ASP.NET：URI 处理

Question

我正在编写一个方法，假设给定 1 和 hello 应该返回 http://something.com/?something=1&hello=en。

我可以很容易地将其组合在一起，但是 ASP.NET 3.5 为构建 URI 提供了什么抽象功能？我想要这样的东西：

URI uri = new URI("~/Hello.aspx"); // E.g. ResolveUrl is used here
uri.QueryString.Set("something", "1");
uri.QueryString.Set("hello", "en");
return uri.ToString(); // /Hello.aspx?something=1&hello=en

我发现 Uri 类听起来非常相关，但我找不到任何真正执行上述操作的东西。有什么想法吗？

（就其价值而言，参数的顺序对我来说并不重要。）

Answer 1

编辑以纠正大量错误的代码

基于这个答案对于类似的问题，您可以轻松地执行以下操作：

UriBuilder ub = new UriBuilder();

// You might want to take more care here, and set the host, scheme and port too
ub.Path = ResolveUrl("~/hello.aspx"); // Assumes we're on a page or control.

// Using var gets around internal nature of HttpValueCollection
var coll = HttpUtility.ParseQueryString(string.Empty);

coll["something"] = "1";
coll["hello"] = "en";

ub.Query = coll.ToString();
return ub.ToString();
// This returned the following on the VS development server:
// http://localhost/Hello.aspx?something=1&hello=en

这也将对集合进行urlencode，因此：

coll["Something"] = "1";
coll["hello"] = "en&that";

将输出：

Something=1&hello=en%26that 

Answer 2

到目前为止我对这里一无所知。所以每个人都有自己的实现。

示例来自 LinqToTwitter。

    internal static string BuildQueryString(IEnumerable<KeyValuePair<string, string>> parameters)
    {
        if (parameters == null)
        {
            throw new ArgumentNullException("parameters");
        }

        StringBuilder builder = new StringBuilder();
        foreach (var pair in parameters.Where(p => !string.IsNullOrEmpty(p.Value)))
        {
            if (builder.Length > 0)
            {
                builder.Append("&");
            }

            builder.Append(Uri.EscapeDataString(pair.Key));
            builder.Append("=");
            builder.Append(Uri.EscapeDataString(pair.Value));
        }

        return builder.ToString();
    }

更新：

您还可以创建扩展方法：

public static UriBuilder AddArgument(this UriBuilder builder, string key, string value)
{
 #region Contract

 Contract.Requires(builder != null);
 Contract.Requires(key != null);
 Contract.Requires(value != null);

 #endregion

 var query = builder.Query;

 if (query.Length > 0)
 {
      query = query.Substring(1) + "&";
 } 

 query += Uri.EscapeDataString(key) + "="
      + Uri.EscapeDataString(value);

 builder.Query = query;

 return builder;
}

和用法：

var b = new UriBuilder();
b.AddArgument("test", "test");

请注意，这里的所有内容都未经测试。

Answer 3

只是合并答案=>

public static class UriBuilderExtensions
{
    public static void AddQueryArgument(this UriBuilder b, string key, string value)
    {
        key = Uri.EscapeDataString(key);
        value = Uri.EscapeDataString(value);

        var x = HttpUtility.ParseQueryString(b.Query);
        if (x.AllKeys.Contains(key)) throw new ArgumentNullException
                ("Key '{0}' already exists!".FormatWith(key));
        x.Add(key, value);
        b.Query = x.ToString();
    }

    public static void EditQueryArgument(this UriBuilder b, string key, string value)
    {
        key = Uri.EscapeDataString(key);
        value = Uri.EscapeDataString(value);

        var x = HttpUtility.ParseQueryString(b.Query);
        if (x.AllKeys.Contains(key))
            x[key] = value;
        else throw new ArgumentNullException
                ("Key '{0}' does not exists!".FormatWith(key));
        b.Query = x.ToString();
    }

    public static void AddOrEditQueryArgument(this UriBuilder b, string key, string value)
    {
        key = Uri.EscapeDataString(key);
        value = Uri.EscapeDataString(value);

        var x = HttpUtility.ParseQueryString(b.Query);
        if (x.AllKeys.Contains(key))
            x[key] = value;
        else
            x.Add(key, value);
        b.Query = x.ToString();
    }

    public static void DeleteQueryArgument(this UriBuilder b, string key)
    {
        key = Uri.EscapeDataString(key);
        var x = HttpUtility.ParseQueryString(b.Query);
        if (x.AllKeys.Contains(key))
            x.Remove(key);
        b.Query = x.ToString();
    }
}

半成品代码。但应该工作得足够好。

Answer 4

还有 UriBuilder 类

Answer 5

这可能会吸引你——最近在工作中我正在寻找一种“输入”常用的 URL 查询字符串变量的方法，因此开发了这个接口：

   'Represent a named parameter that is passed from page-to-page via a range of methods- query strings, HTTP contexts, cookies, session, etc.
Public Interface INamedParam

    'A key that uniquely identfies this parameter in any HTTP value collection (query string, context, session, etc.)
    ReadOnly Property Key() As String

    'The default value of the paramter.
    ReadOnly Property DefaultValue() As Object

End Interface

然后你可以实现这个接口来描述一个查询字符串参数，这样的实现您的“Hello”参数可能如下所示：

Public Class HelloParam
    Implements INamedParam

    Public ReadOnly Property DefaultValue() As Object Implements INamedParam.DefaultValue
        Get
            Return "0"
        End Get
    End Property

    Public ReadOnly Property Key() As String Implements INamedParam.Key
        Get
            Return "hello"
        End Get
    End Property
End Class

我开发了一个小型（非常非常基本）类来帮助使用这些强类型参数构建 URL：

Public Class ParametrizedHttpUrlBuilder

    Private _RelativePath As String
    Private _QueryString As String

    Sub New(ByVal relativePath As String)
        _RelativePath = relativePath
        _QueryString = ""
    End Sub

    Public Sub AddQueryParameterValue(ByVal param As INamedParam, ByVal value As Object)
        Dim sb As New Text.StringBuilder(30)
        If _QueryString.Length > 0 Then
            sb.Append("&")
        End If
        sb.AppendFormat("{0}={1}", param.Key, value.ToString())
        _QueryString &= sb.ToString()
    End Sub

    Public Property RelativePath() As String
        Get
            Return _RelativePath
        End Get
        Set(ByVal value As String)
            If value Is Nothing Then
                _RelativePath = ""
            End If
            _RelativePath = value
        End Set
    End Property

    Public ReadOnly Property Query() As String
        Get
            Return _QueryString
        End Get
    End Property

    Public ReadOnly Property PathAndQuery() As String
        Get
            Return _RelativePath & "?" & _QueryString
        End Get
    End Property

End Class

Answer 6

这是我的版本（需要在 Select 上调用 .NET4 或 ToArray() ）

var items = new Dictionary<string,string> { { "Name", "Will" }, { "Age", "99" }};

String query = String.Join("&", items.Select(i => String.Concat(i.Key, "=", i.Value)));

我认为使用 Dictionary 可能意味着可以对项目进行重新排序，但这实际上似乎并没有在此处的实验中发生 - 不确定那是什么意思。