vb.net 上传图像多部分表单 HTTPWebRequest - 将图像数据转换为字符串？
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Uploading Image MultiPart Form HTTPWebRequest - Getting Image Data To String?
提问by Chris
I am trying to upload a multi-part form with HTTPWebRequest & all is ok until I added an image to upload, mainly I am trying to do exactly the same request as a browser makes which looks like this:
我正在尝试使用 HTTPWebRequest 上传多部分表单，一切正常，直到我添加了要上传的图像，主要是我尝试执行与浏览器完全相同的请求，如下所示：
-----------------------------41184676334
Content-Disposition: form-data; name="file"; filename="guitar tape.jpg"
Content-Type: image/jpeg
IMAGEDATAHERE
-----------------------------41184676334
Content-Disposition: form-data; name="save"
save
-----------------------------41184676334--
I am lost on how to format / read the image to set it into the request that I am making below:
我不知道如何格式化/读取图像以将其设置为我在下面提出的请求：
Dim boundary As String = "-----------------------------" & DateTime.Now.Ticks.ToString("x")
Dim req As HttpWebRequest = DirectCast(WebRequest.Create("http://www.mysite.com/upload.php"), HttpWebRequest)
req.Method = "POST"
req.ContentType = "multipart/form-data; boundary=" & "---------------------------" & DateTime.Now.Ticks.ToString("x")
req.KeepAlive = False
Dim builder As New StringBuilder()
builder.Append(boundary & vbCrLf & "Content-Disposition: form-data; name=""variable1""" & vbCrLf & vbCrLf & "1" & vbCrLf)
builder.Append(boundary & vbCrLf & "Content-Disposition: form-data; name=""file""; filename=""" & FileName & """" & vbCrLf)
builder.Append("Content-Type: application/octet-stream")
builder.Append(vbCrLf & vbCrLf)
' Add Photo Here
If UpdateImage = True Then
' Load Image
Dim ImageData As System.Drawing.Image
Dim fs As New System.IO.FileStream(ImagePath, System.IO.FileMode.Open)
ImageData = Image.FromStream(fs)
fs.Close()
' Add Image To Header
builder.Append(ImageData)
builder.Append(vbCrLf)
Else
builder.Append(vbCrLf)
End If
builder.Append(boundary & vbCrLf & "Content-Disposition: form-data; name=""save""" & vbCrLf & vbCrLf & "save")
' Footer Bytes
Dim close As Byte() = Encoding.UTF8.GetBytes("--")
Dim postHeader As String = builder.ToString()
Dim postHeaderBytes As Byte() = Encoding.UTF8.GetBytes(postHeader)
Dim boundaryBytes As Byte() = Encoding.ASCII.GetBytes(vbCrLf & boundary & "--" & vbCrLf)
Dim length As Long = postHeaderBytes.Length + boundaryBytes.Length
req.ContentLength = length
Dim requestStream As Stream = req.GetRequestStream()
Dim fulllength As Integer = postHeaderBytes.Length + boundaryBytes.Length
' Write out our post header
requestStream.Write(postHeaderBytes, 0, postHeaderBytes.Length)
' Write out the trailing boundary
requestStream.Write(boundaryBytes, 0, boundaryBytes.Length)
Dim responce As WebResponse
responce = req.GetResponse()
requestStream.Close()
Dim s As Stream = responce.GetResponseStream()
Dim sr As New StreamReader(s)
Dim Content As String = sr.ReadToEnd()
At the moment it is simply posting "System.Drawing.Bitmap" as the image data but I am not sure how to get the same raw data for the image that looks like this:
目前它只是将“System.Drawing.Bitmap”作为图像数据发布，但我不确定如何为看起来像这样的图像获取相同的原始数据：
J??Y¨e?Ln????/?§úD5y?C÷Cy>?'t;fm—=?w:?/E±?ù?$á@%Pc>× ?gw.2Ab“:?óù:?ˉìh6àZ§ó?g￡?húD6¨?^ú2?`?¨L?Y???CX#I“èì?j|L??'|￥?Eb??Q–¤ú,?3\UzL????oj4??±'u?c?#?o?`?F>·o—??????????yo*i°?èV??Q?”?[.??m?E?ì|eNCh?ù
é§?é$m???"?ìN?(Vìmp?F1Xè88?aüμ…d?Xμ?ü#???v‘o?F?§Y?b
Any ideas on how I could do this or would I need to change my methods?
关于我如何做到这一点的任何想法，或者我是否需要改变我的方法？
回答by urlreader
builder.Append(ImageData)
is not correct. you need read the image as byte, then add the byte[] to the multipart post.
是不正确的。您需要将图像读取为字节，然后将字节 [] 添加到多部分帖子中。
see details at Using HttpWebRequest to POST data/upload image using multipart/form-data
请参阅使用 HttpWebRequest 使用 multipart/form-data POST 数据/上传图像中的详细信息
and make sure use a http sniffer (i.e. fiddler) to see what it is actually sending.
并确保使用 http 嗅探器（即提琴手）查看它实际发送的内容。
first, load image into byte array, then convert it to base64:
首先，将图像加载到字节数组中，然后将其转换为 base64：
imgBase64 = Convert.ToBase64String(my_image_byte_array)
回答by Sauer Vousstheitroad
My "OpenFileDialog" name is "file". When a "button" is clicked it will show a pop up dialog for selecting jpg, jpeg, png image files, it can also add bmp or any image file type. Then after the selection of a image file it will show on "PictureBox" i name it as "picboxProfileID".
我的“OpenFileDialog”名称是“file”。单击“按钮”时，会弹出一个对话框，用于选择 jpg、jpeg、png 图像文件，还可以添加 bmp 或任何图像文件类型。然后在选择图像文件后，它将显示在“PictureBox”上，我将其命名为“picboxProfileID”。
In Visual Basic:
在 Visual Basic 中：
file.Filter = "image file (*.jpg, *.jpeg, *.png) | *.jpg; *.jpeg; *.png | all files (*.*) | *.*"
If (file.ShowDialog <> Windows.Forms.DialogResult.Cancel) Then
picboxProfileID.Image = Image.FromFile(file.FileName)
picboxProfileID.ImageLocation = file.FileName
txtName.Text = file.FileName
My.Computer.Network.UploadFile(file.FileName, "http://localhost/VTVTS/uploadImageSample.php")
Else
picboxProfileID.Image = Nothing
End If
The destination of the file uploaded will be uploaded on the "images/" of the parent folder php file created.
上传文件的目的地将上传到创建的父文件夹 php 文件的“images/”。
In PHP:
在 PHP 中：
<?php
$response = array();
$image = $_FILES['file'];
$imageName = $image['name'];
$imageTmpName = $image['tmp_name'];
$imageSize = $image['size'];
$imageError = $image['error'];
$imageType = $image['type'];
$fileExt = explode('.', $imageName);
$fileActualExt = strtolower(end($fileExt));
$allowed = array('jpg', 'jpeg', 'png');
if(in_array($fileActualExt, $allowed)){
$fileNameNew = uniqid('', true).".".$fileActualExt;
$fileDestination = 'images/'.$fileNameNew;
$newDestination = move_uploaded_file($imageTmpName, $fileDestination);
$response['error'] = false;
$response['message'] = "Upload Image Successful";
}else{
$response['error'] = true;
$response['message'] = "You cannot upload files of this type!";
}
echo json_encode($response);
Happy Coding!
快乐编码！
