C# 将项目添加到画布内WPF中的combobox

你好

我想将特定项目添加到组合框中，但遇到错误

代码：

添加类型-AssemblyName PresentationFramework
[xml]$Form=@”
"@
$NR=（新对象System.Xml.XmlNodeReader$Form）
$Win=[Windows.Markup.XamlReader]：：加载（$NR）
$Win.Showdialog（）

如您所见，我尝试添加项，但错误如下

Cannot convert value "<Window xmlns=...</Window>" to type "System.Xml.XmlDocument".
Error: "The 'Canvas' start tag on line 4 position 6 does not match the end tag of 
'ComboBox'. Line 12, position 11."
At H:\Scripts\Form_Main_XAML.ps1:3 char:1
+ [xml]$Form = @"
+ ~~~~~~~~~~~~~~~
    + CategoryInfo          : MetadataError: (:) [], ArgumentTransformationMetadataException
    + FullyQualifiedErrorId : RuntimeException

无法转换表示以下内容的块的值“：

<ComboBox Name="ComboBox_Location" HorizontalAlignment="Left" Margin="170,56,0,0" VerticalAlignment="Top" Width="160"/>
    <ComboBoxItem Content="X"/>
    <ComboBoxItem Content="Y"/>
    <ComboBoxItem Content="Z"/>
</ComboBox>  



第一行以
/>
结尾，在该行中，结束标记指定组合框定义的结尾。相反，您希望以
结尾，并让相应的
行关闭块。
您的XAML组合框有一个结束标记，但它不应该：

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    Title="Printer GUI" Height="465" Width="375">
    <Canvas Background="White">
        <Label Name="label_username" Content="Username" HorizontalAlignment="Left" Margin="30,30,0,0" VerticalAlignment="Top"/>
        <Label Name="label_Location" Content="Select Location" HorizontalAlignment="Left" Margin="170,30,0,0" VerticalAlignment="Top"/>
        <TextBox Name="textbox_username" HorizontalAlignment="Left" Height="23" Margin="30,56,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>
        <ComboBox Name="ComboBox_Location" HorizontalAlignment="Left" Margin="170,56,0,0" VerticalAlignment="Top" Width="160">
            <ComboBoxItem Content="X"/>
            <ComboBoxItem Content="Y"/>
            <ComboBoxItem Content="Z"/>
        </ComboBox>  
        <Label Name="label_printer" Content="Please select printer from list" HorizontalAlignment="Left" Margin="30,105,0,0" VerticalAlignment="Top"/>
        <ComboBox Name="ComboBox_Printer" HorizontalAlignment="Left" Margin="30,131,0,0" VerticalAlignment="Top" Width="300"/>
        <CheckBox Name="CheckBox" Content="Check here if you want to add this printer &#xA;&#x9;to your permanent list" HorizontalAlignment="Left" Margin="56,185,0,0" VerticalAlignment="Top" Height="39" Width="245"/>
        <Button Name="Button_Add" Content="Add Printer" Margin="140,244,140,150" Width="75" Height="25" VerticalAlignment="Center" ClickMode="Release"/>
        <Button Name="Button_XPS" Content="Printer Defaults issue&#xD;&#xA;  in Practice Partner" Margin="90,285,90,102" Width="175" Height="40" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" ClickMode="Release" VerticalAlignment="Center"/>
        <Button Name="Button_Service" Content="Service call for Printer" Margin="113,343,110,51" Width="130" Height="25" VerticalAlignment="Center" ClickMode="Release"/>
        <Button Name="Button_Cancel" Content="Cancel" Margin="140,384,140,10" Width="75" Height="25" VerticalAlignment="Center" ClickMode="Release"/>
    </Canvas>
</Window>


谢谢@Chris。我应该知道这是一个简单的修复。我需要观察我的开始和结束。谢谢你的解释！@Megamidget3一点问题都没有！这是我第一次在中学习XAML时的一个小烦恼，而不是本能地键入
/
来完成标记，因为它会自动填充
。我的建议n就是养成创建控件的习惯，
，这样它会自动为您填充
，并将其隔开，从而为您提供一个视觉提示，让您将子项放入其中。
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    Title="Printer GUI" Height="465" Width="375">
    <Canvas Background="White">
        <Label Name="label_username" Content="Username" HorizontalAlignment="Left" Margin="30,30,0,0" VerticalAlignment="Top"/>
        <Label Name="label_Location" Content="Select Location" HorizontalAlignment="Left" Margin="170,30,0,0" VerticalAlignment="Top"/>
        <TextBox Name="textbox_username" HorizontalAlignment="Left" Height="23" Margin="30,56,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>
        <ComboBox Name="ComboBox_Location" HorizontalAlignment="Left" Margin="170,56,0,0" VerticalAlignment="Top" Width="160">
            <ComboBoxItem Content="X"/>
            <ComboBoxItem Content="Y"/>
            <ComboBoxItem Content="Z"/>
        </ComboBox>  
        <Label Name="label_printer" Content="Please select printer from list" HorizontalAlignment="Left" Margin="30,105,0,0" VerticalAlignment="Top"/>
        <ComboBox Name="ComboBox_Printer" HorizontalAlignment="Left" Margin="30,131,0,0" VerticalAlignment="Top" Width="300"/>
        <CheckBox Name="CheckBox" Content="Check here if you want to add this printer &#xA;&#x9;to your permanent list" HorizontalAlignment="Left" Margin="56,185,0,0" VerticalAlignment="Top" Height="39" Width="245"/>
        <Button Name="Button_Add" Content="Add Printer" Margin="140,244,140,150" Width="75" Height="25" VerticalAlignment="Center" ClickMode="Release"/>
        <Button Name="Button_XPS" Content="Printer Defaults issue&#xD;&#xA;  in Practice Partner" Margin="90,285,90,102" Width="175" Height="40" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" ClickMode="Release" VerticalAlignment="Center"/>
        <Button Name="Button_Service" Content="Service call for Printer" Margin="113,343,110,51" Width="130" Height="25" VerticalAlignment="Center" ClickMode="Release"/>
        <Button Name="Button_Cancel" Content="Cancel" Margin="140,384,140,10" Width="75" Height="25" VerticalAlignment="Center" ClickMode="Release"/>
    </Canvas>
</Window>