如何使用Swift在OS X上读取Finder图标（左侧源列表） [英] How to read Finder icons (left source list) on OS X using Swift

问题描述

我尝试读取有关在左侧源列表中的finder中显示的图标的信息。我已经尝试了 NSFileManager 与以下选项

• NSURLEffectiveIconKey 图标读取与finder中的不同


• NSURLCustomIconKey - 返回nil


• NSURLThumbnailKey - 返回nil


• NSThumbnail1024x1024SizeKey - 返回nil

我设法使用NSFileManager读取所有挂载的设备，但我不知道如何读取与设备连接的图标？也许有人有任何想法或暗示。

我也尝试使用

  var image：NSImage = NSWorkspace.sharedWorkspace（）。iconForFile（（url as！NSURL）.path！）
  

但它返回与 NSURLEffectiveIconKey

相同的图片

谢谢！

解决方案

此答案是对

更新2

请注意，虽然它已被弃用，仍然可以工作。之前的解决方案中的 [LSSharedFileListItemRef] 的转换现在被忽略，因此我们必须转换为 NSArray 项目后：

 如果let items = itemsCF.takeRetainedValue（）as？ NSArray {
 for item in items {
 let icon = LSSharedFileListItemCopyIconRef（item as！LSSharedFileListItem）
 let image = NSImage（iconRef：icon）
 // use image ... 
 
} 
} 
  

I try to read information about icons that are shown in finder on left source list. I tried already NSFileManager with following options

• NSURLEffectiveIconKey icon read is not the same as in finder
• NSURLCustomIconKey - returns nil
• NSURLThumbnailKey - returns nil
• NSThumbnail1024x1024SizeKey - returns nil

I managed to read all mounted devices using NSFileManager but I have no clue how to read icons connected with devices? Maybe someone has any idea or a hint.

I also tried to use

var image: NSImage = NSWorkspace.sharedWorkspace().iconForFile((url as! NSURL).path!)

but it returns the same image as NSURLEffectiveIconKey

Thanks!

解决方案

This answer is a translation to Swift 1.2 of Ken Thomases's Objective-C answer.

All credits go to Ken Thomases, this is just a translation of his awesome answer.

let listBase = LSSharedFileListCreate(kCFAllocatorDefault, kLSSharedFileListFavoriteVolumes.takeUnretainedValue(), NSMutableDictionary())
let list = listBase.takeRetainedValue() as LSSharedFileList

var seed:UInt32 = 0
let itemsCF = LSSharedFileListCopySnapshot(list, &seed)

if let items = itemsCF.takeRetainedValue() as? [LSSharedFileListItemRef] {
    for item in items {
        let icon = LSSharedFileListItemCopyIconRef(item)
        let image = NSImage(iconRef: icon)
        // use image ...
    }
}

Explanations:

When translating Ken's answer from Objective-C to try and use it I encountered some difficulties, this is the reason why I made this answer.

First problem was with LSSharedFileListCreate, the method signature in Swift didn't accept nil as its first parameter. I had to find a constant representing a CFAllocator: kCFAllocatorDefault. And the third parameter didn't accept nil either, so I put a dummy unused NSMutableDictionary to keep the compiler happy.

Also the "seed" parameter for LSSharedFileListCopySnapshot didn't accept the usual var seed:Uint32? for the inout, I had to give a default value to seed.

For deciding when to use takeRetainedValue or takeUnRetainedValue when using these APIs I referred to this answer.

Last, I had to cast the returned array as a Swift array of LSSharedFileListItemRef elements (it was initially inferred as a CFArray by the compiler).

Update

This has been deprecated in OS X El Capitan 10.11 (thanks @patmar)

Update 2

Note that while it's been deprecated it still works. The cast as [LSSharedFileListItemRef] in the previous solution is now ignored so we have to cast as NSArray instead then cast the item later:

if let items = itemsCF.takeRetainedValue() as? NSArray {
    for item in items {
        let icon = LSSharedFileListItemCopyIconRef(item as! LSSharedFileListItem)
        let image = NSImage(iconRef: icon)
        // use image ...

    }
}

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