c＃：Switch case：if（case :)

Question

這個問題對於回答或查看我以前關於break的問題的一些人可能看起來很熟悉;聲明。如果情況1得到滿足，我想做點什麼，如果情況2則要做其他事情。像下面這樣。任何人都可以指導我（如果可行的話），我可以如何實現我想要做的，而不必將我的if語句放在switch case中？

 switch (searchType) 
     { 
      case "SearchBooks": 
       Selenium.Type("//*[@id='SearchBooks_TextInput']", searchText); 
       Selenium.Click("//*[@id='SearchBooks_SearchBtn']"); 
       break; 

      case "SearchAuthors": 
       Selenium.Type("//*[@id='SearchAuthors_TextInput']", searchText); 
       Selenium.Click("//*[@id='SearchAuthors_SearchBtn']"); 
       break; 
     } 

     int count = int(Selenium.GetXpathCount("//[@id='Results_Table']"); 

     if case was "SearchBooks" 
     { 
      //do something 
     } 
     else if case was "SearchAuthors" 
     { 
      //do something else 
     } 

Answer 1

public enum MyEnumSearchTypes 
    { 
     SearchBooks, SearchAuthors, SearchSomethingElse 
    } 

    public void MyDoSomethingMethod(MyEnumSearchTypes searchType) 
    { 
     switch (searchType) 
     { 
      case MyEnumSearchTypes.SearchBooks: 
       Selenium.Type("//*[@id='SearchBooks_TextInput']", searchText); 
       Selenium.Click("//*[@id='SearchBooks_SearchBtn']"); 
      break; 

      case MyEnumSearchTypes.SearchAuthors: 
       Selenium.Type("//*[@id='SearchAuthors_TextInput']", searchText); 
       Selenium.Click("//*[@id='SearchAuthors_SearchBtn']"); 
      break; 
     }  

     if (searchType == MyEnumDefinedTypes.SearchBooks) 
     {  
      do something 
     }  

     else if (searchType == MyEnumDefinedTypes.SearchAuthors) 
     {  
      do something else 
     }    

     else 
     {  
      do nothing 
     }  
    }   

但是，我不知道爲什麼在switch語句添加的功能不符合您的需求？

Answer 2

if (searchType == "SearchAuthors") 

你不能做任何比這更好的。

Answer 3

如果在常見的兩種情況下的唯一路線是

int count = int(Selenium.GetXpathCount("//[@id='Results_Table']"); 

然後我就只寫了兩次。

int count; 
switch (searchType) 
{ 
    case "SearchBooks": 
     Selenium.Type("//*[@id='SearchBooks_TextInput']", searchText); 
     Selenium.Click("//*[@id='SearchBooks_SearchBtn']"); 
     count = int(Selenium.GetXpathCount("//[@id='Results_Table']"); 
     //do something 
     break; 

    case "SearchAuthors": 
     Selenium.Type("//*[@id='SearchAuthors_TextInput']", searchText); 
     Selenium.Click("//*[@id='SearchAuthors_SearchBtn']"); 
     count = int(Selenium.GetXpathCount("//[@id='Results_Table']"); 
     //do something else 
     break; 
} 

Answer 4

searchType將包含您需要的值。

所以，你可以有你目前的情況下發言，然後寫

if (searchType == "SearchBooks") 
// do something 
else if (searchType == "SearchAuthors") 
// do something else 

Answer 5

Action<int> myAction; 
    switch (searchType) 
     { 
      case "SearchBooks": 
       Selenium.Type("//*[@id='SearchBooks_TextInput']", searchText); 
       Selenium.Click("//*[@id='SearchBooks_SearchBtn']"); 
       // assign custom action 
       myAction = count => { /* the count is count */}; 
       break; 

      case "SearchAuthors": 
       Selenium.Type("//*[@id='SearchAuthors_TextInput']", searchText); 
       Selenium.Click("//*[@id='SearchAuthors_SearchBtn']"); 
       // assign custom action 
       myAction = count => { /* the count is count */}; 
       break; 
      default: 
       throw new NotSupportedException(); 
     } 

     int count = int(Selenium.GetXpathCount("//[@id='Results_Table']"); 
     // invoke custom action 
     myAction(count); 

Answer 6

你可以這樣做了許多不同的方式，這取決於你的理由不想包括在case語句代碼。其他回答者有非常好的建議。在我看來，這個代碼是叫一個面向對象的方法：

var search = GetSearch(searchType); 
search.PerformSearch(searchText); 
int count = (int)Selenium.GetXpathCount("//[@id='Results_Table']"); 
search.DoSomething(count); 

... 

public ISearch GetSearch(string searchType) 
{ 
    switch (searchType) 
    { 
     case "SearchBooks": return new SearchBooks(); 
     case "SearchAuthors": return new SearchAuthors(); 
     default: 
      throw new ArgumentException(
       string.Format("Invalid searchtype \"{0}\"", searchType), 
       "searchType"); 
    } 
} 


public interface ISearch 
{ 
    void PerformSearch(string searchText); 
    void DoSomething(); 
} 

public class SearchBooks : ISearch 
{ 
    public void PerformSearch(string searchText) 
    { 
     Selenium.Type("//*[@id='SearchBooks_TextInput']", searchText); 
     Selenium.Click("//*[@id='SearchBooks_SearchBtn']"); 
    } 

    void DoSomething() 
    { 
     // do something 
    } 
} 

public class SearchAuthors : ISearch 
{ 
    public void PerformSearch(string searchText) 
    { 
     Selenium.Type("//*[@id='SearchAuthors_TextInput']", searchText); 
     Selenium.Click("//*[@id='SearchBooks_SearchBtn']"); 
    } 

    void DoSomething() 
    { 
     // do something else 
    } 
} 

Answer 7

如果您爲了清晰起見而希望擁有兩批開關語句，請先將字符串轉換爲枚舉，然後從此處繼續。

如果您有興趣這樣做，我可以進一步填寫答案。讓我知道。

public enum SearchTypeEnum{None,SearchBooks,SearchAuthors} 

var searchType = (SearchTypeEnum)Enum.Parse(typeof(SearchTypeEnum), searchTypeString); 

switch (searchType){  
case SearchTypeEnum.SearchBooks: 
... 

switch (searchType){  
case SearchTypeEnum.SearchBooks: 
... 

Answer 8

打電話給我極客。 :)

Selenium.Type(string.Format(@"//*[@id='{0}_TextInput']", searchType), searchText); 
Selenium.Click(string.Format(@"//*[@id='{0}_SearchBtn']", searchType)); 

並保存case語句。

現在，顯然，這隻適用於searchType值始終與實際元素ID相對應的情況。