Question

我使用Obj-C编写的NSData base64Encoding类别。

@interface NSData (Base64)

+ (NSData*)dataFromBase64String:(NSString*)aString;
- (NSString*)base64EncodedString;

@end

最初在Swift 2.2中，我使用它作为：

let dbPassData = NSData(fromBase64String: password)

现在，在Swift 3中，没有任何NSData，而是Data。

如何在swift 3中使用这些类别方法？

将项目转换为Swift 3后，它将该行转换为：

let dbPassData = Data(fromBase64String: password)

产生错误：

参数标签与任何可用的重载都不匹配

Answer 1

In Swift 3, Apple also renamed some initializers and Xcode 8 beta makes some mistakes when converting from 2.2 to 3.

In that case, the initializer was renamed to this:

let data = Data(base64Encoded: "hello")

When you are facing this or similar problems, you can start typing ClassName( and look at the proposed initializers. In most cases, you'll find the new one easily.

Answer 2

NSData仍可在Swift 3中使用，就像String与NSString共存一样。在这种情况下，您需要忽略编译器的建议：

let dbPassData = NSData(fromBase64String: password) as Data

这假设您不希望将Base64类别移植到Swift，或者希望保持与Obj-C代码的兼容性。 Swift 3的Data还提供内置的Base 64转换：

let dbPassData   = Data(base64Encoded: password)
let base64String = data.base64EncodedString(options: [.lineLength64Characters, .endLineWithLineFeed])

在swift-3中访问NS Type类类别

2 个答案: