我正在使用文件手提包PNG和JPEG从解析下载图像。
当图像下载到应用程序时，我需要确定文件类型是什么，以便我可以相应地处理图像。
看看uiimageview的API并进行搜索，但在swift中找不到任何解决方案。
赞赏任何输入
尝试从PFFIle获取网址§：
let imageURLFromParse = NSURL(string : caseImageFile2.url);
// Error here: 'NSURL?' does not have a member named 'pathExtension'
if(imageURLFromParse.pathExtension!.lowercaseString == ".jpg" || imageURLFromParse.pathExtension.lowercaseString == ".jpeg"){
println("Parse image ext is a jpg: \(imageURLFromParse.pathExtension.lowercaseString)");
fileExtenion = ".jpg";
} else {
println("Parse image is a png: \(imageURLFromParse.pathExtension.lowercaseString)");
fileExtenion = ".png";
}
答案 0 :(得分：14)
Swift 3.0.2的更新
基于Hoa的回答和Kingfisher library
import UIKit
import ImageIO
struct ImageHeaderData{
static var PNG: [UInt8] = [0x89]
static var JPEG: [UInt8] = [0xFF]
static var GIF: [UInt8] = [0x47]
static var TIFF_01: [UInt8] = [0x49]
static var TIFF_02: [UInt8] = [0x4D]
}
enum ImageFormat{
case Unknown, PNG, JPEG, GIF, TIFF
}
extension NSData{
var imageFormat: ImageFormat{
var buffer = [UInt8](repeating: 0, count: 1)
self.getBytes(&buffer, range: NSRange(location: 0,length: 1))
if buffer == ImageHeaderData.PNG
{
return .PNG
} else if buffer == ImageHeaderData.JPEG
{
return .JPEG
} else if buffer == ImageHeaderData.GIF
{
return .GIF
} else if buffer == ImageHeaderData.TIFF_01 || buffer == ImageHeaderData.TIFF_02{
return .TIFF
} else{
return .Unknown
}
}
}
用法
let imageURLFromParse = NSURL(string : "https://i.stack.imgur.com/R64uj.jpg")
let imageData = NSData(contentsOf: imageURLFromParse! as URL)
print(imageData!.imageFormat)
您可以将此功能用于本地和在线图像。
答案 1 :(得分：4)
您必须以二进制形式获取图像的第一个字节。该字节表示哪种图像类型。这是我用于项目但在Objective-c中的代码：
uint8_t c;
[_receivedData getBytes:&c length:1];
NSString *extension = @"jpg";
switch (c) {
case 0xFF:
{
extension = @"jpg";
}
case 0x89:
{
extension = @"png";
}
break;
case 0x47:
{
extension = @"gif";
}
break;
case 0x49:
case 0x4D:
{
extension = @"tiff";
}
break;
default:
FLog(@"unknown image type");
}
在swift中尝试使用此功能（1.2，否则必须使用var ext）：
func imageType(imgData : NSData) -> String
{
var c = [UInt8](count: 1, repeatedValue: 0)
imgData.getBytes(&c, length: 1)
let ext : String
switch (c[0]) {
case 0xFF:
ext = "jpg"
case 0x89:
ext = "png"
case 0x47:
ext = "gif"
case 0x49, 0x4D :
ext = "tiff"
default:
ext = "" //unknown
}
return ext
}
答案 2 :(得分：1)
我想知道在我选择之后我的图像是什么扩展名。我用过这个：
func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
if (!(picker.sourceType == UIImagePickerControllerSourceType.Camera)) {
let assetPath = info[UIImagePickerControllerReferenceURL] as! NSURL
if assetPath.absoluteString.hasSuffix("JPG") {
答案 3 :(得分：1)
您可以在项目https://github.com/bonyadmitr/ImageFormat
中进行测试添加到项目
import Foundation
/// can be done "heic", "heix", "hevc", "hevx"
enum ImageFormat: String {
case png, jpg, gif, tiff, webp, heic, unknown
}
extension ImageFormat {
static func get(from data: Data) -> ImageFormat {
switch data[0] {
case 0x89:
return .png
case 0xFF:
return .jpg
case 0x47:
return .gif
case 0x49, 0x4D:
return .tiff
case 0x52 where data.count >= 12:
let subdata = data[0...11]
if let dataString = String(data: subdata, encoding: .ascii),
dataString.hasPrefix("RIFF"),
dataString.hasSuffix("WEBP")
{
return .webp
}
case 0x00 where data.count >= 12 :
let subdata = data[8...11]
if let dataString = String(data: subdata, encoding: .ascii),
Set(["heic", "heix", "hevc", "hevx"]).contains(dataString)
///OLD: "ftypheic", "ftypheix", "ftyphevc", "ftyphevx"
{
return .heic
}
default:
break
}
return .unknown
}
var contentType: String {
return "image/\(rawValue)"
}
}
使用
for file in ["1.jpg", "2.png", "3.gif", "4.svg", "5.TIF", "6.webp", "7.HEIC"] {
if let data = Data(bundleFileName: file) {
print(file, ImageFormat.get(from: data))
}
}
/// Result
/// 1.jpg jpg
/// 2.png png
/// 3.gif gif
/// 4.svg unknown
/// 5.TIF tiff
/// 6.webp webp
/// 7.HEIC heic
答案 4 :(得分：0)
为什么不简单地执行以下操作：
OneToOneField这将为您提供文件的扩展名。
答案 5 :(得分：0)
@XueYu的回答对我很有帮助。 这是Data而不是NSData的更新
struct ImageHeaderData {
static var PNG: [UInt8] = [0x89]
static var JPEG: [UInt8] = [0xFF]
static var GIF: [UInt8] = [0x47]
static var TIFF_01: [UInt8] = [0x49]
static var TIFF_02: [UInt8] = [0x4D]
}
enum ImageFormat {
case Unknown, PNG, JPEG, GIF, TIFF
}
extension Data {
var imageFormat: ImageFormat {
var buffer = [UInt8](repeating: 0, count: 1)
copyBytes(to: &buffer, from: 0..<1)
if buffer == ImageHeaderData.PNG { return .PNG }
if buffer == ImageHeaderData.JPEG { return .JPEG }
if buffer == ImageHeaderData.GIF { return .GIF }
if buffer == ImageHeaderData.TIFF_01 ||
buffer == ImageHeaderData.TIFF_02 {
return .TIFF
}
return .Unknown
}
}
答案 6 :(得分：0)
此代码将用于 Swift 5 和 iOS 12 。如果使用此代码，则可以获取文档和图片 文件类型
import UIKit
import Photos
class ViewController {
let imagePicker = UIImagePickerController()
override func viewDidLoad() {
super.viewDidLoad()
checkPermission()
}
}
extension ViewController : UINavigationControllerDelegate, UIImagePickerControllerDelegate, UIDocumentPickerDelegate {
func checkPermission() {
let photoAuthorizationStatus = PHPhotoLibrary.authorizationStatus()
switch photoAuthorizationStatus {
case .authorized:
print("Access is granted by user")
accessDocsAndImages()
case .notDetermined:
PHPhotoLibrary.requestAuthorization({ newStatus in
print("status is \(newStatus)")
if newStatus == PHAuthorizationStatus.authorized {
/* do stuff here */
print("success")
}
})
case .restricted:
print("User do not have access to photo album.")
case .denied:
print("User has denied the permission.")
@unknown default:
print("Defults")
}
}
func accessDocsAndImages() {
imagePicker.allowsEditing = true
imagePicker.delegate = self
let optionMenu = UIAlertController(title: nil, message: "Choose Option", preferredStyle: .alert)
let openCameraAction = UIAlertAction(title: "Camera", style: .default, handler: {
(alert: UIAlertAction!) -> Void in
return
})
let openGalleryAction = UIAlertAction(title: "Open Gallery", style: .default, handler: {
(alert: UIAlertAction!) -> Void in
self.imagePicker.sourceType = .photoLibrary
self.present(self.imagePicker, animated: true, completion: nil)
print("Opened gallery")
})
let openDocAction = UIAlertAction(title: "Open Documents", style: .default, handler: {
(alert: UIAlertAction!) -> Void in
print("Opened gallery")
let documentPicker = UIDocumentPickerViewController(documentTypes: ["public.content", "public.item", "public.composite-content", "public.data", "public.database", "public.calendar-event", "public.message", "public.presentation", "public.contact", "public.archive", "public.disk-image", "public.text", "public.plain-text", "public.utf8-plain-text", "public.utf16-external-plain-text", "public.utf16-plain-text", "com.apple.traditional-mac-plain-text", "public.rtf","public.pdf", "public.movie", "public.audiovisual-content", "public.video", "public.audio"], in: .import)
documentPicker.delegate = self
//documentPicker.modalPresentationStyle = .formSheet
documentPicker.allowsMultipleSelection = true
self.present(documentPicker, animated: true, completion: nil)
})
let cancelAction = UIAlertAction(title: "Cancel", style: .cancel, handler: {
(alert: UIAlertAction!) -> Void in
print("cancelled")
})
optionMenu.addAction(openGalleryAction)
optionMenu.addAction(openCameraAction)
optionMenu.addAction(openDocAction)
optionMenu.addAction(cancelAction)
self.present(optionMenu, animated: true, completion: nil)
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
if let asset = info[UIImagePickerController.InfoKey.phAsset] as? PHAsset {
let assetResources = PHAssetResource.assetResources(for: asset)
print(assetResources.first!.originalFilename)
if (assetResources.first!.originalFilename.hasSuffix("JPG")) {
print("jpg")
} else if (assetResources.first!.originalFilename.hasSuffix("JPEG")) {
print("jpeg")
} else if (assetResources.first!.originalFilename.hasSuffix("PNG")) {
print("png")
} else if (assetResources.first!.originalFilename.hasSuffix("GIF")) {
print("gif")
} else if (assetResources.first!.originalFilename.hasSuffix("TIFF")) {
print("tiff")
} else if (assetResources.first!.originalFilename.hasSuffix("WEBP")) {
print("webp")
} else if (assetResources.first!.originalFilename.hasSuffix("HEIC")) {
print("heic")
} else if (assetResources.first!.originalFilename.hasSuffix("HEIX")) {
print("heix")
} else if (assetResources.first!.originalFilename.hasSuffix("HEVC")) {
print("hevc")
} else if (assetResources.first!.originalFilename.hasSuffix("HEVX")) {
print("hevx")
} else {
print("Unknown")
}
}
dismiss(animated: true, completion: nil)
}
private func imagePickerControllerDidCancel(picker: UIImagePickerController) {
dismiss(animated: true, completion: nil)
}
func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentAt url: URL) {
print(url)
}
func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
let cico = urls[0] as URL
print(cico)
print(urls[0])
print(urls[0].lastPathComponent)
print(urls[0].pathExtension)
let urlWithoutFileExtension: URL = urls[0].deletingPathExtension()
let fileNameWithoutExtension: String = urlWithoutFileExtension.lastPathComponent
print(fileNameWithoutExtension)
dismiss(animated: true, completion: nil)
}
func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
print(" cancelled by user")
}
}