swift -> UIImage图片 / NSData 和 String 相互转化

•  图片 和 String 之间

 

图片转 String

            let image = UIImage();
            let imgData = UIImagePNGRepresentation(image);
            print(imgData?.base64EncodedString())

 

String 转 图片

            let imageStr:String = "iVBORw0KGgoAAAANSUhEUgAAADwAAAA8CAYAAAA6/NlyAAAAAXNSR0IArs4c6QAAABxpRE9UAAAAAg...中间省略若干字符gg==";
            
            if var data: NSData = NSData(base64Encoded: imageStr, options:NSData.Base64DecodingOptions.ignoreUnknownCharacters)
                
            {
                
                if var image: UIImage = UIImage(data: data as Data)
                    
                {
                    
                    let imageView = UIImageView(image: image)
                    self.view.addSubview(imageView)
                    
                }
                
            }

 

 

•   NSData 和 String 之间  

do {
    //data to string
    let data: Data = try Data(contentsOf: url! as URL)
    let str = String(data: data, encoding: String.Encoding.utf8)

    //string to data
    let data:Data = str.data(using: String.Encoding.utf8))!
catch {
    print("Error: (data: contentsOf: url)")
}

 

Base64互转 

let string = "Hello world"

// 将字符串进行UTF8编码成NSData
let utf8EncodeData:NSData! = string.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)

// 将NSData进行base64编码
let base64EncodedString =  utf8EncodeData?.base64EncodedString()
print("encodedString: \(base64EncodedString)")

// 将base64字符串转换成NSData
let base64EncodedData = NSData(base64EncodedString:base64EncodedString,options:NSDataBase64DecodingOptions(rawValue: 0))
// 对NSData数据进行UTF8解码
let stringWithDecode = NSString(data: base64EncodedData!, encoding: NSUTF8StringEncoding)
print("base64String: \(stringWithDecode)")