为什么我得到这个错误窗口形式？

Question

System.InvalidCastException: Unable to cast object of type 'System.String' to type 'Cookie.Dozen'.  at Cookie.CookieSource.listBox1_SelectedIndexChanged(Object sender,  EventArgs e) in Form1.cs:line 112

第112行如下：

private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    this.dozen = (Dozen) this.listBox1.SelectedItem;
    this.CostChosenLb.ResetText();
}

我要做的是，当我从列表框中选择一个项目时，它将在文本框中显示价格。但每当我尝试这样做时，我都会遇到错误。救命啊！

Answer 1

您的ListBox绑定到字符串Type而不是Dobu类型。您应该检查如何设置ListBox Items属性。

this.listBox1.Items = yoursList

您可以尝试将代码更改为：

private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    this.dozen = this.listBox1.SelectedItem as Dozen;
    this.CostChosenLb.ResetText();
}