如何将按钮添加到QLPreviewController中

Question

是否可以将新按钮添加到工具栏或QLpreviewController右上方的actionButton中？

如果是，我如何编写代码？

Answer 1

虽然QLPreviewController是UIViewController的一个子类，但更改导航项无效。例如，这段代码理论上应该工作，但不会：

QLPreviewController *previewController = [[QLPreviewController alloc] init]; 
previewController.navigationItem.rightBarButtonItem = 
    [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction 
          target:self action:@selector(share)]

你可以，但是，一个工具栏添加到QLPreviewController。首先设置你的工具栏，显示视图时加载：

- (void)viewWillAppear:(BOOL)animated 
{ 
    [super viewWillAppear:animated]; 
    self.navigationController.toolbarHidden = NO; 
} 

- (void)viewWillDisappear:(BOOL)animated 
{ 
    [super viewWillDisappear:animated]; 
    self.navigationController.toolbarHidden = YES; 
} 

下一步，设置您的toolbarItems从QLPreviewController代表：

- (id)previewController:(QLPreviewController *)previewController 
       previewItemAtIndex:(NSInteger)idx { 

UIBarButtonItem *testButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Test" 
               style:UIBarButtonItemStylePlain 
               target:self 
               action:@selector(testButtonTapped:)]; 

NSArray *myToolbarItems = [NSArray arrayWithObjects:testButtonItem, nil]; 
previewController.toolbarItems = myToolbarItems; 
[testButtonItem release]; 
}