swift3-将图像上传到Web服务器

Question

I am trying to upload an image that is chosen from a UIImagePickerController to my web server hosted on AWS. I am following this tutorial: https://www.udemy.com/swift-php-mysql-user-sign-up-sign-in-sign-out-and-more/learn/v4/overview and I am getting a bunch of Argument labels '(_:)' do not match any available overloads errors. I've tried searching this error but I havent found anything that relates to my current code. I'm not using the original code in the tutorial, I'm trying to translate it to Swift3 and use the following answer: iOS swift NSMutableData has no member appendString to follow best coding practices. Here is my current code:

func createBodyWithParameters(_ parameters: [String: String]?, filePathKey: String?, imageDataKey: Data, boundary: String) -> Data {
        var body = Data();

        if parameters != nil {
            for (key, value) in parameters! {
                body.append(Data("--\(boundary)\r\n"))
                body.append(Data("Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n"))
                body.append(Data("\(value)\r\n"))
            }
        }

        let filename = "user-profile.jpg"

        let mimetype = "image/jpg"

        body.append(Data("--\(boundary)\r\n"))
        body.append(Data("Content-Disposition: form-data; name=\"\(filePathKey!)\"; filename=\"\(filename)\"\r\n"))
        body.append(Data("Content-Type: \(mimetype)\r\n\r\n"))
        body.append(imageDataKey)
        body.append(Data("\r\n"))



        body.append(Data("--\(boundary)--\r\n"))

        return body as Data
    }

Can someone explain what I'm doing wrong? Thanks!

Answer 1

You cannot initialize Data like this:

Data("foo")

What you can do is:

Data("foo".utf8)

Like in the link you provided. (You are missing the .utf8)

EDIT: Yes the guy said he didn't want to use that code, but hear me out, this version of the extension doesn't allow lossy connection, and as long as you write anything inside the string, data will never be nil.

extension NSMutableData {
   func appendString(_ string: String) {
        let data = string.data(using: String.Encoding.utf8, allowLossyConversion: false)
        append(data!)
    }
}

Usage:

body.appendString("foo")

Just initialize body like this:

var body = NSMutableData()

And return like this

return body as Data

Answer 2

Try this code. You can use this code for uploading images to webserver in swift3

 func generateBoundaryString() -> String
{
    return "Boundary-\(NSUUID().uuidString)"
}

func photoDataToFormData(parameters: [String: String]?, data: Data, boundary:String, fileName:String) -> Data
{
    var fullData = Data()

    if parameters != nil {
        for (key, value) in parameters! {

            print ("Key: \(key), Value: \(value)")
            let str = "--\(boundary)\r\n" + "Content-Disposition: form-data; name=\"\(key)\"\r\n\r\n" + "\(value)\r\n"
            let data = str.data(using: String.Encoding.utf8, allowLossyConversion: true)

            fullData.append(data!)
        }
    }

    // 1 - Boundary should start with --
    let lineOne = "--" + boundary + "\r\n"
    fullData.append(lineOne.data(using: String.Encoding.utf8, allowLossyConversion: false)!)

    // 2
    let lineTwo = "Content-Disposition: form-data; name=\"image\"; filename=\"" + fileName + "\"\r\n"
    NSLog(lineTwo)
    fullData.append(lineTwo.data(using: String.Encoding.utf8, allowLossyConversion: false)!)

    // 3
    let lineThree = "Content-Type: image/jpg\r\n\r\n"
    fullData.append(lineThree.data(using: String.Encoding.utf8, allowLossyConversion: false)!)

    // 4
    fullData.append(data)

    // 5
    let lineFive = "\r\n"
    fullData.append(lineFive.data(using: String.Encoding.utf8, allowLossyConversion: false)!)

    // 6 - The end. Notice -- at the start and at the end
    let lineSix = "--" + boundary + "--\r\n"
    fullData.append(lineSix.data(using: String.Encoding.utf8, allowLossyConversion: false)!)
    return fullData
}

After the above code you need to call a function before the task in the Api function. I have mention that code below.

 let imageData = UIImageJPEGRepresentation(profileImage.image!, 0.5)

 let boundary = generateBoundaryString()

 let fullData = photoDataToFormData(parameters: parameters as? [String : 
 String], data: imageData!, boundary: boundary, fileName: "Test.jpg")

 request.setValue("multipart/form-data; boundary=" + boundary, 
 forHTTPHeaderField: "Content-Type")

    // REQUIRED!
 request.setValue(String(fullData.count), forHTTPHeaderField: "Content-
 Length")

 request.httpBody = fullData

Answer 3

I has solved This problem in swift 4 by adding the following lines after class ViewController:

func generateBoundaryString() -> String {
    return "Boundary-\(NSUUID().uuidString)"
}

extension NSMutableData {
    func appendString(string: String) {
        let data = string.data(using: String.Encoding.utf8, allowLossyConversion: true)
        append(data!)
    }
}

I mean class Viewcontroller the class that created when you add ViewController to your project. example next class:

   class ViewController2: UIViewController ,UINavigationControllerDelegate , UIImagePickerControllerDelegate{
      // my code
    }