How can I hide the print button in QLPreviewController
In IOS5, this code works
QLPreviewController *previewController = [[QLPreviewController alloc] init];
previewController.dataSource = self;
previewController.delegate = self;
previewController.currentPreviewItemIndex = _fileidx;
[[self navigationController] pushViewController:previewController animated:YES];
[previewController.navigationItem setRightBarButtonItem:nil];
but in IOS6, it does`t.
i managed to do it by creating a timer to check for the navigation item and remove it
myTimer = [NSTimer scheduledTimerWithTimeInterval:1.0
target:self
selector:@selector(hideRightButton:)
userInfo:nil
repeats:YES];
- (void)hideRightButton:(NSTimer *)timer {
[self inspectSubviewsForView:self.view];
}
- (void)inspectSubviewsForView:(UIView *)view
{
for (UIView *subview in view.subviews)
{
NSLog(@"class detected %@",[subview description]);
if ([subview isKindOfClass:[UINavigationBar class]])
{
UINavigationBar *bar = (UINavigationBar *)subview;
if ([[bar items] count] > 0)
{
UINavigationItem *navItem = [[bar items] objectAtIndex:0];
[navItem setRightBarButtonItem:nil];
{
}
if ([subview isKindOfClass:[UIView class]] && [[subview subviews] count] > 0)
{
[self inspectSubviewsForView:subview];
}
}
}
[self inspectSubviewsForView:subview];
}
}
The issue is that the button seems to be regenerated once the document is ready. I cannot really define "ready" but I wrote a test app and noticed a couple of things:
The above hack only works if the document being shown is "ready" fast enough. Big documents take longer. I came up with a two step solution:
Here's some code:
This is from ViewDidAppear():
Setup a timer that keeps on hiding the button.
NSTimer oTimer = NSTimer.CreateRepeatingTimer(0.2, this.HidePrintButton);
NSRunLoop.Current.AddTimer(oTimer, NSRunLoopMode.Default);
private void HidePrintButton()
{
if(this.oNavItem == null)
{
return;
}
this.InvokeOnMainThread(
delegate {
this.oNavItem.SetRightBarButtonItems( new UIBarButtonItem[0], false );
} );
}
This searches the navigation item:
/// <summary>
/// Finds the first navigation item inside a view hierachy.
/// </summary>
/// <param name='oCurrentView'>the view to start searching from</param>
/// <param name='oItem'>will be set if the navigation item was found</param>
public static void FindNavigationItem(UIView oCurrentView, ref UINavigationItem oItem)
{
if(oItem != null || oCurrentView == null || oCurrentView.Subviews == null || oCurrentView.Subviews.Length <= 0)
{
return;
}
// Check if a UINavigationBar was found. This will contain the UINavigationItem.
if(oCurrentView is UINavigationBar)
{
UINavigationBar oBar = (UINavigationBar)oCurrentView;
if(oBar.Items != null && oBar.Items.Length > 0)
{
oItem = oBar.Items[0];
}
return;
}
// Recursively loop all sub views and keep on searching.
foreach (var oSubView in oCurrentView.Subviews)
{
FindNavigationItem(oSubView, ref oItem);
if(oItem != null)
{
break;
}
}
}
but in IOS6, it doesn't. Do you get an error or exception? Or does everything run fine, but the print button is just not hidden? – psubsee2003