为什么if else语句起作用但本Switch语句不起作用

Question

我有这个if else语句，可以在ExamController.cs上很好地运行，但是我想使用switch语句使它更易于阅读。我添加到switch语句的唯一一件事就是ExamId。

如果else语句起作用但我的切换情况不起作用，这怎么会这样。错误与退货有关，但是我没有对退货进行任何更改。

if (model.SearchType == "School")
{
    result = FindExams((e) => e.School.School_Name.Contains(model.SearchInput));
}
else if (model.SearchType == "Exam Date")
{
    result = FindExams((e) => e.Exam.ExamDate >= model.StartDate.Date && e.Exam.ExamDate <= model.EndDate.Date);
}
else if (model.SearchType == "District")
{
    result = FindExams((e) => e.District.Name.Contains(model.SearchInput));
}
else if (model.SearchType == "ID")
{
    result = FindExams((e) => e.Student.ID.Contains(model.SearchInput));
}
else if (model.SearchType == "First Name")
{
    result = FindExams((e) => e.Student.FirstName.Contains(model.SearchInput));
}
else if (model.SearchType == "Last Name")
{
    result = FindExams((e) => e.Student.LastName.Contains(model.SearchInput));
}

return result.OrderByDescending(r => r.ExamDate);

切换语句

switch (model.SearchType)
{
    case "School":
        result = this.FindExams((e) => e.School.School_Name.Contains(model.SearchInput));
        break;
    case "ExamDate":
        result = FindExams((e) => e.Exam.ExamDate >= model.StartDate.Date && e.Exam.ExamDate <= model.EndDate.Date);
        break;
    case "District":
        result = this.FindExams((e) => e.District.Name.Contains(model.SearchInput));
        break;
    case "ID":
        result = this.FindExams((e) => e.Student.ID.Contains(model.SearchInput));
        break;
    case "First Name":
        result = this.FindExams((e) => e.Student.FirstName.Contains(model.SearchInput));
        break;
    case "Last Name":
        result = this.FindExams((e) => e.Student.LastName.Contains(model.SearchInput));
        break;
    case "Exam Id":
        int examId = int.Parse(model.SearchInput);
        result = this.FindExams((e) => e.Exam.Exam_Id == examId);
        break;
}

return result.OrderByDescending(r => r.ExamDate);

Answer 1

这两个代码段在以下几行不同：

else if (model.SearchType == "Exam Date")

和

case "ExamDate":

如您所见，它们检查两个不同的字符串。 应该是：

case "Exam Date":