Join Garrick Chow for an in-depth discussion in this video Running apps and multitasking, part of iPhone and iPod touch iOS 4 Essential Training.
- View Offline
One of the most significant new features introduced with the release of the iOS 4 operating system was multitasking. Multitasking allows you to leave multiple applications running and quickly switch between them. This lets you do things like start playing games exactly where you left off, leave GPS applications running in the background or have music apps keep playing music while you perform other tasks on your device. Multitasking is available on the iPhone 3GS, the iPhone 4 and the second-generation iPod touch. Let's take a look at how it works. I have an app called Pandora installed on my phone. It's a popular streaming Internet music app.
So here on my iPhone running iOS 4, I can start some music playing, and once my music is playing, I can start doing other things on my phone while the music continues to play in the background. I will tab my Home button, and maybe now I want to work on some email. Or maybe I want to check the weather. As you can hear, Pandora continues to play music the entire time. Now so far, I have been switching between apps by pressing my Home button to return to the home screen and then tapping the app I want to run.
But another way is to use the Multitasking bar. You invoke multitasking by double- clicking the Home button, which opens the Multitasking bar at the bottom of the screen. Here, you will find the icons for all the apps you have most recently opened. Just tap an app to switch back to it. For example, I will tap Pandora, and I can see the status, or progress of the music that's currently playing, or in this case I will pause it. Or I can double-click again to go back to my mail and pick up right where I left off. What you will find is that all your most recent apps are going to appear in the Multitasking bar, and you can access them all by flicking the bar to the left to browse through them.
Multitasking also comes in handy when a call comes in, interrupting whatever important work you are working at the time. For example, let's say I am playing this game, and then a call comes in. Notice the game sort of gets visually shuffled back. I can answer the call, have my conversation, and when I hang up, the last app I was using, in this case the game, gets shuffled back to the front, exactly where I left off. Pretty cool! Now this doesn't mean that every single program here is running in the background and eating up processing and battery power.
First of all, apps have to be optimized by their creators to support multitasking, but many app creators have already implemented the support. Also, the apps listed here may still have to boot up from the beginning instead of where you left off, if you haven't opened them for a while. Your most recently used app should always pick up where you left off, though. Another use of the Multitasking bar is for quitting applications. Occasionally you will have an app that starts acting funny or not working properly, but since current apps are always running, you may have to force it to quit so you can reboot it. To do this, just hold down your finger on one the apps in the Multitasking bar until the icon start to wiggle.
Then tap the red Close icon on the app you're having problems with to quit it. You can then close the Multitasking bar and try starting up the app again by tapping its icon. The final features of the Multitasking bar I want to show you can be found by double-clicking the Home button to invoke multitasking and then flicking to the right, revealing music control buttons, which can control both your iPod music and certain enabled apps like Pandora when they are running. We will look at more of these controls in the chapter on using the iPod part of your phone, but this is also where you will find the orientation lock. Most applications are designed to rotate the displays when you rotate the phone.
For example, if I open Mail, I can read my mail in both portrait and landscape orientation. But sometimes you don't want the content of the apps to rotate. For example, if you like to read the iPhone in bed while lying on your side, you don't want the screen to rotate into landscape mode. So just double-click the Home button to open the Multitasking bar, flick to the right, and tap the Orientation Lock button, which locks all apps into portrait mode. Then close the Multitasking bar, and you will see the Orientation Lock icon at the top of your screen.
Now when I open mail and rotate the phone, the display remains in portrait mode. So that's how Multitasking works on the iPhone and iPod touch.
- Exploring the touchscreen interface
- Setting up iPhone and iPod Touch preferences
- Synching with a Mac or PC
- Typing with the intelligent keyboard
- Making phone calls and retrieving voicemail
- Finding a location with Maps
- Downloading and playing music and video
- Shooting photos and video
- Using accessibility features
- Locating a lost iPhone with MobileMe
- Finding and purchasing applications from the App Store