HttpWebRequest.ContentLength 属性

项目
08/17/2007

获取或设置 Content-lengthHTTP 标头。

**命名空间:**System.Net
**程序集:**System（在 system.dll 中）

语法

声明
Public Overrides Property ContentLength As Long
用法
Dim instance As HttpWebRequest
Dim value As Long

value = instance.ContentLength

instance.ContentLength = value

public override long ContentLength { get; set; }

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

/** @property */
public long get_ContentLength ()

/** @property */
public void set_ContentLength (long value)

public override function get ContentLength () : long

public override function set ContentLength (value : long)

属性值

要发送到 Internet 资源的数据的字节数。默认值为 -1，该值指示尚未设置该属性，并且没有要发送的请求数据。

异常

异常类型	条件
InvalidOperationException	已通过调用 GetRequestStream、BeginGetRequestStream、GetResponse 或 BeginGetResponse 方法启动了该请求。
ArgumentOutOfRangeException	新的 ContentLength 值小于 0。

备注

ContentLength 属性包含要作为请求发送的 Content-lengthHTTP 标头值。

ContentLength 属性中除 -1 以外的任何值都指示请求将上载数据并且只允许在 Method 属性中设置上载数据的方法。

ContentLength 属性被设置为某个值之后，该字节数就必须写入通过调用 GetRequestStream 方法或同时调用 BeginGetRequestStream 和 EndGetRequestStream 方法返回的请求流。

提示

此属性的值存储在 WebHeaderCollection 中。如果设置了 WebHeaderCollection，则该属性值将丢失。

示例

下面的代码示例将 ContentLength 属性设置为正在发送的字符串的长度。

' 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 (https://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()

// Set the 'Method' property of the 'Webrequest' to 'POST'.
myHttpWebRequest.Method = "POST";
Console.WriteLine ("\nPlease enter the data to be posted to the (https://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( "\nPlease enter the data to be posted to the (https://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.set_Method("POST");
Console.WriteLine("\nPlease enter the data to be posted to the "
    + "(https://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();
ubyte byte1[] = encoding.GetBytes(postData);

// Set the content type of the data being posted.
myHttpWebRequest.set_ContentType("application/x-www-form-"
    +"urlencoded");
// Set the content length of the string being posted.
myHttpWebRequest.set_ContentLength(postData.length());

Stream newStream = myHttpWebRequest.GetRequestStream();

newStream.Write(byte1, 0, byte1.length);
Console.WriteLine("The value of 'ContentLength' property after"
    + " sending the data is {0}", 
    System.Convert.ToString(myHttpWebRequest.get_ContentLength()));
// Close the Stream object.
newStream.Close();

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

HttpWebRequest.ContentLength 属性

语法

属性值

异常

备注

示例

平台

版本信息

.NET Framework

.NET Compact Framework

请参见

参考

其他资源