在C＃中接受字符串的TrimEnd或TrimStart方法？

Question

請問C＃有一個TrimEnd或TrimStart方法有一個string參數嗎？ 不，即使我們使用string.ToCharArray()，如TrimEnd(str.ToCharArray());，它表現不佳。

例如：

string sam = "Sammy"; 
sam = TrimEndOrStart(sam, "my", true); 

sam應該等於"Sam"

Answer 1

/// <summary> 
/// Does a nice trim for your string 
/// </summary> 
/// <param name="Subject">The subject</param> 
/// <param name="Search">What to trim on the string</param> 
/// <param name="TrimEnd">If set to true we trim the end</param> 
/// <returns></returns> 
public static string TrimEndOrStart(string Subject, string Search, bool TrimEnd) 
{ 
    if (TrimEnd) 
    { 
     if (Subject.EndsWith(Search) == false) 
     { 
      return Subject; 
     } 

     Subject = ReverseString(Subject); 

     Start: 
      string[] Array1 = Subject.Split(new string[] { ReverseString(Search) }, 2, StringSplitOptions.RemoveEmptyEntries); 

     if (Array1.Length == 1) 
     { 
      if (Subject.Equals(Array1[0], StringComparison.Ordinal) == false) 
      { 
       Subject = Array1[0]; 
       goto Start; 
      } 
     } 

     Subject = StaticMethods.ReverseString(Subject); 
     return Subject; 
    } 

    if (Subject.StartsWith(Search) == false) 
    { 
     return Subject; 
    } 

    Start2: 
     string[] Array2 = Subject.Split(new string[] { Search }, 2, StringSplitOptions.RemoveEmptyEntries); 

    if (Subject.Equals(Array2[0], StringComparison.Ordinal) == false) 
    { 
     Subject = Array2[0]; 
     goto Start2; 
    } 

    return Subject; 
} 


/// <summary> 
/// Reverses a string array 
/// </summary> 
/// <param name="StrArray"></param> 
/// <returns></returns> 
public static string ReverseString(string Str) 
{ 
    char[] ObjectArr = Str.ToCharArray(); 
    char[] NewObjectArr = new char[ObjectArr.Length]; 
    int counter = 0; 

    for (int index = ObjectArr.Length - 1; index > -1; index--) 
    { 
     NewObjectArr[counter] = ObjectArr[index]; 
     counter = counter + 1; 
    } 

    Str = ""; 
    StringBuilder StrBu = new StringBuilder(1000); 

    for (int index = 0; index < NewObjectArr.Length; index++) 
    { 
     StrBu.Append(NewObjectArr[index]); 
    } 

    Str = StrBu.ToString(); 
    return Str; 
} 

Answer 2

您可以使用StartWith/ENDWITH像：

static class StringTrimExtension { 
    public static string TrimStart(this string value, string toTrim) { 
     if (value.StartsWith(toTrim)) { 
      int startIndex = toTrim.Length; 
      return value.Substring(startIndex); 
     } 
     return value; 
    } 

    public static string TrimEnd(this string value, string toTrim) { 
     if (value.EndsWith(toTrim)) { 
      int startIndex = toTrim.Length; 
      return value.Substring(0, value.Length - startIndex); 
     } 
     return value; 
    } 
} 

static void Main(string[] args) { 
     string s = "Sammy"; 
     Console.WriteLine(s); 
     string trimEnd = s.TrimEnd("my"); 
     string trimStart = s.TrimStart("Sa"); 
     Console.WriteLine(trimEnd); 
     Console.WriteLine(trimStart); 
     Console.ReadLine(); 
} 

如果你有需要IGNORECASE可以實現並覆蓋您的修剪方法並使用覆蓋StartsWith/EndsWith方法。

編輯： 遞歸：

static class StringTrimExtension { 
    public static string TrimStartRecursive(this string value, string toTrim) { 
     string result = value; 
     while (TrimStart(result, toTrim, out result)) {} 
     return result; 
    } 

    public static string TrimEndRecursive(this string value, string toTrim) { 
     string result = value; 
     while (TrimEnd(result, toTrim, out result)) { } 
     return result; 
    } 

    public static string TrimStart(this string value, string toTrim) { 
     string result; 
     TrimStart(value, toTrim, out result); 
     return result; 
    } 

    public static string TrimEnd(this string value, string toTrim) { 
     string result; 
     TrimEnd(value, toTrim, out result); 
     return result; 
    } 

    public static bool TrimStart(this string value, string toTrim, out string result) { 
     result = value; 
     if (value.StartsWith(toTrim)) { 
      int startIndex = toTrim.Length; 
      result= value.Substring(startIndex); 
      return true; 
     } 
     return false; 
    } 

    public static bool TrimEnd(this string value, string toTrim, out string result) { 
     result = value; 
     if (value.EndsWith(toTrim)) { 
      int startIndex = toTrim.Length; 
      result = value.Substring(0, value.Length - startIndex); 
      return true; 
     } 
     return false; 
    } 
} 

    static void Main(string[] args) { 
     string s = "Sammymymymy"; 
     Console.WriteLine(s); 
     string trimEnd = s.TrimEndRecursive("my"); 
     string trimStart = s.TrimStartRecursive("Sa"); 
     Console.WriteLine(trimEnd); 
     Console.WriteLine(trimStart); 
     Console.ReadLine(); 
    }