今天在使用DataGrid的下拉列表列时因设置SelectedValueBinding="{Binding 触发沿, Mode=OneWay}"，导致下拉列表一直无法显示，查找半天最后发现将Mode改成TwoWay，问题解决。
<DataGrid VerticalAlignment="Stretch" x:Name="dgItems" Height="Auto" SelectionUnit="FullRow" SelectionMode="Extended" CanUserAddRows="False" DataContext="{Binding}" Width="Auto" AutoGenerateColumns="False" FontSize="16" AlternatingRowBackground="LightBlue" AlternationCount="2" Margin="10, 10" Background="Transparent" ScrollViewer.VerticalScrollBarVisibility="Visible"> <DataGrid.Resources> <col:ArrayList x:Key="key_triggerList"> <col:DictionaryEntry Key="上升沿" Value="上升沿"/> <col:DictionaryEntry Key="下降沿" Value="下降沿"/> </col:ArrayList> <col:ArrayList x:Key="key_attenuatorList"> <col:DictionaryEntry Key=" 0dB" Value="0"/> <col:DictionaryEntry Key="20dB" Value="20"/> <col:DictionaryEntry Key="40dB" Value="40"/> <col:DictionaryEntry Key="60dB" Value="60"/> </col:ArrayList> </DataGrid.Resources> <DataGrid.Columns> <DataGridTextColumn Header="IP" Width="120*" Binding="{Binding IP, Mode=OneWay}" /> <DataGridComboBoxColumn Header="触发沿" Width="80*" IsReadOnly="False" DisplayMemberPath="Key" SelectedValuePath="Value" SelectedValueBinding="{Binding 触发沿, Mode=TwoWay}" ItemsSource="{StaticResource key_triggerList}"/> <DataGridTextColumn Header="触发电平(V)" IsReadOnly="False" Width="80*" Binding="{Binding 触发电平, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" /> <DataGridComboBoxColumn Header="衰减器" IsReadOnly="False" Width="80*" DisplayMemberPath="Key" SelectedValuePath="Value" SelectedValueBinding="{Binding 衰减器, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" ItemsSource="{StaticResource key_attenuatorList}"/> </DataGrid.Columns></DataGrid>注意在xaml的<window/>节增加
<window xmlns:col="clr-namespace:System.Collections;assembly=mscorlib"></window>