Multi-task requirements-iphone to meet user needs

Apple fans know that when the iphone 1.0 goes public, people feel sorry for the iphone's not supporting multitasking. Apple's explanation in HIG is that the screen is small, the memory is limited, and people can only interact with an application at one time.

Recently, I've been working on the Iphone-app project, and I've had some feelings about this multitasking.

First of all, what do people need to multitask?

• Quickly switch several applications.

As a http://www.aliyun.com/zixun/aggregation/3740.html ">iphone users, the installation of a large number of apps is just pediatrics, an inattentive, nine screens full." While the iphone's speed is excellent for running apps, it's important to be aware that time is more valuable in a mobile state, and that people will feel anxious if switching a program takes too much time. In the early days of HIG, the application response time should not exceed 20 seconds-please do not challenge people's psychological limits easily.

• Run two or more applications at the same time.

"Running at the same time" is said to be the main point----* * * * * * *. For example, while listening to music, playing games. While listening to the song, read it. Please do not challenge people's ability too much--watching movies while reading novels. People at the mobile end can use different senses to enjoy different services.

Even without multitasking, Apple's iphone 3G 3GS was as popular as the iphone iOS4.0. Why?

For the first requirement: quickly switch applications. Apple's solution is: 1. When the program exits, the user should retain the interface at this time, the system actively at any time for users to back up data (such as games, document editing, etc.) 2. Increase the speed of the hardware.

It can be said that the 3GS best-selling, is to meet a generation of users for the constant pursuit of speed.

For the second requirement: Run multiple programs at the same time. In Apple's view, you can listen to the ipod while doing other things, in principle, your service can not contain sound, otherwise the ipod will automatically pause until you quit other programs will automatically continue to play. So it can be said that Apple, considering the hardware features, temporarily does not have an open port.

In general, the needs of the user are met to some extent, conforming to the hardware constraints of the product at this stage. So when the iphone 4.0 comes in and makes a full multitasking experience, multitasking is not a simple thing to support, and they do a lot of meticulous work.

First, hardware performance metrics are fully upgraded-which makes multitasking possible. That's why the 3G model doesn't support it.

Second, increase interaction behavior. Double-click the home key to bring up the multiple taskbar. No matter which interface you can switch smoothly. Here, calling physical keys is the only option. Imagine that if you use gestures, the application developer lacks a gesture. Choosing home also makes multitasking management much more trustworthy and stable.

Finally, Apple gives a fairly detailed guideline to avoid many of the problems that multitasking poses:

Apple's demand for multitasking--in harmony with other applications in a multitasking environment--directs product designers to pay attention to the correct and controlled use of multitasking.

The following guidelines can help our applications better appear in a multitasking environment:

1. Interrupt or audio in the switch to transition nature.

2. Start or stop from the background, quickly and smoothly.

3. Running in the background is reliable enough.

To achieve these three points, you need to prepare as follows:

1. Always prepare the program to suspend or reboot. Because the multitasking feature increases the likelihood of users pausing an application. In addition, advertising and program switching will also allow more frequent pauses. Faster and more precise storage of the user's application state is a requirement for the application.

2. Ensure that your interface can accommodate twice times the height of the status bar. For example, when a phone comes, twice times the notification area of the status bar appears. In other words, your application cannot be problematic because of the presence of the notification area.

3. Allow users to suspend applications as they wish. The game for example, suspend the game application, when I come back, need to continue the game screen just now.

4. Make sure your audio service is appropriate. Multitasking allows media to continue service in the background. It also requires your audio service to pause or resume playback. To deal with this problem, you have to read the "Voice" section of the guide-users want to use the audio service you provide, but do not need to surprise and your special handling of the sound-for example, notify the reminder sound, bell tone. That will only create confusion-Apple will not apply to your app.

5. Use local notification push service. A program needs to be ready to suspend notifications for any time. With a local push notification, you need to read the relevant guidance document--Don't push all notifications--your users will crash because of meaningless notifications you push. (General should be: message arrival; event occurrence; new data request download; ）

6. When appropriate, in the background to complete the user's task. When people start a task, they want it done even if they switch to another application. So, if your program provides a task like this, and this kind of task does not require people to continue to pay attention, then the program should be silently completed in the background, the completion of a prompt to the user.

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User needs accompanied by the emergence of products and growth, targeted to meet user needs, just like Apple in multitasking practices, will need to split, that is not to draw their own prison, nor to attack the enthusiasm of the user, such a practice is worth our learning, overnight to finish the U.S. products, can only bring heavy pressure on the project, and excessive costs.

Source Address: http://www.blueui.net/blog/?p=189