我試圖讓用戶從我的數(shù)據(jù)庫中選擇要顯示的表，我聽說這樣做的最佳方法是使用“selectedIndexChanged”事件，這樣當用戶單擊所需的表時，它會立即顯示它。但是，出于某種原因，當我單擊我的組合框然后單擊事件時，我沒有看到“selectedIndexChanged”作為一個選項，并且在手動編寫時顯示：“無法識別成員“SelectedIndexChanged”或無法訪問“這是我的 xaml 代碼： <Window x:Class="WpfApp1.MainWindow"    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"    xmlns:local="clr-namespace:WpfApp1"    mc:Ignorable="d"    Title="MainWindow" Height="350" Width="525"><Grid>    <Grid.ColumnDefinitions>        <ColumnDefinition Width="4*"/>        <ColumnDefinition Width="*"/>    </Grid.ColumnDefinitions>    <Canvas Name="mycanvas" Background="LightBlue" Margin="0,0,34.4,-0.2">        <DataGrid Name="g1">        </DataGrid>        <Label Name="l1" Content="" FontWeight="ExtraBold" FontSize="15" Foreground="{x:Null}" Canvas.Left="20"/>    </Canvas>    <Canvas Grid.Column="1">        <Label Name="Instruction" Content="Choose a table" FontWeight="ExtraBold" FontSize="15" Canvas.Left="-23" Canvas.Top="62"/>        <ComboBox SelectedIndexChanged="b1" Name="ComboBox1" FontWeight="Bold" FontSize="15" Canvas.Top="98" Width="135" Height="24" Canvas.Left="-31">            <ComboBoxItem Foreground="#FF3FA4C5"  Name="classesTbl">classesTbl</ComboBoxItem>            <ComboBoxItem Foreground="#FF3FA4C5" Name="gradesTbl">gradesTbl</ComboBoxItem>            <ComboBoxItem Foreground="#FF3FA4C5" Name="studentsTbl">studentsTbl</ComboBoxItem>            <ComboBoxItem Foreground="#FF3FA4C5" Name="subjectsTbl">subjectsTbl</ComboBoxItem>            <ComboBoxItem Foreground="#FF3FA4C5" Name="subjectsTeachers">subjectsTeachers</ComboBoxItem>            <ComboBoxItem Foreground="#FF3FA4C5" Name="TeachersTbl">TeachersTbl</ComboBoxItem>        </ComboBox>    </Canvas></Grid>有誰知道如何解決它或我做錯了什么？