斯威夫特4：无法将类型的值“数据”预期参数类型“数据”

Question

我使用的Xcode 9，斯威夫特4

我尝试使用下面的代码，以显示从URL ImageView的图像：

func getImageFromUrl(sourceUrl: String) -> UIImage { 
     let url = URL(string: sourceUrl) 
     let dict = NSDictionary(contentsOf: url!) 
     let data = Data(dictionary: dict!) 
     let image = UIImage(data: data!) 
     return image 
} 

但我在let image = UIImage(data: data!)中遇到了错误。

编译器说：

无法将类型“数据”预期参数类型“数据”

我在做什么错误的价值？

Answer 1

试试这个，

func getImageFromUrl(sourceUrl: String) -> UIImage { 
    let imageData = try! Data(contentsOf: (URL(string: sourceUrl))!) 
    let image = UIImage(data: imageData) 
    return image! 
} 

//代码的另一个版本，您可以检查零也

func getImageFromUrl(sourceUrl: String) -> UIImage? { 
    if let imageData = try? Data(contentsOf:URL(string: sourceUrl)) { 
    return UIImage(data: imageData) 
    } 
return nil 
} 

Answer 2

/// Returns nil if image data is not correct or some network error has happened 
func getImageFromUrl(sourceUrl: String) -> UIImage? { 
    if let url = URL(string: sourceUrl) { 
    if let imageData = try? Data(contentsOf:url) { 
     return UIImage(data: imageData) 
    } 
    } 
    return nil 
}