macos - 在 Swift、Cocoa、Mac OSX 中将 EXIF 数据设置为 NSImage

Question

如果图像没有 EXIF 数据，我试图将 EXIF 数据设置为 NSImage。实际上我只想设置 DateTimeOriginal。但我的方法行不通。

let completePath = "/Users/stefocdp/image.jpg"
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "dd.MM.yyyy HH:mm:ss"
let folderAttributes: NSDictionary = NSFileManager.defaultManager().attributesOfItemAtPath(completePath, error: nil)!
var dateString: String = dateFormatter.stringFromDate(folderAttributes.objectForKey(NSFileCreationDate) as! NSDate)

for obj in self.image.representations {
    if let rep = obj as? NSBitmapImageRep {
        if rep.valueForProperty(NSImageEXIFData) != nil {
            //will be called if the image has exif data

            // get exif dictonary
            var exifData = rep.valueForProperty(NSImageEXIFData) as! NSDictionary

            //convert CFString to String
            var cfStr:CFString = kCGImagePropertyExifDateTimeOriginal
            var nsTypeString = cfStr as NSString
            var keySwiftString:String = nsTypeString as String

            //get date from exif data
            dateString = exifData.valueForKey(keySwiftString) as! String

            //convert the date to NSDate
            var dateFormatter = NSDateFormatter()
            dateFormatter.dateFormat = "yyyy:MM:dd HH:mm:ss"
            var date = dateFormatter.dateFromString(dateString)

            //convert the NSDate back to String (only because I want another date format)
            dateFormatter.dateFormat = "dd.MM.yyyy HH:mm:ss"
            dateString = dateFormatter.stringFromDate(date!)
        } else {
            //will be called if the image don't has exif data

            //create dictionary for the exif data
            var exifData = Dictionary<String, CFString>()

            //convert the given date string to NSDate
            var dateFormatter = NSDateFormatter()
            dateFormatter.dateFormat = "dd.MM.yyyy HH:mm:ss"
            var date = dateFormatter.dateFromString(dateString)

            //convert it back to String (different date format for exif data)
            dateFormatter.dateFormat = "yyyy:MM:dd HH:mm:ss"
            dateString = dateFormatter.stringFromDate(date!)

            //convert CFString to String
            var cfStr:CFString = kCGImagePropertyExifDateTimeOriginal
            var nsTypeString = cfStr as NSString
            var keySwiftString:String = nsTypeString as String

            //add date to the exifData dictionary
            exifData[keySwiftString] = dateString as CFString

            //set the exifData to the NSBitmapImageRep
            rep.setProperty(NSImageEXIFData, withValue: exifData)

            //add the NSBitmapImageRep to the image
            self.image.addRepresentation(rep)
        }
    }
    else {
        //is not an instance of NSBitmapImageRep
    }
}

如果图像有 exif 数据，我只需从中获取 DateTimeOriginal 并将其存储在名为“dateString”的字符串变量中。但是如果它没有 exif 数据(在“其他”情况下)，我正在创建一个字典来存储日期。然后我将 exif 数据添加到 NSBitmapImageRep。最后我想将这个 imagerep 添加到图像中。我猜最后一步是问题所在。

谁能帮我解决我的问题？

谢谢!

Answer 1

//你可以使用CGImageSourceRef代替NSBitMapImageRef。对于初学者:

let url = NSURL(fileURLWithPath: imgfile) //imgfile = a String of the img file path

let cgiSrc = CGImageSourceCreateWithURL(url,nil)

let cfD:CFDictionaryRef = CGImageSourceCopyPropertiesAtIndex(cgiSrc!, 0, nil)!

let nsDic = NSDictionary(dictionary: cfD)

print(nsDic.description) //verify that it's working