我已阅读有关QLPreviewController
在某些条件下不能工作的其他信息。这一个让我难以承受:QLPreviewController适用于iOS 6;不在iOS 7
RHBlobCollection
和RHBlobView
是模型/视图对象,它们分别保存提前高速缓存的集合和单个可显示文件。
RHBlobView.m:
- (IBAction) handleBlobTap:(UITapGestureRecognizer *)sender
{
QLPreviewController *previewController = [[QLPreviewController alloc] init];
// view tag is index in array of blobs
[previewController setCurrentPreviewItemIndex:self.tag];
// blobContainer is type RHBlobCollection
[previewController setDataSource:self.blobContainer];
UINavigationController *navController = (UINavigationController *)[[[[UIApplication sharedApplication] delegate] window] rootViewController];
[navController pushViewController:previewController animated:YES];
}
RHBlobCollection.m:
- (NSInteger) numberOfPreviewItemsInPreviewController:(QLPreviewController *)controller
{
return [self.blobs count];
}
- (id <QLPreviewItem>) previewController:(QLPreviewController *)controller
previewItemAtIndex:(NSInteger)index
{
RHBlobView *blob = self.blobs[(NSUInteger) index];
NSURL *fileURL = [RHCacheManager cachedFileURLForFilename:blob.filename withKey:blob.blobID];
// URL proper?
BOOL __unused proof1 = [fileURL isFileURL];
// QLPreviewController can stomach it?
BOOL __unused proof2 = [QLPreviewController canPreviewItem:fileURL];
// Cached file actually exists?
NSString *proof3path = [[fileURL resourceSpecifier] stringByReplacingPercentEscapesUsingEncoding:NSISOLatin1StringEncoding];
BOOL __unused proof3 = [[NSFileManager defaultManager] fileExistsAtPath:proof3path];
// Unless we're dealing with thumbnails, we're done. Return the URL of the resource.
if (! [blob hasThumbnails])
{
return fileURL;
}
// Process thumbnails into .pdf file for display...
proof1
,proof2
和proof3
都返回YES
。拉出一个单独的概念验证项目,QLPreviewController
按照它应该做的。然而,在我的完整应用程序项目中,它可以在iOS 6下运行,但在iOS 7下挂载在“加载...”上。
我的直觉告诉我,它应该与格式错误的文件URL有关或路径,但我的小测试显示一切都是copasetic。有没有其他人有这个问题?
当我计算numberOfPreviewItemsInPreviewController中的项数不正确时,我得到了这个问题。 –
@那个家伙,我证实了这个数字是正确的。 – rsswtmr
@NewDev,不,索引始终是被请求文档的索引。第一份文件为0,第二份为1等。 – rsswtmr