <DataTemplate x:Key="ChartCell">
        <StackPanel>
            <Expander Header="Chart..." BorderBrush="DarkBlue" Width="200" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                <Image Name="stockGraph" Stretch="None" Source="Binding StockChart"/>
            </Expander>
        </StackPanel>
    </DataTemplate>
</Window.Resources>

这是列表视图：

                <TabItem Name="myStocksTab" Header="My Stocks" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                    <StackPanel Name="myStocksTabContainerPanel" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                        <Label Name="myStocksPrompt" Foreground="GhostWhite" Background="DarkBlue" FontSize="16" FontWeight="Bold">My Stocks</Label>
                            <ListView Name="stocksUIList" ItemsSource="Binding" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" VerticalContentAlignment="Stretch">
                                <ListView.View>
                                    <GridView>
                                        <GridViewColumn Header="Action" CellTemplate="StaticResource ButtonsCell" Width="Auto"/>
                                        <GridViewColumn Header="Company/Stock Symbol" Width="Auto" DisplayMemberBinding="Binding CompanyName"/>
                                        <GridViewColumn Header="Last Trade" Width="Auto" DisplayMemberBinding="Binding LastTrade"/>
                                        <GridViewColumn Header="Trade Time" Width="Auto" DisplayMemberBinding="Binding StockDetails.TradeTime"/>
                                        <GridViewColumn Header="Change" CellTemplate="StaticResource StockPriceChangeCell"/>
                                        <GridViewColumn Header="Volume" Width="Auto" DisplayMemberBinding="Binding TradingVolume"/>
                                        <GridViewColumn Header="Details" CellTemplate="StaticResource DetailsCell" Width="215"/>
                                        <GridViewColumn Header="Chart" CellTemplate="StaticResource ChartCell" Width="215"/>
                                    </GridView>
                                </ListView.View>
                            </ListView>
                        <Button Name="addStock" FontSize="14" FontWeight="Bold" VerticalAlignment="Bottom" HorizontalAlignment="Stretch" Click="AddCompanyStock">Add Stock...</Button>
                    </StackPanel>

【参考方案1】：

我知道这是一篇较旧的帖子，但我一直在寻找解决此问题的方法，并希望用我的解决方案对其进行更新。

经过一番搜索，我能够使用此处找到的解决方案来修复它：ListView with nested Expander not collapsing

基本上，我在项目模板中使用了带有扩展器的 ListView。折叠扩展器时无法正确调整大小。此外，当扩展器内容大于 ListView 时，滚动将无法正常工作。

修复只是简单地将 ListView 替换为 ItemsControl 并将 ItemsControl 放入 ScrollViewer。

【参考方案2】：

听起来 ListView 中可能存在某种布局错误。您是否尝试过在任一扩展器的 Collapsed 事件中调用 ListView 上的 InvalidateVisual()？这可能会奏效。

【讨论】：

同样的问题，但 InvalidateVisual() 似乎没有效果。