Ios 从NSArray到Swift中的阵列

我有一个NSArray，叫做RetrabumArray，它是这样的：

(
    {
    coverable = 1;
    "mer_thumb" = "http://www.abcd.org/Uploads/Images/mer_album/56b6fb29d2786.jpg";
},
    {
    coverable = 0;
    "mer_thumb" = "http://www.abcd.org/Uploads/Images/mer_album/56b716368a84f.jpg";
},
    {
    coverable = 0;
    "mer_thumb" = "http://www.abcd.org/Uploads/Images/mer_album/56b71f59cd6b3.jpg";
},
    {
    coverable = 0;
    "mer_thumb" = "http://www.abcd.org/Uploads/Images/mer_album/56b7241fcfe50.jpg";
},
    {
    coverable = 0;
    "mer_thumb" = "http://www.abcd.org/Uploads/Images/mer_album/56b73d9e2790e.jpg";
}    )

我想将NSArray转换为字符串数组，该数组只包含与键mer_thumb相对的值，因此我可以得到以下内容：

["http://www.abcd.org/Uploads/Images/mer_album/56b6fb29d2786.jpg", "http://www.abcd.org/Uploads/Images/mer_album/56b716368a84f.jpg", "http://www.abcd.org/Uploads/Images/mer_album/56b71f59cd6b3.jpg", "http://www.abcd.org/Uploads/Images/mer_album/56b7241fcfe50.jpg", "http://www.abcd.org/Uploads/Images/mer_album/56b73d9e2790e.jpg"]

---

有人能帮我吗？谢谢

未测试，但这应该可以：

if let array = retAlbumArray.valueForKey("mer_thumb") as? [String] {
    ...
}

---

我对你的答案投了更高的票，因为它比我的答案更快，尽管map函数按原样返回的数组将是[AnyObject？]类型。@rog你可以用元素[mer_thumb]按原样修复它吗？字符串我还建议使用flatMap，而不仅仅是map，因为这将消除任何具有nil值的条目。

retAlbumArray.map({ element in
    element["mer_thumb"] as? String
})