Base64FormattingOptions 枚举
定义
重要
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指定相关 ToBase64CharArray 和 ToBase64String 方法是否在其输出中插入换行符。
此枚举支持其成员值的按位组合。
public enum class Base64FormattingOptions[System.Flags]
public enum Base64FormattingOptions[<System.Flags>]
type Base64FormattingOptions = Public Enum Base64FormattingOptions- 继承
- 属性
字段
| InsertLineBreaks | 1 | 在字符串表示形式中每隔 76 个字符插入换行符。 |
| None | 0 | 不在字符串表示形式中每隔 76 个字符插入换行符。 |
示例
以下示例使用InsertLineBreaks参数调用Convert.ToBase64String(Byte[], Base64FormattingOptions)该方法，以在编码 100 元素字节数组生成的字符串中插入换行符：
using System;
public class Example
{
public static void Main()
{
// Define a byte array.
var bytes = new byte[100];
int originalTotal = 0;
for (int ctr = 0; ctr <= bytes.GetUpperBound(0); ctr++) {
bytes[ctr] = (byte)(ctr + 1);
originalTotal += bytes[ctr];
}
// Display summary information about the array.
Console.WriteLine("The original byte array:");
Console.WriteLine(" Total elements: {0}", bytes.Length);
Console.WriteLine(" Length of String Representation: {0}",
BitConverter.ToString(bytes).Length);
Console.WriteLine(" Sum of elements: {0:N0}", originalTotal);
Console.WriteLine();
// Convert the array to a base 64 string.
string s = Convert.ToBase64String(bytes,
Base64FormattingOptions.InsertLineBreaks);
Console.WriteLine("The base 64 string:\n {0}\n", s);
// Restore the byte array.
Byte[] newBytes = Convert.FromBase64String(s);
int newTotal = 0;
foreach (var newByte in newBytes)
newTotal += newByte;
// Display summary information about the restored array.
Console.WriteLine(" Total elements: {0}", newBytes.Length);
Console.WriteLine(" Length of String Representation: {0}",
BitConverter.ToString(newBytes).Length);
Console.WriteLine(" Sum of elements: {0:N0}", newTotal);
}
}
// The example displays the following output:
// The original byte array:
// Total elements: 100
// Length of String Representation: 299
// Sum of elements: 5,050
//
// The base 64 string:
// AQIDBAUGBwgJCgsMDQ4PEBESExQVFhcYGRobHB0eHyAhIiMkJSYnKCkqKywtLi8wMTIzNDU2Nzg5
// Ojs8PT4/QEFCQ0RFRkdISUpLTE1OT1BRUlNUVVZXWFlaW1xdXl9gYWJjZA==
//
// Total elements: 100
// Length of String Representation: 299
// Sum of elements: 5,050
open System
// Define a byte array.
let bytes =
[| for i = 0 to 99 do byte (i + 1) |]
let originalTotal = Array.sumBy int bytes
// Display summary information about the array.
printfn "The original byte array:"
printfn $" Total elements: {bytes.Length}"
printfn $" Length of String Representation: {BitConverter.ToString(bytes).Length}"
printfn $" Sum of elements: {originalTotal:N0}"
printfn ""
// Convert the array to a base 64 string.
let s = Convert.ToBase64String(bytes, Base64FormattingOptions.InsertLineBreaks)
printfn $"The base 64 string:\n {s}\n"
// Restore the byte array.
let newBytes = Convert.FromBase64String s
let newTotal = Array.sumBy int newBytes
// Display summary information about the restored array.
printfn $" Total elements: {newBytes.Length}"
printfn $" Length of String Representation: {BitConverter.ToString(newBytes).Length}"
printfn $" Sum of elements: {newTotal:N0}"
// The example displays the following output:
// The original byte array:
// Total elements: 100
// Length of String Representation: 299
// Sum of elements: 5,050
//
// The base 64 string:
// AQIDBAUGBwgJCgsMDQ4PEBESExQVFhcYGRobHB0eHyAhIiMkJSYnKCkqKywtLi8wMTIzNDU2Nzg5
// Ojs8PT4/QEFCQ0RFRkdISUpLTE1OT1BRUlNUVVZXWFlaW1xdXl9gYWJjZA==
//
// Total elements: 100
// Length of String Representation: 299
// Sum of elements: 5,050
Module Example
Public Sub Main()
' Define a byte array.
Dim bytes(99) As Byte
Dim originalTotal As Integer = 0
For ctr As Integer = 0 To bytes.GetUpperBound(0)
bytes(ctr) = CByte(ctr + 1)
originalTotal += bytes(ctr)
Next
' Display summary information about the array.
Console.WriteLine("The original byte array:")
Console.WriteLine(" Total elements: {0}", bytes.Length)
Console.WriteLine(" Length of String Representation: {0}",
BitConverter.ToString(bytes).Length)
Console.WriteLine(" Sum of elements: {0:N0}", originalTotal)
Console.WriteLine()
' Convert the array to a base 64 string.
Dim s As String = Convert.ToBase64String(bytes,
Base64FormattingOptions.InsertLineBreaks)
Console.WriteLine("The base 64 string:{1} {0}{1}",
s, vbCrLf)
' Restore the byte array.
Dim newBytes() As Byte = Convert.FromBase64String(s)
Dim newTotal As Integer = 0
For Each newByte In newBytes
newTotal += newByte
Next
' Display summary information about the restored array.
Console.WriteLine(" Total elements: {0}", newBytes.Length)
Console.WriteLine(" Length of String Representation: {0}",
BitConverter.ToString(newBytes).Length)
Console.WriteLine(" Sum of elements: {0:N0}", newTotal)
End Sub
End Module
' The example displays the following output:
' The original byte array:
' Total elements: 100
' Length of String Representation: 299
' Sum of elements: 5,050
'
' The base 64 string:
' AQIDBAUGBwgJCgsMDQ4PEBESExQVFhcYGRobHB0eHyAhIiMkJSYnKCkqKywtLi8wMTIzNDU2Nzg5
' Ojs8PT4/QEFCQ0RFRkdISUpLTE1OT1BRUlNUVVZXWFlaW1xdXl9gYWJjZA==
'
' Total elements: 100
' Length of String Representation: 299
' Sum of elements: 5,050
如示例中的输出所示， Convert.FromBase64String 成功还原原始字节数组;换行符在转换期间将被忽略。
注解
和Convert.ToBase64CharArrayConvert.ToBase64String方法将 8 位无符号整数数组的值转换为包含 base 64 位数字的等效字符串表示形式。 字符串表示形式可以包含一个或多个换行符，其中换行符定义为回车符， (U+000D) 后跟换行符 (U+000A) 。 由于换行符在 base-64 编码中被视为空白字符，因此在将 base-64 编码的字符串转换回字节数组时将被忽略。 向控件或设备（如控制台窗口）显示编码字符串时，换行符很简单。
值None``InsertLineBreaks相互排斥。 因此，尽管 Base64FormattingOptions 枚举用 FlagsAttribute 属性标记，但执行这两个值的按位组合并不有意义。