Tag Archives: xamarin.ios

Xamarin.Forms: Switching TabbedPage Tabs Programmatically

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Sometimes, your app uses tabs to separate different user activities. Sometimes, though, those activities aren’t completely independent. When that happens, you need an action in one tab to cause the user to switch to another tab. I’ll show you how to do that in code using Xamarin.Forms. In case you haven’t already started your tabs, we’ll start from the beginning. (Note: while the UI parts can be done quite well in XAML, this post will do it all in code.) First, Some Tabs Just in case you haven’t already made your Xamarin.Forms tab system, we’ll start there. This is as simple as using an instance of TabbedPage. Since we will want a little more control over things going forward, let’s create a subclass inheriting from it. public class MainTabbedPage : TabbedPage { public MainTabbedPage() { Children.Add(new somePage()); Children.Add(new someOtherPage()); } } You simply make this the MainPage in your App, now, and you get tabs. public class App : Application { public App() { MainPage = new MainTabbedPage(); } } If you run your app at this point, though, you’ll notice something fairly obvious missing from your tabs. No titles, no icons. In fact, on iOS, you can’t even tell… Continue reading →

Abusing UIKit for Gaming in Xamarin.iOS, Part 3: Playing Sounds

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This is the third in a [glacially-paced] series of Abusing UIKit blog posts giving some background on the development that want into producing Smudges, a simple game written entirely in Xamarin.iOS where fun shapes in various colors show up on the screen wherever a tap is detected. It was original created to give my two-year-old something fun to play while going tap-crazy on the screen. The game evolved from those “play-testing” sessions. If you have your own little ones and want something fun to distract them, Smudges is availabe on the App Store. At this point, I plan to continue adding features to it as I can. Let me know what you think about Smudges, or these blog posts, in the comments below or find @patridgedev on Twitter. Let There Be Noise! Playing sounds in your apps can make for some great user interactions. Of course, it can also be used for far more annoying uses. For Smudges, each time an icon is placed on the screen with a tap, a random sound is played from a set of noises originally generated via as3sfxr (think Atari-era synth sounds). As a disclaimer, this will only cover playing the random sound here… Continue reading →

Abusing UIKit for Gaming in Xamarin.iOS, Part 2: Using Custom Fonts

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This is the second in a series of Abusing UIKit blog posts giving some background on the development that want into producing Smudges, a simple game written entirely in Xamarin.iOS where fun shapes in various colors show up on the screen wherever a tap is detected. It was original created to give my two-year-old something fun to play while going tap-crazy on the screen. The game evolved from those “play-testing” sessions. If you have your own little ones and want something fun to distract them, Smudges is availabe on the App Store. At this point, I plan to continue adding features to it as I can. Let me know what you think about Smudges, or these blog posts, in the comments below or find @patridgedev on Twitter. Using an Icon Font Using an icon font can be great for a typical app for substituting a mess of PNGs. For icons, the size savings is probably minimal, but dealing with a single font file compared to a folder of icon images in numerous DPI variations can be much nicer. Since we are dealing with “plain” text in a label, color is controlled by manipulating the label’s text color. For Smudges, the… Continue reading →

Abusing UIKit for Gaming in Xamarin.iOS, Part 1: Detecting Taps and Placing Views with UITapGestureRecognizer

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This is the first in a series of Abusing UIKit blog posts giving some background on the development that want into producing Smudges, a simple game written entirely in Xamarin.iOS where fun shapes in various colors show up on the screen wherever a tap is detected. It was original created to give my two-year-old something fun to play while going tap-crazy on the screen. The game evolved from those “play-testing” sessions. If you have your own little ones and want something fun to distract them, Smudges is availabe on the App Store. At this point, I plan to continue adding features to it as I can. Let me know what you think about Smudges, or these blog posts, in the comments below or find @patridgedev on Twitter. Where Did They Touch? Smudges has a simple game mechanic: tap the screen, new shape appears. The first step is figuring out when and where a tap occurred. The simple approach is to put a UIButton where you need to detect a touch, attaching a handler to its TouchUpInside event. UIButton someButton = new UIButton(someFrameRectangle); AddSubview(someButton); someButton.TouchUpInside += (sender, e) => { Debug.WriteLine(“Touched somewhere on this button.”); }; Of course, while incredibly simple,… Continue reading →

Capturing Your iOS App in Animated GIF Glory

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Showing the coolness of your iOS app in a web format can be very difficult, depending on what about your app makes it shine. If your app thrives on animation, especially the new UIKit Dynamics fun, you will need more than one frame to portray what your app does: enter the animated GIF, mother of all awesomeness. Here is the method I used to make the images for my Xamarin UIGravityBehavior recipe. That said, if you know a better way to do this, toss a comment out there; I’d love to hear about it. While I use these methods for my Xamarin.iOS creations, they apply equally to native apps and most anything running on a Mac. The Tool: LICEcap While the name sounds slightly…off, it definitely gets the job done. LICEcap, from Cockos Incorporated, is a quick disk image install. In fact, here’s LICEcap’s capture of me installing LICEcap. One thing to notice, these GIFs are not a great way to capture complex color palettes like the gradients in the install image folder. There may be a tool that is better at that, but you will probably compromise file size for fidelity. That install GIF was 81kb. Capturing the iOS… Continue reading →