我需要加入字符串和List<string>项。我的代码
List<string> list = new List<string>() { "item1", "item2" };
string item3 = "item3";
string result = string.Join(",", list, item3);
结果是
//System.Collections.Generic.List`1[System.String],item3
而非预期
//item1,item2,item3
最优雅的方法是什么，以解决这个内联？可能有多个List<string>和多个string，每个<Grid >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="5*"/>
<ColumnDefinition Width="1*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="1*"/>
<RowDefinition Height="7*"/>
</Grid.RowDefinitions>
<StackPanel Orientation="Horizontal">
<CheckBox x:Name="cbMoveResize" Content="Move and resize" Grid.Row="0"/>
<CheckBox x:Name="cbDrawRectangle" Content="Draw rectangle" Grid.Row="0"/>
</StackPanel>
<ScrollViewer Grid.Column="0" Grid.Row="1" ScrollViewer.HorizontalScrollBarVisibility="Auto">
<Grid x:Name="mainGrid" Grid.Column="0" Background="Gray" Width="Auto" Height="Auto" MouseMove="Image_MouseMove" MouseDown="Image_MouseDown" MouseUp="Image_MouseUp" MouseLeave="leaveGrid" MouseWheel="UIElement_OnMouseWheel">
<Image x:Name="bmpImage" HorizontalAlignment="Left" VerticalAlignment="Top" />
<Canvas IsHitTestVisible="True" x:Name="imageCanvas" Width="{Binding Width, ElementName=bmpImage}" Height="{Binding Height, ElementName=bmpImage}">
<ItemsControl ItemsSource="{Binding rectTest, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type local:MainWindow}}}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Canvas IsItemsHost="True"/>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemContainerStyle>
<Style TargetType="ContentPresenter">
<Setter Property="Canvas.Left" Value="{Binding Path = r.X}"/>
<Setter Property="Canvas.Top" Value="{Binding Path = r.Y}"/>
</Style>
</ItemsControl.ItemContainerStyle>
<ItemsControl.ItemTemplate>
<DataTemplate>
<ContentControl Height="{Binding r.Height, Mode=TwoWay}" Width="{Binding r.Width, Mode=TwoWay}" x:Name="nume">
<ContentControl.Style>
<Style TargetType="ContentControl">
<Setter Property="Template" Value="{StaticResource defaultTemplate}"/>
<Style.Triggers>
<DataTrigger Binding="{Binding ElementName=cbMoveResize, Path=IsChecked}" Value="True">
<Setter Property="Template" Value="{StaticResource moveAndResizeTemplate}"/>
</DataTrigger>
</Style.Triggers>
</Style>
</ContentControl.Style>
<Rectangle Stroke="Red" StrokeThickness="2" Height="{Binding r.Height, Mode=TwoWay}" Width="{Binding r.Width, Mode=TwoWay}"/>
</ContentControl>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Canvas>
</Grid>
</ScrollViewer>
<Grid Name="smallGrid" Grid.Column="2" Grid.Row="2">
<Grid.RowDefinitions>
<RowDefinition Height="1*"/>
<RowDefinition Height="8*"/>
</Grid.RowDefinitions>
<Button Name="btnLoad" Margin="2" Height="25" Content="Load" VerticalAlignment="Top" Click="btnLoad_Click"/>
<Canvas x:Name="grid2" Grid.Row="1" Width="{Binding Width, ElementName=smallGrid}" Height="Auto">
<Image x:Name="cropIm" Width="{Binding ActualWidth, ElementName=grid2, Mode=OneWay}" Height="{Binding ActualHeight, ElementName=grid2, Mode=OneWay}" />
</Canvas>
</Grid>
</Grid>
都可以为空。
答案 0 :(得分：7)
您可以使用Concat连接所有字符串（不更改原始列表！）和可枚举的Join：
List<string> list = new List<string>() { "item1", "item2" };
string item3 = "item3";
string result = string.Join(",", list.Concat(new string[] { item3 }));
// result = item1,item2,item3
您当前代码的问题在于它调用string.Join(string, params IEnumerable<object>)：它会将list视为对象，而不是对象的lis。
答案 1 :(得分：1)
如果最终结果需要是单个string，那么您可以使用类似的内容。这将首先将list加入单string，然后将其加入item3：
string result = string.Join (",", string.Join (",", list), item3);
对于每个额外的List，您可以添加其他string.Join (",", otherList)子句。
答案 2 :(得分：0)
那怎么样？
string result = string.Join(",", list.Concat(new string[1] { item3 }));