C# 如何将选定的组合框项目保存到.txt文件中

大家好，我是编程新手，我正在尝试使用WPF创建一个C#grade计算器，让用户输入他们的成绩，并删除其中两个最低的成绩，然后告诉他们他们的总体成绩，我已经让该部分工作，但我想它保存到一个txt文件从组合框中选择的成绩，也许能够加载到成绩计算器再次txt文件

这是我到目前为止的代码

<Window x:Class="GradeCalculator.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Grade Calculator" Height="779.736" Width="952">
<Grid>
    <Grid.Background>
        <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
            <GradientStop Color="White" Offset="1"/>
            <GradientStop Color="#FFAEF7F7"/>
            <GradientStop Color="#FFD0FAFA" Offset="0.49"/>
        </LinearGradientBrush>
    </Grid.Background>
    <Menu VerticalAlignment="Top" IsMainMenu="True" Margin="0,0,868,0"/>
    <Label Name="Title" Content="Grade Calculator" Margin="366,181,366,0" VerticalAlignment="Top" FontSize="25" HorizontalAlignment="Center" FontWeight="Bold" Width="212"/>
    <TextBlock Name="Information" HorizontalAlignment="Center" Margin="324,223,324,0" TextWrapping="Wrap" Text="Please enter your grades or predicted grades into the drop down menus below" VerticalAlignment="Top" Width="296" FontSize="16" TextAlignment="Center"/>
    <Label Name="Mandatory" Content="Mandatory Units" HorizontalAlignment="Left" Margin="156,273,0,0" VerticalAlignment="Top" Height="28" Width="122" FontSize="14" FontWeight="Bold"/>
    <TextBlock Name="CES" HorizontalAlignment="Left" Margin="12,306,0,0" TextWrapping="Wrap" VerticalAlignment="Top" FontSize="16"><Run Text="Communication and Employability"/><LineBreak/><Run Text="Skills for IT"/></TextBlock>
    <TextBlock Name="CS" HorizontalAlignment="Left" Margin="12,354,0,0" TextWrapping="Wrap" Text="Computer Systems" VerticalAlignment="Top" FontSize="16"/>
    <TextBlock Name="IS" HorizontalAlignment="Left" Margin="12,380,0,0" TextWrapping="Wrap" Text="Information Systems" VerticalAlignment="Top" FontSize="16"/>
    <TextBlock Name="SDD" HorizontalAlignment="Left" Margin="12,406,0,0" TextWrapping="Wrap" Text="Software Design and Development" VerticalAlignment="Top" FontSize="16"/>
    <TextBlock Name="SAD" HorizontalAlignment="Left" Margin="12,432,0,0" TextWrapping="Wrap" Text="Systems Analysis and Design" VerticalAlignment="Top" FontSize="16"/>
    <TextBlock Name="EDP" HorizontalAlignment="Left" Margin="10,462,0,0" TextWrapping="Wrap" Text="Event Driven Programming" VerticalAlignment="Top" FontSize="16"/>
    <ComboBox Name="CESBox" HorizontalAlignment="Left" Margin="288,318,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="CSBox" HorizontalAlignment="Left" Margin="288,354,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="ISBox" HorizontalAlignment="Left" Margin="288,462,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="SDDBox" HorizontalAlignment="Left" Margin="288,381,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="SADBox" HorizontalAlignment="Left" Margin="288,408,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="EDPBox" HorizontalAlignment="Left" Margin="288,435,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <Label Name="Optional" Content="Optional Units" HorizontalAlignment="Left" Margin="644,273,0,0" VerticalAlignment="Top" Height="28" Width="118" FontSize="14" FontWeight="Bold"/>
    <TextBlock Name="MN" HorizontalAlignment="Left" Margin="480,301,0,0" TextWrapping="Wrap" VerticalAlignment="Top" FontSize="16"><Run Text="Managing Network"/><Run Text="s"/></TextBlock>
    <TextBlock Name="CN" HorizontalAlignment="Left" Margin="480,327,0,0" TextWrapping="Wrap" Text="Computer Networks" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="CT" HorizontalAlignment="Left" Margin="480,354,0,0" TextWrapping="Wrap" Text="Communication Technologies" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="ITTS" HorizontalAlignment="Left" Margin="480,381,0,0" TextWrapping="Wrap" Text="IT Technical Support" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="ITTSTR" HorizontalAlignment="Left" Margin="480,408,0,0" TextWrapping="Wrap" Text="IT Systems and Troubleshooting and Repair" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="PPIT" HorizontalAlignment="Left" Margin="480,435,0,0" TextWrapping="Wrap" Text="Project Planning with IT" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="DB" HorizontalAlignment="Left" Margin="480,462,0,0" TextWrapping="Wrap" Text="Database Design" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="CSCWP" HorizontalAlignment="Left" Margin="480,489,0,0" TextWrapping="Wrap" Text="Client Side Customisation of Web Pages" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="DCG" HorizontalAlignment="Left" Margin="480,516,0,0" TextWrapping="Wrap" Text="Developing Computer Games" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="WSS" HorizontalAlignment="Left" Margin="480,543,0,0" TextWrapping="Wrap" Text="Web Server Scripting" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="WP" HorizontalAlignment="Left" Margin="480,570,0,0" TextWrapping="Wrap" Text="Website Production" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="DG" HorizontalAlignment="Left" Margin="480,597,0,0" TextWrapping="Wrap" Text="Digital Graphics" VerticalAlignment="Top" FontSize="16" Height="22"/>
    <TextBlock Name="NSS" HorizontalAlignment="Left" Margin="480,624,0,0" TextWrapping="Wrap" VerticalAlignment="Top" FontSize="16" Height="22"><Run Text="Network Systems Secur"/><Run Text="i"/><Run Text="ty"/></TextBlock>
    <TextBlock Name="WAIM" HorizontalAlignment="Left" Margin="480,651,0,0" TextWrapping="Wrap" VerticalAlignment="Top" FontSize="16" Height="22"><Run Text="Web Animation for Interactive Med"/><Run Text="i"/><Run Text="a"/></TextBlock>
    <ComboBox Name="MNBox" HorizontalAlignment="Left" Margin="798,300,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="CNBox" HorizontalAlignment="Left" Margin="798,327,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="CTBox" HorizontalAlignment="Left" Margin="798,354,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="ITTSBox" HorizontalAlignment="Left" Margin="798,381,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="ITTSTRBox" HorizontalAlignment="Left" Margin="798,408,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="PPITBox" HorizontalAlignment="Left" Margin="798,435,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="DBBox" HorizontalAlignment="Left" Margin="798,462,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="CSCWPBox" HorizontalAlignment="Left" Margin="798,489,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="DCGBox" HorizontalAlignment="Left" Margin="798,516,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="WSSBox" HorizontalAlignment="Left" Margin="798,543,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="WPBox" HorizontalAlignment="Left" Margin="798,570,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="DGBox" HorizontalAlignment="Left" Margin="798,597,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="NSSBox" HorizontalAlignment="Left" Margin="798,624,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <ComboBox Name="WAIMBox" HorizontalAlignment="Left" Margin="798,651,0,0" VerticalAlignment="Top" Width="120">
        <ComboBoxItem Content="Fail" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Pass" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Merit" HorizontalAlignment="Left" Width="118"/>
        <ComboBoxItem Content="Distinction" HorizontalAlignment="Left" Width="118"/>
    </ComboBox>
    <Button Name="SubButton" Content="Submit" HorizontalAlignment="Left" Margin="396,686,0,0" VerticalAlignment="Top" Click="Button_Click" Width="130" Height="38" FontSize="18"/>
    <Image Margin="324,0,298,541" Source="BSDC.png" Stretch="Fill"/>
    <Label Name="TotalGrade" Content="" HorizontalAlignment="Left" Margin="104,597,0,0" VerticalAlignment="Top" Height="49" Width="225" FontSize="30"/>
    <Label Name="TotalScore" Content="" HorizontalAlignment="Left" Margin="104,534,0,0" VerticalAlignment="Top" Height="49" Width="225" FontSize="30"/>
    <Button Name="SaveButton" Content="Save Grades" HorizontalAlignment="Left" Margin="12,10,0,0" VerticalAlignment="Top" Click="SaveButt_Click" Width="75"/>
</Grid>

public主窗口（）
{
初始化组件（）；
}
私有无效按钮\u单击（对象发送者，路由目标e）
{
int-total=0；
总计+=GetGrade（CESBox）；
总计+=GetGrade（CSBox）；
总计+=GetGrade（ISBox）；
总计+=GetGrade（SDDBox）；
总计+=GetGrade（SADBox）；
总计+=GetGrade（EDPBox）；
总计+=GetGrade（MNBox）；
总计+=GetGrade（CNBox）；
总计+=GetGrade（CTBox）；
总计+=GetGrade（ITTSBox）；
总计+=GetGrade（ITTSTRBox）；
总计+=GetGrade（PPITBox）；
总计+=GetGrade（数据库框）；
总计+=GetGrade（CSCWPBox）；
总计+=GetGrade（DCGBox）；
总计+=GetGrade（WSSBox）；
总计+=GetGrade（WPBox）；
总计+=GetGrade（DGBox）；
总计+=GetGrade（NSSBox）；
总计+=GetGrade（WAIMBox）；
总数-=低等级1；
总数-=低等级2；
如果（总计>=1300&&total=1340&&total=1380&&total=1420&&total=1460&&total=1500&&total=1530&&total=1560&&total=1590）
{
grade=“D*D*D*”；
}
TotalScore.Content=“Score=”+总计；
TotalGrade.Content=“Grade=“+等级；
}
public int GetGrade（组合框cbContent）
{
智力得分=0；
ComboBoxItem cbContentSelectedItem=cbContent.SelectedItem作为ComboxItem；
如果（cbContentSelectedItem！=null）
{
如果（（字符串）cbContentSelectedItem.Content==“Fail”）
{
如果（低等级1>0）
{
低等级1=0；
}
否则如果（低等级2>0）
{
低等级2=0；
}
得分=0；
}
如果（（字符串）cbContentSelectedItem.Content==“Pass”）
{
如果（低等级1>70）
{
低等级1=70；
}
否则，如果（低等级2>70）
{
低等级2=70；
}
得分=70分；
}
如果（（字符串）cbContentSelectedItem.Content==“优点”）
{
如果（低等级1>80）
{
低等级1=80；
}
否则，如果（低等级2>80）
{
低等级2=80；
}
得分=80分；
}
如果（（字符串）cbContentSelectedItem.Content==“区分”）
{
如果（低等级1>90）
{
低等级1=90；
}
否则，如果（低等级2>90）
{
低等级2=90；
}
得分=90分；
}
}
返回分数；
}
私有void SaveButt\u单击（对象发送方，路由目标）
{
}
}

---

}

如果您在访问C:\时遇到问题，则您的应用程序存在权限问题

尝试创建一个新文件夹“C:\Test”，并尝试在那里写入。或者以管理员身份启动visual studio。还包括文件名

public partial class MainWindow : Window 
{ 
    public MainWindow() 
    { 
          InitializeComponent(); 
    } 
    private void SaveButt_Click(object sender, RoutedEventArgs e) 
    {           
          File.WriteAllText("C:\\file.txt", "Hello World!"); 
    } 
}

---

另请检查此项以了解更多信息

您可以使用File.writealText（）或Streamwriter写入文本文件。您尝试过什么？你读过MSDN上的组合框吗？关于写入文件，你知道些什么？我尝试过其他人的代码，也尝试过将其放入我的代码中，但我似乎无法让它按我所希望的方式工作，这些东西包括file.writell和Streamwriter，但我无法让它们都工作，我对写入文件知之甚少，因为我刚开始编程时就有了这样的东西：private void SaveButt\u Click（object sender，RoutedEventArgs e）{string path=“C:\\”string selectedValue=CESBox.SelectedItem.ToString（）；file.writealText（path，selectedValue）；}但我得到了这个错误：mscorlib.dll中发生了类型为“System.UnauthorizedAccessException”的未经处理的异常。其他信息：对路径“C:\”的访问被拒绝。这些建议都没有起作用，程序仍然在同一点崩溃。@user3037305然后简化您的问题。删除所有代码，只包含您正在尝试的写文件的代码。比如将文本“Hello World”保存到文件中。先试试基本的。获取一个简单的编写示例

public partial class MainWindow : Window 
{ 
    public MainWindow() 
    { 
          InitializeComponent(); 
    } 
    private void SaveButt_Click(object sender, RoutedEventArgs e) 
    {           
          File.WriteAllText("C:\\file.txt", "Hello World!"); 
    } 
}