如何转换非托管的<CFData>到 NSData? [英] How to convert unmanaged&lt;CFData&gt; to NSData?

问题描述

我需要将我的 Objective-C 转换为 Swift 以从地址簿中获取联系人的图像.但是我从 CFData 到 NSData 的 for cast 出现错误，我不知道如何使这个工作.我该怎么做才能使其正常工作?

I need to convert my Objective-C to Swift to get an image of a contact from the Address Book. But I get an error with for cast from CFData to NSData and I don't know how make this work. What can I do to make this work correctly?

在 Objective-C 中:

In Objective-C:

ABRecordID contactID = ABRecordGetRecordID(contactRef);
ABAddressBookRef addressBook = ABAddressBookCreate();

ABRecordRef origContactRef = ABAddressBookGetPersonWithRecordID(addressBook, contactID);

if (ABPersonHasImageData(origContactRef)) {
    NSData *imgData = (NSData*)ABPersonCopyImageDataWithFormat(origContactRef, kABPersonImageFormatOriginalSize);
    img = [UIImage imageWithData: imgData]; 

    [imgData release];
}

CFRelease(addressBook);

return img;

在 Swift 中:

var image: UIImage!

if ABPersonHasImageData(person) {
    var imgData = (ABPersonCopyImageDataWithFormat(person, kABPersonImageFormatOriginalSize))
    image = UIImage.imageWithData(imgData) //Here get the error 
}

推荐答案

如使用 Cocoa 数据类型，您必须使用 takeUnretainedValue() 或 takeRetainedValue() 将非托管对象转换为内存托管对象.你的情况

As explained in Working with Cocoa Data Types, you have to convert the unmanaged object to a memory managed object with takeUnretainedValue() or takeRetainedValue(). In your case

if (ABPersonHasImageData(person)) {
    let imgData = ABPersonCopyImageDataWithFormat(person, kABPersonImageFormatOriginalSize).takeRetainedValue()
    let image = UIImage(data: imgData)
}

因为 ABPersonCopyImageDataWithFormat() 返回一个 (+1) 保留值.

because ABPersonCopyImageDataWithFormat() returns a (+1) retained value.

这篇关于如何转换非托管的<CFData>到 NSData?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！