C#-TargetInvocationException发生,但我绝对不知道为什么

An unhandled exception of type ‘System.Reflection.TargetInvocationException’ occurred in PresentationFramework.dll.

Additional information: Exception has been thrown by the target of an invocation.

简而言之,这是我的代码.它是两个文本框的计算器,当用户按下WPF中的-,/,x按钮时,它们应该一起成为一个新的答案.

public partial class MainWindow : Window
{
    public string numberInString
    {
        get { return TextDoos.Text; }
        set { TextDoos.Text = value; }
    }

    public MainWindow()
    {
        if(TextDoos.Text == "")
        {
            if(TextDoos2.Text == "")
            {
                RekenFunctie(TextDoos.Text, TextDoos2.Text);
            }
        }
    }
}

public int RekenFunctie(string numberInString, string numberInString)
{
    int antwoord;
    int getal = Convert.ToInt32(numberInString);
    int getal2 = Convert.ToInt32(numberInString2);

    if (Buttons.IsPressed) // This is the + button, there are also -,x,/ buttons.
    {
       antwoord = getal + getal2;
       return antwoord;
    }
}

我不明白为什么它不起作用…

public MainWindow() 
{ 
     InitializeComponent();
     button1.Click += button1_click; //'+' button
}

private void button1_click(object sender, RoutedEventArgs e)
{
    int antwoord;
    int getal = Convert.ToInt32(TextDoos.Text);
    int getal2 = Convert.ToInt32(TextDoos2.Text);

    antwoord = getal + getal2;
    resultTextBox.Text = antwoord ;
}

无论如何,您的代码很奇怪. RekenFunctie进行了一些计算,但是您可以从构造函数中调用它.因此,您只运行一次此代码,但是我认为您的用户希望与您的计算器进行交互.

我认为您应该阅读有关Button.Click事件的信息.