HttpWebRequest.ContentLength 屬性

定義

命名空間:

System.Net

組件:

System.Net.Requests.dll

來源:

HttpWebRequest.cs

取得或設定 HTTP 標頭 Content-length。

public:
 virtual property long ContentLength { long get(); void set(long value); };

public override long ContentLength { get; set; }

member this.ContentLength : int64 with get, set

Public Overrides Property ContentLength As Long

屬性值

Int64

要傳送至因特網資源的數據位元組數目。 默認值為 -1，表示尚未設定 屬性，而且沒有要傳送的要求數據。

例外狀況

InvalidOperationException

要求已透過呼叫 GetRequestStream()、BeginGetRequestStream(AsyncCallback, Object)、GetResponse()或 BeginGetResponse(AsyncCallback, Object) 方法來啟動。

ArgumentOutOfRangeException

新的 ContentLength 值小於 0。

範例

下列程式代碼範例會將 ContentLength 屬性設定為所張貼字串的長度。

// Set the 'Method' property of the 'Webrequest' to 'POST'.
myHttpWebRequest->Method = "POST";
Console::WriteLine( "\nPlease enter the data to be posted to the (http://www.contoso.com/codesnippets/next.asp) Uri :" );

// Create a new String* Object* to POST data to the Url.
String^ inputData = Console::ReadLine();

String^ postData = String::Concat( "firstone= ", inputData );
ASCIIEncoding^ encoding = gcnew ASCIIEncoding;
array<Byte>^ byte1 = encoding->GetBytes( postData );

// Set the content type of the data being posted.
myHttpWebRequest->ContentType = "application/x-www-form-urlencoded";

// Set the content length of the String* being posted.
myHttpWebRequest->ContentLength = byte1->Length;

Stream^ newStream = myHttpWebRequest->GetRequestStream();

newStream->Write( byte1, 0, byte1->Length );
Console::WriteLine( "The value of 'ContentLength' property after sending the data is {0}", myHttpWebRequest->ContentLength );

// Close the Stream Object*.
newStream->Close();

// Set the 'Method' property of the 'Webrequest' to 'POST'.
myHttpWebRequest.Method = "POST";
Console.WriteLine ("\nPlease enter the data to be posted to the (http://www.contoso.com/codesnippets/next.asp) Uri :");

// Create a new string object to POST data to the Url.
string inputData = Console.ReadLine ();


string postData = "firstone=" + inputData;
ASCIIEncoding encoding = new ASCIIEncoding ();
byte[] byte1 = encoding.GetBytes (postData);

// Set the content type of the data being posted.
myHttpWebRequest.ContentType = "application/x-www-form-urlencoded";

// Set the content length of the string being posted.
myHttpWebRequest.ContentLength = byte1.Length;

Stream newStream = myHttpWebRequest.GetRequestStream ();

newStream.Write (byte1, 0, byte1.Length);
Console.WriteLine ("The value of 'ContentLength' property after sending the data is {0}", myHttpWebRequest.ContentLength);

// Close the Stream object.
newStream.Close ();

' Set the 'Method' property of the 'Webrequest' to 'POST'.
myHttpWebRequest.Method = "POST"

Console.WriteLine(ControlChars.Cr + "Please enter the data to be posted to the (http://www.contoso.com/codesnippets/next.asp) Uri :")
' Create a new string object to POST data to the Url.
Dim inputData As String = Console.ReadLine()
Dim postData As String = "firstone" + ChrW(61) + inputData
Dim encoding As New ASCIIEncoding()
Dim byte1 As Byte() = encoding.GetBytes(postData)
' Set the content type of the data being posted.
myHttpWebRequest.ContentType = "application/x-www-form-urlencoded"
' Set the content length of the string being posted.
myHttpWebRequest.ContentLength = byte1.Length
Dim newStream As Stream = myHttpWebRequest.GetRequestStream()
newStream.Write(byte1, 0, byte1.Length)
Console.WriteLine("The value of 'ContentLength' property after sending the data is {0}", myHttpWebRequest.ContentLength)
newStream.Close()

備註

謹慎

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。

ContentLength 屬性包含要以要求傳送為 Content-length HTTP 標頭的值。

ContentLength 屬性中 -1 以外的任何值都表示要求會上傳數據，而且只允許在 Method 屬性中設定上傳數據的方法。

將 ContentLength 屬性設定為值之後，必須透過呼叫 GetRequestStream 方法或 BeginGetRequestStream 和 EndGetRequestStream 方法傳回的要求數據流寫入該位元組數目。

注意

此屬性的值會儲存在 WebHeaderCollection中。 如果已設定 WebHeaderCollection，屬性值就會遺失。