StringSplitOptions 列舉

定義

命名空間:

System

組件:

netstandard.dll, System.Runtime.dll

指定適用 Split 方法多載的選項，例如省略傳回陣列的空子字串，或修剪子字串的空白字元。

此列舉支援其成員值的位元組合。

C#

[System.Flags]
public enum StringSplitOptions

繼承

Object

ValueType

Enum

StringSplitOptions

屬性

FlagsAttribute

欄位

名稱	值	Description
None	0	分割字串時，請使用預設選項。
RemoveEmptyEntries	1	省略結果包含空字串的陣列元素。 如果 RemoveEmptyEntries 和 TrimEntries 一起指定，則只包含空白字元的子字串也會從結果中移除。
TrimEntries	2	修剪結果中每個子字串的空白字元。 此欄位僅適用于 .NET 5 和更新版本。 如果 RemoveEmptyEntries 和 TrimEntries 一起指定，則只包含空白字元的子字串也會從結果中移除。

範例

下列範例示範如何使用 StringSplitOptions 列舉來包含或排除 方法所產生的 String.Split 子字串：

C#

// This example demonstrates the String.Split() methods that use
// the StringSplitOptions enumeration.

// Example 1: Split a string delimited by characters
Console.WriteLine("1) Split a string delimited by characters:\n");

string s1 = ",ONE,, TWO,, , THREE,,";
char[] charSeparators = new char[] { ',' };
string[] result;

Console.WriteLine($"The original string is: \"{s1}\".");
Console.WriteLine($"The delimiter character is: '{charSeparators[0]}'.\n");

// Split the string and return all elements
Console.WriteLine("1a) Return all elements:");
result = s1.Split(charSeparators, StringSplitOptions.None);
Show(result);

// Split the string and return all elements with whitespace trimmed
Console.WriteLine("1b) Return all elements with whitespace trimmed:");
result = s1.Split(charSeparators, StringSplitOptions.TrimEntries);
Show(result);

// Split the string and return all non-empty elements
Console.WriteLine("1c) Return all non-empty elements:");
result = s1.Split(charSeparators, StringSplitOptions.RemoveEmptyEntries);
Show(result);

// Split the string and return all non-whitespace elements with whitespace trimmed
Console.WriteLine("1d) Return all non-whitespace elements with whitespace trimmed:");
result = s1.Split(charSeparators, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
Show(result);


// Split the string into only two elements, keeping the remainder in the last match
Console.WriteLine("1e) Split into only two elements:");
result = s1.Split(charSeparators, 2, StringSplitOptions.None);
Show(result);

// Split the string into only two elements with whitespace trimmed, keeping the remainder in the last match
Console.WriteLine("1f) Split into only two elements with whitespace trimmed:");
result = s1.Split(charSeparators, 2, StringSplitOptions.TrimEntries);
Show(result);

// Split the string into only two non-empty elements, keeping the remainder in the last match
Console.WriteLine("1g) Split into only two non-empty elements:");
result = s1.Split(charSeparators, 2, StringSplitOptions.RemoveEmptyEntries);
Show(result);

// Split the string into only two non-whitespace elements with whitespace trimmed, keeping the remainder in the last match
Console.WriteLine("1h) Split into only two non-whitespace elements with whitespace trimmed:");
result = s1.Split(charSeparators, 2, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
Show(result);


// Example 2: Split a string delimited by another string
Console.WriteLine("2) Split a string delimited by another string:\n");

string s2 = "[stop]" +
            "ONE[stop] [stop]" +
            "TWO  [stop][stop]  [stop]" +
            "THREE[stop][stop]  ";
string[] stringSeparators = new string[] { "[stop]" };

Console.WriteLine($"The original string is: \"{s2}\".");
Console.WriteLine($"The delimiter string is: \"{stringSeparators[0]}\".\n");

// Split the string and return all elements
Console.WriteLine("2a) Return all elements:");
result = s2.Split(stringSeparators, StringSplitOptions.None);
Show(result);

// Split the string and return all elements with whitespace trimmed
Console.WriteLine("2b) Return all elements with whitespace trimmed:");
result = s2.Split(stringSeparators, StringSplitOptions.TrimEntries);
Show(result);

// Split the string and return all non-empty elements
Console.WriteLine("2c) Return all non-empty elements:");
result = s2.Split(stringSeparators, StringSplitOptions.RemoveEmptyEntries);
Show(result);

// Split the string and return all non-whitespace elements with whitespace trimmed
Console.WriteLine("2d) Return all non-whitespace elements with whitespace trimmed:");
result = s2.Split(stringSeparators, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
Show(result);


// Split the string into only two elements, keeping the remainder in the last match
Console.WriteLine("2e) Split into only two elements:");
result = s2.Split(stringSeparators, 2, StringSplitOptions.None);
Show(result);

// Split the string into only two elements with whitespace trimmed, keeping the remainder in the last match
Console.WriteLine("2f) Split into only two elements with whitespace trimmed:");
result = s2.Split(stringSeparators, 2, StringSplitOptions.TrimEntries);
Show(result);

// Split the string into only two non-empty elements, keeping the remainder in the last match
Console.WriteLine("2g) Split into only two non-empty elements:");
result = s2.Split(stringSeparators, 2, StringSplitOptions.RemoveEmptyEntries);
Show(result);

// Split the string into only two non-whitespace elements with whitespace trimmed, keeping the remainder in the last match
Console.WriteLine("2h) Split into only two non-whitespace elements with whitespace trimmed:");
result = s2.Split(stringSeparators, 2, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
Show(result);


// Display the array of separated strings using a local function
void Show(string[] entries)
{
    Console.WriteLine($"The return value contains these {entries.Length} elements:");
    foreach (string entry in entries)
    {
        Console.Write($"<{entry}>");
    }
    Console.Write("\n\n");
}

/*
This example produces the following results:

1) Split a string delimited by characters:

The original string is: ",ONE,, TWO,, , THREE,,".
The delimiter character is: ','.

1a) Return all elements:
The return value contains these 9 elements:
<><ONE><>< TWO><>< >< THREE><><>

1b) Return all elements with whitespace trimmed:
The return value contains these 9 elements:
<><ONE><><TWO><><><THREE><><>

1c) Return all non-empty elements:
The return value contains these 4 elements:
<ONE>< TWO>< >< THREE>

1d) Return all non-whitespace elements with whitespace trimmed:
The return value contains these 3 elements:
<ONE><TWO><THREE>

1e) Split into only two elements:
The return value contains these 2 elements:
<><ONE,, TWO,, , THREE,,>

1f) Split into only two elements with whitespace trimmed:
The return value contains these 2 elements:
<><ONE,, TWO,, , THREE,,>

1g) Split into only two non-empty elements:
The return value contains these 2 elements:
<ONE>< TWO,, , THREE,,>

1h) Split into only two non-whitespace elements with whitespace trimmed:
The return value contains these 2 elements:
<ONE><TWO,, , THREE,,>

2) Split a string delimited by another string:

The original string is: "[stop]ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  ".
The delimiter string is: "[stop]".

2a) Return all elements:
The return value contains these 9 elements:
<><ONE>< ><TWO  ><><  ><THREE><><  >

2b) Return all elements with whitespace trimmed:
The return value contains these 9 elements:
<><ONE><><TWO><><><THREE><><>

2c) Return all non-empty elements:
The return value contains these 6 elements:
<ONE>< ><TWO  ><  ><THREE><  >

2d) Return all non-whitespace elements with whitespace trimmed:
The return value contains these 3 elements:
<ONE><TWO><THREE>

2e) Split into only two elements:
The return value contains these 2 elements:
<><ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  >

2f) Split into only two elements with whitespace trimmed:
The return value contains these 2 elements:
<><ONE[stop] [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]>

2g) Split into only two non-empty elements:
The return value contains these 2 elements:
<ONE>< [stop]TWO  [stop][stop]  [stop]THREE[stop][stop]  >

2h) Split into only two non-whitespace elements with whitespace trimmed:
The return value contains these 2 elements:
<ONE><TWO  [stop][stop]  [stop]THREE[stop][stop]>

*/

備註

方法 String.Split 會傳回指定字串中以指定字元或字串分隔的子字串陣列。 相鄰分隔符號會產生陣列元素，其中包含空字串 ("") 。 列舉的 StringSplitOptions 其中一個欄位會指定是否應該在傳回的陣列中包含包含空字串的專案。

指定要 None 叫用方法的預設行為的 String.Split 欄位，這不會修剪空白字元，以及包含空的子字串。

欄位 TrimEntries 僅適用于 .NET 5 和更新版本。

適用於

另請參閱

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