String.TrimStart Yöntem

public:
 System::String ^ TrimStart();

public string TrimStart ();

member this.TrimStart : unit -> string

Public Function TrimStart () As String

Döndürülenler

String

Tüm beyaz boşluk karakterlerinden sonra kalan dize, geçerli dizenin başından kaldırılır.The string that remains after all white-space characters are removed from the start of the current string. Geçerli örnekten hiçbir karakter kırpılabilecek ise, yöntem geçerli örneği değişmeden döndürür.If no characters can be trimmed from the current instance, the method returns the current instance unchanged.

Açıklamalar

TrimStartYöntemi, geçerli dizeden önde gelen boşluk karakterlerinden kaldırır.The TrimStart method removes from the current string all leading white-space characters. Boşluk olmayan bir karakter ile karşılaşıldığında trim işlemi durduruluyor.The trim operation stops when a non white-space character is encountered. Örneğin, geçerli dize "abc xyz" ise, TrimStart Yöntem "abc xyz" döndürür.For example, if the current string is " abc xyz ", the TrimStart method returns "abc xyz ".

public:
 System::String ^ TrimStart(... cli::array <char> ^ trimChars);

public string TrimStart (params char[] trimChars);

public string TrimStart (params char[]? trimChars);

member this.TrimStart : char[] -> string

Public Function TrimStart (ParamArray trimChars As Char()) As String

Parametreler

Döndürülenler

String

Parametresindeki tüm karakter oluşumlarından sonra kalan dize, trimChars geçerli dizenin başından kaldırılır.The string that remains after all occurrences of characters in the trimChars parameter are removed from the start of the current string. trimCharsİse null veya boş bir diziyse, bunun yerine boşluk karakterleri kaldırılır.If trimChars is null or an empty array, white-space characters are removed instead. Geçerli örnekten hiçbir karakter kırpılabilecek ise, yöntem geçerli örneği değişmeden döndürür.If no characters can be trimmed from the current instance, the method returns the current instance unchanged.

Örnekler

Aşağıdaki örnek, yönteminin temel işlevlerini göstermektedir TrimStart :The following example demonstrates the basic functionality of the TrimStart method:

// TrimStart examples
string lineWithLeadingSpaces = "   Hello World!";
string lineWithLeadingSymbols = "$$$$Hello World!";
string lineWithLeadingUnderscores = "_____Hello World!";
string lineWithLeadingLetters = "xxxxHello World!";
string lineAfterTrimStart = string.Empty;

// Make it easy to print out and work with all of the examples
string[] lines = { lineWithLeadingSpaces, lineWithLeadingSymbols, lineWithLeadingUnderscores, lineWithLeadingLetters };

foreach (var line in lines)
{
    Console.WriteLine($"This line has leading characters: {line}");
}
// Output:
// This line has leading characters:    Hello World!
// This line has leading characters: $$$$Hello World!
// This line has leading characters: _____Hello World!
// This line has leading characters: xxxxHello World!

// A basic demonstration of TrimStart in action
lineAfterTrimStart = lineWithLeadingSpaces.TrimStart(' ');
Console.WriteLine($"This is the result after calling TrimStart: {lineAfterTrimStart}");
// This is the result after calling TrimStart: Hello World!   

// Since TrimStart accepts a character array of leading items to be removed as an argument,
// it's possible to do things like trim multiple pieces of data that each have different 
// leading characters,
foreach (var lineToEdit in lines)
{
    Console.WriteLine(lineToEdit.TrimStart(' ', '$', '_', 'x'));
}
// Result for each: Hello World!

// or handle pieces of data that have multiple kinds of leading characters 
var lineToBeTrimmed = "__###__ John Smith";
lineAfterTrimStart = lineToBeTrimmed.TrimStart('_', '#', ' ');
Console.WriteLine(lineAfterTrimStart);
// Result: John Smith

Public Sub Main()
   ' TrimStart Examples
   Dim lineWithLeadingSpaces as String = "   Hello World!"
   Dim lineWithLeadingSymbols as String = "$$$$Hello World!"
   Dim lineWithLeadingUnderscores as String = "_____Hello World!"
   Dim lineWithLeadingLetters as String = "xxxxHello World!"
   Dim lineAfterTrimStart = String.Empty

   ' Make it easy to print out and work with all of the examples
   Dim lines As String() = { lineWithLeadingSpaces, line lineWithLeadingSymbols, lineWithLeadingUnderscores, lineWithLeadingLetters }

   For Each line As String in lines
     Console.WriteLine($"This line has leading characters: {line}")
   Next
   ' Output:
   ' This line has leading characters:    Hello World!
   ' This line has leading characters: $$$$Hello World!
   ' This line has leading characters: _____Hello World!
   ' This line has leading characters: xxxxHello World!

   Console.WriteLine($"This line has leading spaces: {lineWithLeadingSpaces}")
   ' This line has leading spaces:   Hello World!

   ' A basic demonstration of TrimStart in action
   lineAfterTrimStart = lineWithLeadingSpaces.TrimStart(" "c)
   Console.WriteLine($"This is the result after calling TrimStart: {lineAfterTrimStart}")
   ' This is the result after calling TrimStart: Hello World!

   ' Since TrimStart accepts a character array of leading items to be removed as an argument,
   ' it's possible to do things like trim multiple pieces of data that each have different 
   ' leading characters,
   For Each lineToEdit As String in lines
     Console.WriteLine(lineToEdit.TrimStart(" "c, "$"c, "_"c, "x"c ))
   Next
   ' Result for each: Hello World!

   ' or handle pieces of data that have multiple kinds of leading characters
   Dim lineToBeTrimmed as String = "__###__ John Smith"
   lineAfterTrimStart = lineToBeTrimmed.TrimStart("_"c , "#"c , " "c)
   Console.WriteLine(lineAfterTrimStart)
   ' Result: John Smith

 End Sub

Aşağıdaki örnek, TrimStart kaynak kodu satırlarından boşluk ve açıklama karakterlerini kırpmak için yöntemini kullanır.The following example uses the TrimStart method to trim white space and comment characters from lines of source code. StripCommentsYöntemi, bir çağrısını sarmalanmış TrimStart ve bir boşluk ve açıklama karakteri içeren bir karakter dizisine geçirir ve bu, Visual Basic bir kesme işareti (') ve C# içinde bir eğik çizgi (/) olur.The StripComments method wraps a call to TrimStart and passes it a character array that contains a space and the comment character, which is an apostrophe ( ' ) in Visual Basic and a slash ( / ) in C#. TrimStartYöntemi, bir dizenin bir yorum olup olmadığını değerlendirirken öndeki boşluğu kaldırmak için de çağrılır.The TrimStart method is also called to remove leading white space when evaluating whether a string is a comment.

public static string[] StripComments(string[] lines)
{
    List<string> lineList = new List<string>();
    foreach (string line in lines)
    {
        if (line.TrimStart(' ').StartsWith("//"))
            lineList.Add(line.TrimStart(' ', '/'));
    }
    return lineList.ToArray();
}

Public Shared Function StripComments(lines() As String) As String()
   Dim lineList As New List(Of String)
   For Each line As String In lines
      If line.TrimStart(" "c).StartsWith("'") Then
         linelist.Add(line.TrimStart("'"c, " "c))
      End If
   Next
   Return lineList.ToArray()
End Function   

Aşağıdaki örnek daha sonra yöntemine bir çağrı gösterir StripComments .The following example then illustrates a call to the StripComments method.

public static void Main()
{
    string[] lines = {"using System;",
                   "",
                   "public class HelloWorld",
                   "{",
                   "   public static void Main()",
                   "   {",
                   "      // This code displays a simple greeting",
                   "      // to the console.",
                   "      Console.WriteLine(\"Hello, World.\");",
                   "   }",
                   "}"};
    Console.WriteLine("Before call to StripComments:");
    foreach (string line in lines)
        Console.WriteLine("   {0}", line);

    string[] strippedLines = StripComments(lines);
    Console.WriteLine("After call to StripComments:");
    foreach (string line in strippedLines)
        Console.WriteLine("   {0}", line);
}
// This code produces the following output to the console:
//    Before call to StripComments:
//       using System;
//   
//       public class HelloWorld
//       {
//           public static void Main()
//           {
//               // This code displays a simple greeting
//               // to the console.
//               Console.WriteLine("Hello, World.");
//           }
//       }  
//    After call to StripComments:
//       This code displays a simple greeting
//       to the console.

Public Shared Sub Main()
   Dim lines() As String = {"Public Module HelloWorld", _
                            "   Public Sub Main()", _
                            "      ' This code displays a simple greeting", _
                            "      ' to the console.", _
                            "      Console.WriteLine(""Hello, World."")", _
                            "   End Sub", _
                            " End Module"}
   Console.WriteLine("Code before call to StripComments:")
   For Each line As String In lines
      Console.WriteLine("   {0}", line)                         
   Next                            
   
   Dim strippedLines() As String = StripComments(lines) 
   Console.WriteLine("Code after call to StripComments:")
   For Each line As String In strippedLines
      Console.WriteLine("   {0}", line)                         
   Next                            
End Sub
' This code produces the following output to the console:
'    Code before call to StripComments:
'       Public Module HelloWorld
'          Public Sub Main()
'             ' This code displays a simple greeting
'             ' to the console.
'             Console.WriteLine("Hello, World.")
'          End Sub
'       End Module
'    Code after call to StripComments:
'       This code displays a simple greeting
'       to the console.   

Açıklamalar

TrimStart(System.Char[])Yöntemi, geçerli dizeden, parametresindeki tüm baştaki karakterleri kaldırır trimChars .The TrimStart(System.Char[]) method removes from the current string all leading characters that are in the trimChars parameter. İçinde olmayan bir karakter ile karşılaşıldığında trim işlemi durduruluyor trimChars .The trim operation stops when a character that is not in trimChars is encountered. Örneğin, geçerli dize "123abc456xyz789" ve trimChars "1" ile "9" arasındaki rakamları içeriyorsa, TrimStart(System.Char[]) Yöntem "abc456xyz789" döndürür.For example, if the current string is "123abc456xyz789" and trimChars contains the digits from "1" through "9", the TrimStart(System.Char[]) method returns "abc456xyz789".

Arayanlara Notlar

.NET Framework 3,5 SP1 ve önceki sürümleri, bu yöntemin bir trimChars veya boş dizi olarak kırpduğu boşluk karakterlerinin dahili bir listesini tutar null .The .NET Framework 3.5 SP1 and earlier versions maintains an internal list of white-space characters that this method trims if trimChars is null or an empty array. .NET Framework 4, trimChars null veya boş bir dizi ise, yöntemi tüm Unicode boşluk karakterlerini kırpar (diğer bir deyişle, true yönteme geçirildiğinde bir dönüş değeri üreten karakterler IsWhiteSpace(Char) ).Starting with the .NET Framework 4, if trimChars is null or an empty array, the method trims all Unicode white-space characters (that is, characters that produce a true return value when they are passed to the IsWhiteSpace(Char) method). Bu değişiklik nedeniyle, Trim() .NET Framework 3,5 SP1 ve önceki sürümlerindeki yöntem iki karakteri, sıfır GENIŞLIK alanını (u + 200B) ve sıfır GENIŞLIK yok (u + FEFF), Trim() .NET Framework 4 ve sonraki sürümlerindeki yöntemin KALDıRMADıĞı bir yere kaldırır.Because of this change, the Trim() method in the .NET Framework 3.5 SP1 and earlier versions removes two characters, ZERO WIDTH SPACE (U+200B) and ZERO WIDTH NO-BREAK SPACE (U+FEFF), that the Trim() method in the .NET Framework 4 and later versions does not remove. Ayrıca, Trim() .NET Framework 3,5 SP1 ve önceki sürümlerindeki Yöntem üç Unicode boşluk karakterini kırpmaz: Moğolca sesli harf ayırıcı (u + 180E), dar yok-kesme alanı (u + 202F) ve orta MATEMATIKSEL boşluk (u + 205F).In addition, the Trim() method in the .NET Framework 3.5 SP1 and earlier versions does not trim three Unicode white-space characters: MONGOLIAN VOWEL SEPARATOR (U+180E), NARROW NO-BREAK SPACE (U+202F), and MEDIUM MATHEMATICAL SPACE (U+205F).

Ayrıca bkz.

• Char
• Trim(Char[])
• TrimEnd(Char[])
• IsWhiteSpace(Char)

public:
 System::String ^ TrimStart(char trimChar);

public string TrimStart (char trimChar);

member this.TrimStart : char -> string

Public Function TrimStart (trimChar As Char) As String

Parametreler

Döndürülenler

String

Tüm karakter oluşumlarından sonra kalan dize, trimChar geçerli dizenin başından kaldırılır.The string that remains after all occurrences of the trimChar character are removed from the start of the current string. Geçerli örnekten hiçbir karakter kırpılabilecek ise, yöntem geçerli örneği değişmeden döndürür.If no characters can be trimmed from the current instance, the method returns the current instance unchanged.

Açıklamalar

TrimStart(System.Char)Yöntemi, geçerli dizeden tüm önde gelen karakterlerden kaldırır trimChar .The TrimStart(System.Char) method removes from the current string all leading trimChar characters. Bir karakter ile karşılaşıldığında trim işlemi durduruluyor trimChar .The trim operation stops when a character that is not trimChar is encountered. Örneğin, trimChar - ve geçerli dize "---abc---xyz----" ise, TrimStart(System.Char) yöntem "abc---xyz----" döndürür.For example, if trimChar is - and the current string is "---abc---xyz----", the TrimStart(System.Char) method returns "abc---xyz----".