C＃| Convert.ToByte(String，IFormatProvider)方法

此方法用于使用指定的区域性特定格式信息将数字的指定字符串表示形式转换为等效的8位无符号整数。

句法：

public static byte ToByte (string value, IFormatProvider provider);

参数：

• value：它是一个包含要转换的数字的字符串。
• provider：提供者：提供特定于区域性的格式信息的对象。

返回值：该方法返回一个与value等效的8位无符号整数，如果value为null ，则返回零。

例外情况：

• FormatException：如果该值不包含一个可选的符号，后跟一个数字序列(0到9)。
• OverflowException：如果该值表示一个小于MinValue或大于MaxValue的数字。

下面的程序说明了Convert.ToByte(String，IFormatProvider)方法的用法：

范例1：

// C# program to demonstrate the
// Convert.ToByte() Method
using System;
using System.Globalization;
class GFG {
  
// Main Method
public static void Main()
{
    try {
          
        // creating object of CultureInfo
        CultureInfo cultures = new CultureInfo("en-US");
  
        // declaring and intializing String array
        string[] values = { "234", "+234", "240", 
                           "255", "140", "120" };
  
        // calling get() Method
        Console.WriteLine("Converted bool value "+
                        "of specified strings: ");
                          
        for (int j = 0; j < values.Length; j++) {
              
            get(values[j], cultures);
        }
    }
      
    catch (FormatException e) {
          
        Console.WriteLine("\n");
        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }
    catch (OverflowException e) {
          
        Console.WriteLine("\n");
        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }
}
  
// Defining get() method
public static void get(string s, CultureInfo cultures)
{
  
    // converting string to specified bool
    byte val = Convert.ToByte(s, cultures);
  
    // display the converted string
    Console.Write(" {0}, ", val);
}
}

输出：

Converted bool value of specified strings: 
 234,  234,  240,  255,  140,  120,

示例2：对于FormatException

// C# program to demonstrate the
// Convert.ToByte() Method
using System;
using System.Globalization;
class GFG {
  
// Main Method
public static void Main()
{
    try {
          
        // creating object of CultureInfo
        CultureInfo cultures = new CultureInfo("en-US");
  
        // declaring and intializing String array
        string[] values = {"234", "+234", "240",
                             "255", "140", "A"};
  
        // calling get() Method
        Console.WriteLine("]n Converted bool value "+
                           "of specified strings: ");
                             
        for (int j = 0; j < values.Length; j++) {
            get(values[j], cultures);
        }
    }
      
    catch (FormatException e) {
          
        Console.WriteLine("\n\nvalue consist invalid format");
        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }
      
    catch (OverflowException e) {
          
        Console.WriteLine("\n value represents a "+
              "number that is less than MinValue");
                
        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }
}
  
// Defining get() method
public static void get(string s,
           CultureInfo cultures)
{
  
    // converting string to specified bool
    byte val = Convert.ToByte(s, cultures);
  
    // display the converted string
    Console.Write(" {0}, ", val);
}
}

输出：

]n Converted bool value of specified strings: 
 234,  234,  240,  255,  140, 

value consist invalid format
Exception Thrown: System.FormatException

示例3：对于OverflowException

// C# program to demonstrate the
// Convert.ToByte() Method
using System;
using System.Globalization;
  
class GFG {
  
// Main Method
public static void Main()
{
    try {
          
        // creating object of CultureInfo
        CultureInfo cultures = new CultureInfo("en-US");
  
        // declaring and intializing String array
        string[] values = {"234", "+234", "240",
                           "255", "140", "-1" };
  
        // calling get() Method
        Console.WriteLine("]n Converted bool value"+
                         " of specified strings: ");
                           
        for (int j = 0; j < values.Length; j++) {
            get(values[j], cultures);
        }
    }
      
    catch (FormatException e) {
          
        Console.WriteLine("\n\nvalue consist invalid format");
        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }
      
    catch (OverflowException e) {
          
        Console.WriteLine("\n\nvalue represents a number"+
                           " that is less than MinValue");
        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }
}
  
// Defining get() method
public static void get(string s, CultureInfo cultures)
{
  
    // converting string to specified bool
    byte val = Convert.ToByte(s, cultures);
  
    // display the converted string
    Console.Write(" {0}, ", val);
}
}

输出：

]n Converted bool value of specified strings: 
 234,  234,  240,  255,  140, 

value represents a number that is less than MinValue
Exception Thrown: System.OverflowException

参考：

• https://docs.microsoft.com/zh-cn/dotnet/api/system.convert.tobyte?view=netframework-4.7.2#System_Convert_ToByte_System_String_System_IFormatProvider_