WebClient.QueryString 屬性
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
取得或設定與要求相關聯的查詢名稱/值組集合。
public:
property System::Collections::Specialized::NameValueCollection ^ QueryString { System::Collections::Specialized::NameValueCollection ^ get(); void set(System::Collections::Specialized::NameValueCollection ^ value); };C#
public System.Collections.Specialized.NameValueCollection QueryString { get; set; }member this.QueryString : System.Collections.Specialized.NameValueCollection with get, setPublic Property QueryString As NameValueCollectionNameValueCollection，其中包含與要求相關聯的查詢名稱/值組。 如果沒有配對與要求相關聯，則值會是空的 NameValueCollection。
下列程式代碼範例會從命令行取得使用者輸入，並建置指派給 QueryString 屬性的 NameValueCollection。 然後，它會將伺服器的回應下載到本機檔案。
String^ uriString = "http://www.contoso.com/search";
// Create a new WebClient instance.
WebClient^ myWebClient = gcnew WebClient;
// Create a new NameValueCollection instance to hold the QueryString parameters and values.
NameValueCollection^ myQueryStringCollection = gcnew NameValueCollection;
Console::Write( "Enter the word(s), separated by space character to search for in {0}: ", uriString );
// Read user input phrase to search for at uriString.
String^ searchPhrase = Console::ReadLine();
if ( searchPhrase->Length > 1 )
{
// Assign the user-defined search phrase.
myQueryStringCollection->Add( "q", searchPhrase );
}
else
{
// If error, default to search for 'Microsoft'.
myQueryStringCollection->Add( "q", "Microsoft" );
}
// Assign auxilliary parameters required for the search.
Console::WriteLine( "Searching {0} .......", uriString );
// Attach QueryString to the WebClient.
myWebClient->QueryString = myQueryStringCollection;
// Download the search results Web page into 'searchresult.htm' for inspection.
myWebClient->DownloadFile( uriString, "searchresult.htm" );
Console::WriteLine( "\nDownload of {0} was successful. Please see 'searchresult.htm' for results.", uriString );
C#
string uriString = "http://www.contoso.com/search";
// Create a new WebClient instance.
WebClient myWebClient = new WebClient();
// Create a new NameValueCollection instance to hold the QueryString parameters and values.
NameValueCollection myQueryStringCollection = new NameValueCollection();
Console.Write("Enter the word(s), separated by space character to search for in " + uriString + ": ");
// Read user input phrase to search for at uriString.
string searchPhrase = Console.ReadLine();
if (searchPhrase.Length > 1)
// Assign the user-defined search phrase.
myQueryStringCollection.Add("q",searchPhrase);
else
// If error, default to search for 'Microsoft'.
myQueryStringCollection.Add("q","Microsoft");
// Assign auxilliary parameters required for the search.
Console.WriteLine("Searching " + uriString + " .......");
// Attach QueryString to the WebClient.
myWebClient.QueryString = myQueryStringCollection;
// Download the search results Web page into 'searchresult.htm' for inspection.
myWebClient.DownloadFile (uriString, "searchresult.htm");
Console.WriteLine("\nDownload of " + uriString + " was successful. Please see 'searchresult.htm' for results.");
Dim uriString As String = "http://www.contoso.com/search"
' Create a new WebClient instance.
Dim myWebClient As New WebClient()
' Create a new NameValueCollection instance to hold the QueryString parameters and values.
Dim myQueryStringCollection As New NameValueCollection()
Console.Write(("Enter the word(s), separated by space characters, to search for in " + uriString + ": "))
' Read user input phrase to search in uriString.
Dim searchPhrase As String = Console.ReadLine()
If searchPhrase.Length > 1 Then
'Assign the user-defined search phrase.
myQueryStringCollection.Add("q", searchPhrase)
' If error, default to search 'Microsoft'.
Else
myQueryStringCollection.Add("q", "Microsoft")
End If
' Assign auxilliary parameters required for the search.
Console.WriteLine(("Searching " + uriString + " ......."))
' Attach QueryString to the WebClient.
myWebClient.QueryString = myQueryStringCollection
' Download the search results Web page into 'searchresult.htm' for inspection.
myWebClient.DownloadFile(uriString, "searchresult.htm")
Console.WriteLine((ControlChars.Cr + "Download of " + uriString + " was successful. Please see 'searchresult.htm' for results."))
警告
WebRequest、HttpWebRequest、ServicePoint和 WebClient 已經過時，您不應該將它們用於新的開發。 請改用 HttpClient。
QueryString 屬性包含 NameValueCollection 實例，其中包含附加至 URI 做為查詢字串的名稱/值組。 QueryString 屬性的內容前面加上問號（？），名稱/值組會以連字元分隔（&）。
| 產品 | 版本 |
|---|---|
| .NET | Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10 |
| .NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
| .NET Standard | 2.0, 2.1 |
