Swift-AWS S3从照片库上传图像并下载

Z时代
2024-01-10
分类：问答

我看过许多亚马逊文档，但是找不到足够的信息来使用Swift将图像上传和下载到S3。

我怎样才能做到这一点？

回答：

经过大量研究后，我开始了这项工作，

import AWSS3
import AWSCore

我认为您已经实施UIImagePickerControllerDelegate了。

创建用于保存网址的变量：
```
var imageURL = NSURL()
```

创建上传完成处理程序obj：

var uploadCompletionHandler: AWSS3TransferUtilityUploadCompletionHandlerBlock?

从中获取图片网址imagePickerController(_:didFinishPickingMediaWithInfo:)：

imageURL在此委托方法中设置的值：

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]){
//getting details of image
let uploadFileURL = info[UIImagePickerControllerReferenceURL] as! NSURL
let imageName = uploadFileURL.lastPathComponent
let documentDirectory = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).first! as String
// getting local path
let localPath = (documentDirectory as NSString).stringByAppendingPathComponent(imageName!)
//getting actual image
let image = info[UIImagePickerControllerOriginalImage] as! UIImage
let data = UIImagePNGRepresentation(image)
data!.writeToFile(localPath, atomically: true)
let imageData = NSData(contentsOfFile: localPath)!
imageURL = NSURL(fileURLWithPath: localPath)
picker.dismissViewControllerAnimated(true, completion: nil)

}

设置为“将图像上传到存储桶” uploadImage后，调用此方法imageURL：

func uploadImage(){
    //defining bucket and upload file name
    let S3BucketName: String = "bucketName"
    let S3UploadKeyName: String = "public/testImage.jpg"
    let expression = AWSS3TransferUtilityUploadExpression()
    expression.uploadProgress = {(task: AWSS3TransferUtilityTask, bytesSent: Int64, totalBytesSent: Int64, totalBytesExpectedToSend: Int64) in
        dispatch_async(dispatch_get_main_queue(), {
            let progress = Float(totalBytesSent) / Float(totalBytesExpectedToSend)
            print("Progress is: \(progress)")
        })
    }
    self.uploadCompletionHandler = { (task, error) -> Void in
        dispatch_async(dispatch_get_main_queue(), {
            if ((error) != nil){
                print("Failed with error")
                print("Error: \(error!)");
            }
            else{
                print("Sucess")
            }
        })
    }
    let transferUtility = AWSS3TransferUtility.defaultS3TransferUtility()
    transferUtility.uploadFile(imageURL, bucket: S3BucketName, key: S3UploadKeyName, contentType: "image/jpeg", expression: expression, completionHander: uploadCompletionHandler).continueWithBlock { (task) -> AnyObject! in
        if let error = task.error {
            print("Error: \(error.localizedDescription)")
        }
        if let exception = task.exception {
            print("Exception: \(exception.description)")
        }
        if let _ = task.result {
            print("Upload Starting!")
        }
        return nil;
    }
}

func downloadImage(){
    var completionHandler: AWSS3TransferUtilityDownloadCompletionHandlerBlock?
    let S3BucketName: String = "bucketName"
    let S3DownloadKeyName: String = "public/testImage.jpg"
    let expression = AWSS3TransferUtilityDownloadExpression()
    expression.downloadProgress = {(task: AWSS3TransferUtilityTask, bytesSent: Int64, totalBytesSent: Int64, totalBytesExpectedToSend: Int64) in
        dispatch_async(dispatch_get_main_queue(), {
            let progress = Float(totalBytesSent) / Float(totalBytesExpectedToSend)
            print("Progress is: \(progress)")
        })
    }
    completionHandler = { (task, location, data, error) -> Void in
        dispatch_async(dispatch_get_main_queue(), {
            if ((error) != nil){
                print("Failed with error")
                print("Error: \(error!)")
            }
            else{
                //Set your image
                var downloadedImage = UIImage(data: data!)
            }
        })
    }
    let transferUtility = AWSS3TransferUtility.defaultS3TransferUtility()
    transferUtility.downloadToURL(nil, bucket: S3BucketName, key: S3DownloadKeyName, expression: expression, completionHander: completionHandler).continueWithBlock { (task) -> AnyObject! in
        if let error = task.error {
            print("Error: \(error.localizedDescription)")
        }
        if let exception = task.exception {
            print("Exception: \(exception.description)")
        }
        if let _ = task.result {
            print("Download Starting!")
        }
        return nil;
    }
}