My goal is to view the content of the bottom page from the top of the other content page. In order to accomplish this, I used PushModalAsync to navigate and set the BackgroundColor property of the navigation page to Transparent. I can view the content on the bottom page on Android. However on the iOS platform, a black color is always displayed and I am unable to read the content of the bottom page. Why is the background color always black even when it is set to be transparent in PushModalAsync?
Note: The iOS platform displays a white screen when I change the navigation to PushAsync.
Expected Behavior:
Background color should not be black and it should be transparent when navigating using PushModalAsync
Actual Behavior:
Background color is always black even when the content page background color is set as transparent when navigating using PushModalAsync
Android Screenshot
iOS Screenshot
The issue reproducing sample is provided below:
DemoSample
If you want to do EXACTLY like that, it is not possible (it will require so much work that you can't expect someone to provide you the solution here).
On iOS that control (ViewController) is drawn that way in that presentation mode. So as long as you use that control and that mode it will work that way irrelevant if you use Xamarin or something else. As ViewControllers are most basic controls it is not realistic to replace them with something else. But you can replace presentation mode. In Xamarin.Forms you can do that this way:
<ContentPage ...
xmlns:ios="clr-namespace:Xamarin.Forms.PlatformConfiguration.iOSSpecific;assembly=Xamarin.Forms.Core"
ios:Page.ModalPresentationStyle="FormSheet">
...
</ContentPage>
This will result in somewhat different visual presentation but that is the only way to have one ViewController drawn over another without going into some deep customization that would require tons of code, especially on Xamarin.Forms.
You can also try some other values, but the default value will not work.
In iOS, the hierarchy is managed by the view controller. Each page has a separate view controller. A page consists of a window, a root view, and a subview. You cannot see the layout of the previous page by setting the background color to be transparent.
For more details, you can refer to the following documents:
User interface | Microsoft
The View Controller Hierarchy | Apple
Related
How do I get the new toolbar item style of OSX Yosemite?
I created a standard toolbar, but the buttons don't have that button-like look. Do I need to drag actual buttons to the toolbar to get this look?
What I have:
What I want (that round bezel and white background):
There are two types of items in toolbars, image items and view items. It looks like you have an image item. You seem to want a view item where the view is an NSButton configured as a round textured button. So, yes, you should drag actual buttons to the toolbar.
I would not attempt to control the button background. You should use the button as-is to get the default system appearance. Apple recommends using a PDF template image (all black with the alpha channel used to make the image). The button itself would not have a title/label. Rather that would be on the containing toolbar item.
It looks like you may have applied an internal blue "glow" or highlight to your image. Generally, you should not do that. Let the frameworks apply appropriate effects to the template image automatically based on the button state and shows-state-by mode.
Toolbars in the Human Interface Guidelines
Controls which are appropriate to use in the window frame (including the toolbar)
Designing images for toolbar buttons
Works just fine for my Cocoa app under Yosemite -
are you actually setting the template property for your icon images..?
From the NSImage docs:
The 'template' property is metadata that allows clients to be smarter
about image processing. An image should be marked as a template if it
is basic glpyh-like black and white art that is intended to be
processed into derived images for use on screen.
The preview window/multitasking switcher shows a weird behaviour in iOS 7.
Here is how it appears when I set this property for both apps.
self.navigationController.navigationBar.translucent = NO;
Now for the white app I commented the line.
Now when I run it again and go directly to the switcher, this is what I get:
If I run the app and then go to the home screen or any other app and then go to the switcher, this is what I get:
Is there any way to correct this problem while having translucent navbar?
Thanks.
I ran into this as well. Since you don't have any content under the translucent navigation bar (and/or tab bar or tool bar), it can sometimes appear black in the app switcher. I was using a collection view that was constrained to the top and bottom layout guides and so there was nothing behind the tab bar and navigation bar. When the app is in the foreground it looks correct because there must be some default background color applied by Apple (maybe on the UIWindow) so you don't see through to the springboard. This background color seems to be gone (or black) when in the app switcher causing it to look like that.
The problem goes away on view controllers that are set to extend under top and/or bottom bars:
self.edgesForExtendedLayout = UIRectEdgeTop | UIRectEdgeBottom;
or in Interface Builder:
If that doesn't fit you needs or you still have other view controllers that don't extend under top and bottom bars you will still get the black bars in the app switcher. The way I solved it was to set the UIWindow background color in my appDelegate.
self.window.backgroundColor = [UIColor whiteColor];
Instead of doing it in code, you can also do it via Storyboard.
In the navigation bar of your root navigation bar, make sure you turn off its translucency.
I reckon it's a simpler solution.
I am in the process of transitioning an app to iOS7. All of the views throughout the app have a 44px empty space at the bottom that appears to be for a bottom toolbar or something, but I am not trying to display a bottom toolbar. This space also exists on views that do have a bottom toolbar and the toolbar just shows directly above it.
The red space shown is actually a view behind the black view. No matter what size I set the frame of the black view to, the red space is always shown. I am also hiding the status bar in plist, so don't know if this is an artifact from that or if it has something to do with navigation bar as they are both normally 44px in height.
I have looked at the transitioning guide and haven't found anything that's worked. Any ideas to what could be causing this and how to fix?
UPDATE:
I have tried setting edgesForExtendedLayout = UIRectEdgeAll and extendedLayoutIncludesOpaqueBars = YES (also tried NO) with no effect. When I look at the subviews of the navigation controller it shows a UIToolBar as hidden, but shows it contains a frame in the exact area the view refuses to resize to even with autolayout constraints.
UPDATE 2:
This is actually a problem with ViewDeckController (https://github.com/Inferis/ViewDeck) and the way it sets it's center view bounds.
I believe it has to do with the UINavigationBar. Try toggling the following options in Storyboard and see if it solves the problem. Namely, the 'Extend Edges' options:
These options can also be set in code with the edgesForExtendedLayout and extendedLayoutIncludesOpaqueBars properties on UIViewController.
If you are transitioning to iOS 7, you should be using an Auto Layout constraint to anchor to the Bottom Layout guide. Control drag from your view to the Bottom Layout guide and choose Vertical Space from the popup menu.
Using frames in iOS 7 is harder and is the way of the past.
Auto Layout is hard to grasp at first, but it is very powerful once you get the feel.
This is actually a problem with third party library ViewDeckController (https://github.com/Inferis/ViewDeck) and the way it sets centerViewBounds for IIViewDeckControllerIntegrated. I was able to figure it out after changing to IIViewDeckControllerContained and seeing the view sized correctly.
In IIViewDeckController.m, just return self.referenceBounds for iOS7 like it does for IIViewDeckControllerContained.
This is my first mac application. I've written for iOS before and have been able to accomplish this same goal.
I'm trying to change the background color of a custom view. In the photo below, the two views are named view0 and view1.
Here's the code I'm trying to use to accomplish this (in the AppDelegate.m file):
- (IBAction)upPressed:(id)sender {
NSLog(#"upPressed");
self.view0.layer.backgroundColor = CGColorCreateGenericRGB(1, 0, 0, 1);
}
I'd like the color of view0 to turn red upon pressing the up button. The button click registers fine.
When I run the simulator, the views do not even show up.
Upon clicking the up button, nothing changes.
Why is this single line of code inadequate? In iOS, I was able to use a similar method of setting the background color of a view to simply make its color change.
Select the custom view and then select the 'Show View Effects Inspector' in the right pane (looks like 3 pieces of paper on top of each other in Utilities Window). Check the box next to Custom View under Core Animation Layer. This will enable the Core Animation for that view type.
I have a WebView that is working perfectly. When I scroll it (up or down) past it's content I see a white area "Behind" the web page. (had an image here, but couldn't post due to being new).
I would like to set the overscroll color to clear.
To be precise I have played with setting the WebView background to transparent, and that does not achieve the desired result. That makes the entire page clear to the background of my app. I only want to see the app background if the user has scrolled past the contents of the window.
Any ideas?
Try this:
yourwebviewname.opaque=NO;