Capture.Value 屬性

參考

定義

命名空間:: System.Text.RegularExpressions

組件:: System.Text.RegularExpressions.dll

組件:: System.dll

組件:: netstandard.dll

Source:: Capture.cs

Source:: Capture.cs

Source:: Capture.cs

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

從輸入字串取得擷取的子字串。

public:
 property System::String ^ Value { System::String ^ get(); };

public string Value { get; }

member this.Value : string

Public ReadOnly Property Value As String

屬性值

String

比對所擷取的子字串。

範例

下列範例會定義正則運算式，此正則運算式符合不含標點符號的句子，但句點 (除外」。) 。屬性 Match.Value 會顯示結果字串，此字串是由每個相符的句子所組成。屬性 Group.Value 會顯示每個擷取群組的結果字串;它是由該擷取群組所擷取的最後一個字串所組成。屬性 Capture.Value 會顯示每個擷取的結果字串。

using System;
using System.Text.RegularExpressions;

public class Example
{
   public static void Main()
   {
      string input = "Yes. This dog is very friendly.";
      string pattern = @"((\w+)[\s.])+";
      foreach (Match match in Regex.Matches(input, pattern))
      {
         Console.WriteLine("Match: {0}", match.Value);
         for (int groupCtr = 0; groupCtr < match.Groups.Count; groupCtr++)
         {
            Group group = match.Groups[groupCtr];
            Console.WriteLine("   Group {0}: {1}", groupCtr, group.Value);
            for (int captureCtr = 0; captureCtr < group.Captures.Count; captureCtr++)
               Console.WriteLine("      Capture {0}: {1}", captureCtr, 
                                 group.Captures[captureCtr].Value);
         }                      
      }
   }
}
// The example displays the following output:
//       Match: Yes.
//          Group 0: Yes.
//             Capture 0: Yes.
//          Group 1: Yes.
//             Capture 0: Yes.
//          Group 2: Yes
//             Capture 0: Yes
//       Match: This dog is very friendly.
//          Group 0: This dog is very friendly.
//             Capture 0: This dog is very friendly.
//          Group 1: friendly.
//             Capture 0: This
//             Capture 1: dog
//             Capture 2: is
//             Capture 3: very
//             Capture 4: friendly.
//          Group 2: friendly
//             Capture 0: This
//             Capture 1: dog
//             Capture 2: is
//             Capture 3: very
//             Capture 4: friendly

Imports System.Text.RegularExpressions

Module Example
   Public Sub Main()
      Dim input As String = "Yes. This dog is very friendly."
      Dim pattern As String = "((\w+)[\s.])+"
      For Each match As Match In Regex.Matches(input, pattern)
         Console.WriteLine("Match: {0}", match.Value)
         For groupCtr As Integer = 0 To match.Groups.Count - 1
            Dim group As Group = match.Groups(groupCtr)
            Console.WriteLine("   Group {0}: {1}", groupCtr, group.Value)
            For captureCtr As Integer = 0 To group.Captures.Count - 1
               Console.WriteLine("      Capture {0}: {1}", captureCtr, _
                                 group.Captures(captureCtr).Value)
            Next
         Next                      
      Next
   End Sub
End Module
' The example displays the following output:
'       Match: Yes.
'          Group 0: Yes.
'             Capture 0: Yes.
'          Group 1: Yes.
'             Capture 0: Yes.
'          Group 2: Yes
'             Capture 0: Yes
'       Match: This dog is very friendly.
'          Group 0: This dog is very friendly.
'             Capture 0: This dog is very friendly.
'          Group 1: friendly.
'             Capture 0: This
'             Capture 1: dog
'             Capture 2: is
'             Capture 3: very
'             Capture 4: friendly.
'          Group 2: friendly
'             Capture 0: This
'             Capture 1: dog
'             Capture 2: is
'             Capture 3: very
'             Capture 4: friendly

規則運算式模式 ((\w+)[\s.])+ 的定義如下表所示。請注意，在此正則運算式中，會將數量詞 (+) 套用至整個正則運算式。

模式	描述
`(\w+)`	比對一個或多個文字字元。這是第二個擷取群組。
`[\s.])`	比對空白字元或句點 (「。」) 。
`((\w+)[\s.])`	比對一或多個文字字元，後面接著空白字元或句號 (「。」) 。這是第一個擷取群組。
`((\w+)[\s.])+`	比對一或多個出現的單字字元或字元，後面接著空白字元或句號 (」。) 。

在此範例中，輸入字串是由兩個句子所組成。如輸出所示，第一個句子只包含一個單字，因此 CaptureCollection 物件具有單 Capture 一物件，代表與 Group 物件相同的擷取。第二個句子包含多個單字，因此 Group 物件只包含最後一個相符子運算式的相關資訊。代表第一個擷取的群組 1 包含句尾句中的最後一個字。代表第二個擷取的群組 2 包含句子中的最後一個字。不過， Capture 群組物件 CaptureCollection 中的物件會擷取每個子運算式相符專案。 Capture第一個擷取群組中擷取的物件包含每個擷取的文字和空白字元或句點的相關資訊。第 Capture 二個擷取群組中擷取的物件包含每個擷取文字的相關資訊。

下列範例會使用正則運算式模式 ^([a-z]+)(\d+)*\.([a-z]+(\d)*)$ ，比對由句號分隔兩個部分的產品名稱。這兩個部分都包含字母字元，後面接著選擇性數位。因為第一個輸入字串不符合模式，所以傳 System.Text.RegularExpressions.Match 回之物件的 Value 屬性值為 String.Empty 。同樣地，當正則運算式模式無法比對擷取群組時，對應 Group 物件的 Value 屬性值為 String.Empty 。

using System;
using System.Text.RegularExpressions;

public class Example
{
   public static void Main()
   {
      String pattern = @"^([a-z]+)(\d+)?\.([a-z]+(\d)*)$";
      String[] values = { "AC10", "Za203.CYM", "XYZ.CoA", "ABC.x170" };   
      foreach (var value in values) {
         Match m = Regex.Match(value, pattern, RegexOptions.IgnoreCase);
         if (m.Success) {
            Console.WriteLine("Match: '{0}'", m.Value);
            Console.WriteLine("   Number of Capturing Groups: {0}", 
                              m.Groups.Count);
            for (int gCtr = 0; gCtr < m.Groups.Count; gCtr++) {
               Group group = m.Groups[gCtr];
               Console.WriteLine("      Group {0}: {1}", gCtr, 
                                 group.Value == "" ? "<empty>" : "'" + group.Value + "'");   
               Console.WriteLine("         Number of Captures: {0}", 
                                 group.Captures.Count);
           
               for (int cCtr = 0; cCtr < group.Captures.Count; cCtr++) 
                  Console.WriteLine("            Capture {0}: {1}", 
                                    cCtr, group.Captures[cCtr].Value);
            }
         } 
         else {
            Console.WriteLine("No match for {0}: Match.Value is {1}", 
                              value, m.Value == String.Empty ? "<empty>" : m.Value);
         }
      }
   }
}
// The example displays the following output:
//       No match for AC10: Match.Value is <empty>
//       Match: 'Za203.CYM'
//          Number of Capturing Groups: 5
//             Group 0: 'Za203.CYM'
//                Number of Captures: 1
//                   Capture 0: Za203.CYM
//             Group 1: 'Za'
//                Number of Captures: 1
//                   Capture 0: Za
//             Group 2: '203'
//                Number of Captures: 1
//                   Capture 0: 203
//             Group 3: 'CYM'
//                Number of Captures: 1
//                   Capture 0: CYM
//             Group 4: <empty>
//                Number of Captures: 0
//       Match: 'XYZ.CoA'
//          Number of Capturing Groups: 5
//             Group 0: 'XYZ.CoA'
//                Number of Captures: 1
//                   Capture 0: XYZ.CoA
//             Group 1: 'XYZ'
//                Number of Captures: 1
//                   Capture 0: XYZ
//             Group 2: <empty>
//                Number of Captures: 0
//             Group 3: 'CoA'
//                Number of Captures: 1
//                   Capture 0: CoA
//             Group 4: <empty>
//                Number of Captures: 0
//       Match: 'ABC.x170'
//          Number of Capturing Groups: 5
//             Group 0: 'ABC.x170'
//                Number of Captures: 1
//                   Capture 0: ABC.x170
//             Group 1: 'ABC'
//                Number of Captures: 1
//                   Capture 0: ABC
//             Group 2: <empty>
//                Number of Captures: 0
//             Group 3: 'x170'
//                Number of Captures: 1
//                   Capture 0: x170
//             Group 4: '0'
//                Number of Captures: 3
//                   Capture 0: 1
//                   Capture 1: 7
//                   Capture 2: 0

Imports System.Text.RegularExpressions

Module Example
   Public Sub Main()
      Dim pattern As String = "^([a-z]+)(\d+)?\.([a-z]+(\d)*)$"
      Dim values() As String = { "AC10", "Za203.CYM", "XYZ.CoA", "ABC.x170" }   
      For Each value In values
         Dim m As Match = Regex.Match(value, pattern, RegexOptions.IgnoreCase)
         If m.Success Then
            Console.WriteLine("Match: '{0}'", m.Value)
            Console.WriteLine("   Number of Capturing Groups: {0}", 
                              m.Groups.Count)
            For gCtr As Integer = 0 To m.Groups.Count - 1
               Dim group As Group = m.Groups(gCtr)
               Console.WriteLine("      Group {0}: {1}", gCtr, 
                                 If(group.Value = "", "<empty>", "'" + group.Value + "'"))   
               Console.WriteLine("         Number of Captures: {0}", 
                                 group.Captures.Count)
           
               For cCtr As Integer = 0 To group.Captures.Count - 1
                  Console.WriteLine("            Capture {0}: {1}", 
                                    cCtr, group.Captures(cCtr).Value)
               Next
            Next
         Else
            Console.WriteLine("No match for {0}: Match.Value is {1}", 
                              value, If(m.Value = String.Empty, "<empty>", m.Value))
         End If
      Next    
   End Sub
End Module
' The example displays the following output:
'       No match for AC10: Match.Value is <empty>
'       Match: 'Za203.CYM'
'          Number of Capturing Groups: 5
'             Group 0: 'Za203.CYM'
'                Number of Captures: 1
'                   Capture 0: Za203.CYM
'             Group 1: 'Za'
'                Number of Captures: 1
'                   Capture 0: Za
'             Group 2: '203'
'                Number of Captures: 1
'                   Capture 0: 203
'             Group 3: 'CYM'
'                Number of Captures: 1
'                   Capture 0: CYM
'             Group 4: <empty>
'                Number of Captures: 0
'       Match: 'XYZ.CoA'
'          Number of Capturing Groups: 5
'             Group 0: 'XYZ.CoA'
'                Number of Captures: 1
'                   Capture 0: XYZ.CoA
'             Group 1: 'XYZ'
'                Number of Captures: 1
'                   Capture 0: XYZ
'             Group 2: <empty>
'                Number of Captures: 0
'             Group 3: 'CoA'
'                Number of Captures: 1
'                   Capture 0: CoA
'             Group 4: <empty>
'                Number of Captures: 0
'       Match: 'ABC.x170'
'          Number of Capturing Groups: 5
'             Group 0: 'ABC.x170'
'                Number of Captures: 1
'                   Capture 0: ABC.x170
'             Group 1: 'ABC'
'                Number of Captures: 1
'                   Capture 0: ABC
'             Group 2: <empty>
'                Number of Captures: 0
'             Group 3: 'x170'
'                Number of Captures: 1
'                   Capture 0: x170
'             Group 4: '0'
'                Number of Captures: 3
'                   Capture 0: 1
'                   Capture 1: 7
'                   Capture 2: 0

規則運算式模式的定義如下表所示：

模式	描述
`^`	從字串的開頭開始比對。
`([a-z]+)`	比對一或多個從到 z 的任何字元。因為正則運算式引擎是傳遞 RegexOptions.IgnoreCase 選項，所以此比較不區分大小寫。這是第一個擷取群組。
`(\d+)?`	比對零或一次出現一或多個十進位數。這是第二個擷取群組。
`\.`	比對常值句號字元。
`([a-z]+`	比對一或多個從到 z 的任何字元。此比較不區分大小寫。
`(\d)*`	比對零個或多個十進位數字。單一相符的數位是第四個擷取群組。
`([a-z]+(\d)*)`	比對從到 z 的一或多個字母字元，後面接著零、一或多個十進位數。這是第四個擷取群組。
`$`	結束字串結尾的相符專案。

備註

如果對或方法的 Regex.Match 呼叫找不到相符專案，則傳 Match.Value 回屬性的值為 String.Empty 。 Match.NextMatch 如果正則運算式引擎無法比對擷取群組。傳 Group.Value 回屬性的值是 String.Empty 。如需圖例，請參閱第二個範例。

適用於

Capture.Value 屬性

定義

屬性值

範例

備註

適用於

意見反應

其他資源