QLPreviewController 自定义标题

QLPreviewItem的previewItemTitle是readOnly，所以QLPreviewController自定义标题可以通过定制PreviewItem类来实现，新建一个QLPreviewItemCustom继承自NSObject：

#import <Foundation/Foundation.h>
#import <QuickLook/QuickLook.h>

@interface QLPreviewItemCustom : NSObject <QLPreviewItem>

@property (nonatomic,readwrite) NSURL * previewItemURL;

@property (nonatomic,readwrite) NSString * previewItemTitle;

@end

然后在previewController返回QLPreviewItem里面重载

- (id<QLPreviewItem>)previewController:(QLPreviewController*)controller previewItemAtIndex:(NSInteger)index
{
    QLPreviewItemCustom * previewItem = [QLPreviewItemCustom new];
    previewItem.previewItemTitle = @"Title"；
    previewItem.previewItemURL = self.pdfURL;
    return previewItem;
}