stringByReplacingCharactersInRange如何在swift中工作？

Question

我有這樣的代碼在Objective-C：

[textField.text stringByReplacingCharactersInRange:range withString:string]; 

嘗試轉換爲迅速，像這樣：

textField.text.stringByReplacingCharactersInRange(range, withString: string) 

但是編譯器說，Int is not identical to 'String.index'

我應該如何修改體現在哪裏？

我同時使用的Objective-C/SWIFT表達的UITextFieldDelegate方法：

func textField(textField: UITextField!, 
    shouldChangeCharactersInRange range: NSRange, 
    replacementString string: String!) -> Bool { 

Answer 1

使用bridgeToObjectiveC()

textField.text.bridgeToObjectiveC().stringByReplacingCharactersInRange(range, withString: string) 

將更加明確

var st = "abc" 
str.bridgeToObjectiveC().stringByReplacingCharactersInRange(NSMakeRange(2,1), withString:"r") 

顯式轉換也可以做NSString，它不是需要bridgeToObjectiveC

var st = "abc" as NSString 
let abc = st.stringByReplacingCharactersInRange(NSMakeRange(2, 3), withString: "abc")