C# Char.IsControl(String, Int32)用法及代码示例

此方法用于指示是否将指定字符串中指定位置的字符归类为控制字符。

用法:

public static bool IsControl (string s, int index);

参数：

s：这是字符串。
index：它是s中的字符位置。

返回值：如果s中位置索引处的字符是控制字符，则此方法返回true，否则返回false。

异常：

ArgumentNullException：如果s为null。
ArgumentOutOfRangeException：如果索引小于零或大于s中的最后一个位置。

注意：控制字符是格式化字符和其他非打印字符，例如ACK, BEL, CR, FF, LF, and VT。

以下示例程序旨在说明Char.IsControl(String，Int32)方法的用法：

范例1：

// C# program to demonstrate the 
// Char.IsControl(String, Int32)  
// Method 
using System; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
  
        try { 
  
            // calling check() Method 
            check("1234", 3); 
            check("Tsunami", 3); 
            check("psyc0lo", 4); 
            check("a" + Environment.NewLine + "b", 1); 
        } 
  
        catch (ArgumentNullException e) { 
  
            Console.Write("Exception Thrown:"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
  
        catch (ArgumentOutOfRangeException e) { 
  
            Console.Write("Exception Thrown:"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
  
    // Defining check() method 
    public static void check(string s, int i) 
    { 
  
        // checking condition 
        // using GetNumericValue() Method 
        bool val = Char.IsControl(s, i); 
  
        // checking 
        if (val) 
            Console.WriteLine("Control character \\U{0} "+ 
                                 "found in position {1}.",  
                 Convert.ToInt32(s[i]).ToString("X4"), i); 
  
        else
            Console.WriteLine("String '{0}' does't contain control "+ 
                                      "character at index {1}", s, i); 
    } 
}

输出：

String '1234' does't contain control character at index 3
String 'Tsunami' does't contain control character at index 3
String 'psyc0lo' does't contain control character at index 4
Control character \U000A found in position 1.

范例2：对于ArgumentNullException

// C# program to demonstrate the 
// Char.IsControl(String, Int32)  
// Method 
using System; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        try { 
  
            // calling check() Method 
            check("1234", 3); 
            check("psyc0lo", 4); 
            check("a" + Environment.NewLine + "b", 1); 
            Console.WriteLine(""); 
            Console.WriteLine("s is null"); 
            check(null, 4); 
        } 
        catch (ArgumentNullException e) { 
  
            Console.Write("Exception Thrown:"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
        catch (ArgumentOutOfRangeException e) { 
  
            Console.Write("Exception Thrown:"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
  
    // Defining check() method 
    public static void check(string s, int i) 
    { 
        // checking condition 
        // using GetNumericValue() Method 
        bool val = Char.IsControl(s, i); 
  
        // checking 
        if (val) 
            Console.WriteLine("Control character \\U{0} found"+ 
                                           " in position {1}.", 
                       Convert.ToInt32(s[i]).ToString("X4"), i); 
        else
            Console.WriteLine("String '{0}' does't contain "+ 
                     "control character at index {1}", s, i); 
    } 
}

输出：

String '1234' does't contain control character at index 3
String 'psyc0lo' does't contain control character at index 4
Control character \U000A found in position 1.

s is null
Exception Thrown:System.ArgumentNullException

范例3：对于ArgumentOutOfRangeException

// C# program to demonstrate the 
// Char.IsControl(String, Int32)  
// Method 
using System; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        try { 
  
            // calling check() Method 
            check("1234", 3); 
            check("psyc0lo", 4); 
            check("a" + Environment.NewLine + "b", 1); 
  
            Console.WriteLine(""); 
            Console.WriteLine("index is less than zero"); 
  
            check("null", -1); 
        } 
        catch (ArgumentNullException e) { 
  
            Console.Write("Exception Thrown:"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
        catch (ArgumentOutOfRangeException e) { 
  
            Console.Write("Exception Thrown:"); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
  
    // Defining check() method 
    public static void check(string s, int i) 
    { 
        // checking condition 
        // using GetNumericValue() Method 
        bool val = Char.IsControl(s, i); 
  
        // checking 
        if (val) 
            Console.WriteLine("Control character \\U{0} found "+ 
                                              "in position {1}.", 
                        Convert.ToInt32(s[i]).ToString("X4"), i); 
        else
            Console.WriteLine("String '{0}' does't contain control"+ 
                                   " character at index {1}", s, i); 
    } 
}

输出：

String '1234' does't contain control character at index 3
String 'psyc0lo' does't contain control character at index 4
Control character \U000A found in position 1.

index is less than zero
Exception Thrown:System.ArgumentOutOfRangeException

参考：

https://docs.microsoft.com/en-us/dotnet/api/system.char.iscontrol?view=netframework-4.7.2#System_Char_IsControl_System_String_System_Int32_

相关用法

注：本文由纯净天空筛选整理自RohitPrasad3大神的英文原创作品 C# | Char.IsControl(String, Int32) Method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。