我正在把VB转换成c#。这条语句的语法有问题:

if ((searchResult.Properties["user"].Count > 0))
{
    profile.User = System.Text.Encoding.UTF8.GetString(searchResult.Properties["user"][0]);
}

然后我看到以下错误:

参数1:不能将'object'转换为'byte[]' 匹配的最佳重载方法 'System.Text.Encoding.GetString(byte[])'有一些无效的参数

我试图根据这篇文章修复代码,但仍然没有成功

string User = Encoding.UTF8.GetString("user", 0);

有什么建议吗?


当前回答

有人知道为什么不这样做吗?

mystring.Select(Convert.ToByte).ToArray()

其他回答

var result = System.Text.Encoding.Unicode.GetBytes(text);

您可以使用MemoryMarshal API来执行非常快速和有效的转换。字符串将隐式强制转换为ReadOnlySpan<字节>,作为MemoryMarshal。强制转换接受Span<byte>或ReadOnlySpan<byte>作为输入参数。

public static class StringExtensions
{
    public static byte[] ToByteArray(this string s) => s.ToByteSpan().ToArray(); //  heap allocation, use only when you cannot operate on spans
    public static ReadOnlySpan<byte> ToByteSpan(this string s) => MemoryMarshal.Cast<char, byte>(s);
}

下面的基准测试显示了差异:

Input: "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s,"

|                       Method |       Mean |     Error |    StdDev |  Gen 0 | Gen 1 | Gen 2 | Allocated |
|----------------------------- |-----------:|----------:|----------:|-------:|------:|------:|----------:|
| UsingEncodingUnicodeGetBytes | 160.042 ns | 3.2864 ns | 6.4099 ns | 0.0780 |     - |     - |     328 B |
| UsingMemoryMarshalAndToArray |  31.977 ns | 0.7177 ns | 1.5753 ns | 0.0781 |     - |     - |     328 B |
|           UsingMemoryMarshal |   1.027 ns | 0.0565 ns | 0.1630 ns |      - |     - |     - |         - |

使用这个

byte[] myByte= System.Text.ASCIIEncoding.Default.GetBytes(myString);

这个工作为我,之后我可以转换把我的照片在bytea字段在我的数据库。

using (MemoryStream s = new MemoryStream(DirEntry.Properties["thumbnailphoto"].Value as byte[]))
{
    return s.ToArray();
}

如果的结果,'searchResult.;属性["user"][0]',是一个字符串:

if ( ( searchResult.Properties [ "user" ].Count > 0 ) ) {

   profile.User = System.Text.Encoding.UTF8.GetString ( searchResult.Properties [ "user" ] [ 0 ].ToCharArray ().Select ( character => ( byte ) character ).ToArray () );

}

关键是将字符串转换为字节[]可以使用LINQ完成:

.ToCharArray ().Select ( character => ( byte ) character ).ToArray () )

反过来说:

.Select ( character => ( char ) character ).ToArray () )