获取NSPasteboardTypeFileURL的UTI

Question

NSFilenamesPboardType在10.14就被否决了，建议使用NSPasteboardTypeFileURL。这给了我文件名

file:///.file/id=6571367.12885025918

而NSWorkspace也无法让UTI脱离困境。

如何从NSPasteboardTypeFileURL获取UTI？

旧代码：

- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender
{
    NSDragOperation sourceDragMask = [sender draggingSourceOperationMask];
    NSDragOperation resultingDragMask = NSDragOperationNone;
    NSPasteboard *pboard = [sender draggingPasteboard];

    if ([[pboard types] containsObject:NSFilenamesPboardType]) {
        NSArray <NSString *>*list = [pboard propertyListForType:NSFilenamesPboardType];
        NSString *firstItem = [list objectAtIndexedSubscript:0];
        NSError *error;
        NSString *UTI = [[NSWorkspace sharedWorkspace] typeOfFile:firstItem error:&error];
        if (!error) {
            if ([[NSImage imageTypes] containsObject:UTI]) {
                resultingDragMask = NSDragOperationCopy;
            }
        }

    } else if ([[pboard types] containsObject:NSPasteboardTypeTIFF]) {
        resultingDragMask = NSDragOperationCopy;
    }

    if (sourceDragMask & NSDragOperationCopy && resultingDragMask & NSDragOperationCopy) {
        return NSDragOperationCopy;
    }
    return NSDragOperationNone;
}

使用NSPasteboardTypeFileURL，我得到了不存在状态文件的错误。从纸板上拖来的：

打印错误描述: Error Domain=NSCocoaErrorDomain Code=260“文件”“id=6571367.12885025918”无法打开，因为没有这样的文件。UserInfo={NSURL=file:/.file/id=6571367.12885025918 - file:///Users/xxx/Library/Containers/com.xxx.imageviewfix/Data/，NSFilePath=/Users/xxx/Library/Containers/com.xxx.imageviewfix/Data/file:/.file/id=6571367.12885025918，NSUnderlyingError=0x600000c70d80 {Error Domain=NSPOSIXErrorDomain Code=2“无此类文件或目录”}}

Answer 1

我很晚才回答这个问题，但我发现这是可行的：

  NSArray<Class> *classes = @[[NSURL class]];
  NSDictionary *options = @{};
  NSArray<NSURL*> *files = [pboard readObjectsForClasses:classes options:options];

  for (NSURL *url in files)
  {
     NSString *str = [url path];

     // TODO: do something with str.
  }

与另一个答案不同，删除多个文件适用于这种方法。

Answer 2

获取NSURL对象的路径将获得原始文件名。唯一缺少的是NSFilenamesPboardType用来提供的文件路径数组。

NSString *fileURL = [[NSURL URLFromPasteboard:pboard] path];

更新代码：

- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender
{
    NSDragOperation sourceDragMask = [sender draggingSourceOperationMask];
    NSDragOperation resultingDragMask = NSDragOperationNone;
    NSPasteboard *pboard = [sender draggingPasteboard];

    if ([[pboard types] containsObject:NSPasteboardTypeFileURL]) {
        NSString *fileURL = [[NSURL URLFromPasteboard:pboard] path];
        NSError *error;
        NSString *UTI = [[NSWorkspace sharedWorkspace] typeOfFile:fileURL error:&error];
        if (!error) {
            if ([[NSImage imageTypes] containsObject:UTI]) {
                resultingDragMask = NSDragOperationCopy;
            }
        }

    } else if ([[pboard types] containsObject:NSPasteboardTypeTIFF]) {
        resultingDragMask = NSDragOperationCopy;
    }

    if (sourceDragMask & NSDragOperationCopy && resultingDragMask & NSDragOperationCopy) {
        return NSDragOperationCopy;
    }
    return NSDragOperationNone;
}