Grant Technology

iCycle Period Logging and Prediction Free

2010-12-14T05:49:00.000-08:00

Free iPhone app iCycle Period Logging and Prediction Free is released. Get it from App Store.

The URL for Apps and Artists in App Store

2010-12-10T08:02:00.000-08:00

Examples:

http://itunes.com/XuanChen (for computer and iphone)
itms://itunes.com/XuanChen (for iphone only, only one redirection)
http://itunes.com/apps/XuanChen/MassageMap3D
itms://itunes.com/apps/XuanChen/MassageMap3D

More info:
http://developer.apple.com/library/ios/#qa/qa2008/qa1633.html

How to Hide Status Bar or Change Its Style in iPhone App

2010-12-07T21:38:00.000-08:00

By default, the status bar is displayed in iPhone App. If your root view frame origin is (0,0), it will be displayed just below the status bar.

If you want to hide the status bar, add one entry to the property list of your app:

Status bar is initially hidden

and make sure it is checked.

If you want to change the style of the status bar, add one entry to the property list:

Status bar style

Do not try to change status bar style or hide it in Interface Builder. That is only for visualizing other views or controls, not really changing the status bar.

Error: unrecognized selector sent to instance

2010-12-04T23:13:00.000-08:00

The error means an object does not respond to a selector sent to it. Various reasons can cause this error. Today I found another one: assigning to instance variable in class method can corrupt an object and cause it not to respond to a selector which it should.

For example, you have a view controller vc. By all means you expect [vc.view addSubview:anotherView] should work but you got error:

(null): unrecognized selector sent to instance 0xblah

Then you found that this view controller has a class method which updates some instance variables. Since it worked before, you think it is OK to do that. However, after some other coding, the application was suddenly broken, and you got that error. You can still NSLog(@"%@",vc.view) and it seems to be fine, but when you check [vc.view respondsToSelector:@selector(addSubview:)] you get NO.

This is totally insane. Then you noticed the compiler output:

warning: instance variable 'adView' accessed in class method

Then you remember you did something dubious: modifying instance variable in class method. In C++ such code won't compile but in objective-c it is just a warning.

After fixing this, the error disappeared.

The lessons learned:
1. Do not access instance variables in class method. Even if it works today, it may break tomorrow.
2. Pay attention to warnings. They said bad C++ code is like bullets which can shoot your toe. I would say objective-c is even worse.

UIViewController viewWillAppear not called

2010-11-29T23:23:00.000-08:00

If you add the view of a UITabBarController as subview to another view controller. When you tap the tab bar to swap in a new view, viewWillAppear of that view's controller will not be called. This causes problem because many times you use viewWillAppear to refresh a view managed by UITabBarController.

One workaround is to subclass UIView for the view you want to update, and move the stuff from viewWillAppear to drawRect.

The Simplest Way to Add iAd Banner to Your iPhone Application

2010-11-27T15:29:00.000-08:00

It is a bad idea to modify each view controller to add iAd banner. The simplest way to do that is to create a new root view controller and add an AdBannerView and your old root view to it. Do it in your application delegate:

ADBannerView *adView = [[ADBannerView alloc] initWithFrame:CGRectZero];

adView.currentContentSizeIdentifier = ADBannerContentSizeIdentifier320x50;

adView.frame=CGRectMake(0, 0, 320, 50);

AdVC* rootVC = [[AdVC alloc] initWithNibName:@"AdVC" bundle:nil];

[window addSubview:rootVC.view];

[rootVC.view addSubview:oldRootVC.view];

[rootVC.view addSubview:adView];

rootVC.view.frame = window.screen.applicationFrame;

oldRootVC.view.frame=CGRectMake(0, 50, 320, 480-50-20);

This will add a banner to all of your views, and it also allows you to easily remove the banner if the user choose to upgrade.

How to fix status bar covering UIView

2010-11-27T15:18:00.000-08:00

Sometime it is annoying that the status bar covers your UIView, and there are various other problems about the view location.

A simple fix is

rootVC.view.frame = window.screen.applicationFrame;

Xcode error: No launchable executable present at path

2010-11-27T06:29:00.000-08:00

If this error shows up after the name of the executable changes in Xcode, restarting Xcode could solve this problem.

Cocos2d v0.99.5-rc1 not working with Xcode 3.2.4

2010-11-22T22:17:00.000-08:00

There are lots of compilation errors using the default project file of cocos2d v0.99.5-rc1 with Xcode 3.2.4.

Use gcc or llvm-gcc instead of llvm, then it is OK.

How to Enter Copyright Symbol in Inkscape

2010-11-22T18:07:00.000-08:00

When inputing text, press Control to enter Unicode, then enter 00a9 for copyright symbol.

Massage Map 3D is ready for sale in iPhone App Store.

2010-11-15T18:21:00.000-08:00

Acupressure is a form of massage based on acupuncture points. Ancient Chinese found that stimulating special locations on the human body can relieve pain or ailments. These special locations are called acupuncture or acupressure points.

Massage Map 3D is the first software to provide an accurate and clear three dimensional map of all important acupressure points on human body. It is useful to people who are new to acupressure and also professional massage therapists.

The features include:

- Uses standard acupressure point code names based on authoritative acupressure and acupuncture books
- Includes both English and Chinese pinyin names for acupressure points
- Click an ailment to find the acupressure points that relieve it
- Ailments are organized by body parts or systems
- Browse acupressure points by code names
- The location of acupressure points are based on authoritative acupressure and acupuncture books
- The 3D human body can be rotated, moved and zoomed-in for better view of the acupressure points
- Includes detailed and professional instructions about how to locate the acupressure points
- Integrated with web search and wikipedia for images and webpages of acupressure points, anatomical and medical terms
- Includes basic instructions about how to locate acupressure points and perform acupressure

Massage Map 3D is now ready for sale in iPhone App Store.

Problem printing double with printf on iPhone

2010-11-14T20:41:00.000-08:00

On other platforms, it usually does not matter whether you use %g or %lg to print double with printf, but for iPhone, you have to use %lg.

sed for iphone

2010-11-13T11:58:00.000-08:00

Here is a simple sed for iphone using RegexKitLite:

// input - input string
// search - regex to search
// replace - string to replace with
// return value - output string

const char* sed(const char* input, const char* search,const char* replace) {

static char buf[100000]; // assume the output string length <100000

NSString *searchString = [NSString stringWithFormat:@"%s",input];

NSString *regexString = [NSString stringWithFormat:@"%s",search];

NSString *replaceWithString = [NSString stringWithFormat:@"%s",replace];

NSString *replacedString = NULL;

replacedString = [searchString stringByReplacingOccurrencesOfRegex:regexString withString:replaceWithString];

NSLog(@"replaced string: '%@'", replacedString);

strcpy(buf, [replacedString UTF8String]);

return buf;

}

sample usage:

char* buf = sed (str, "[ \\t]+", " "); // replace multiple white spaces with one space

// note you need double \\

To use it, you need to

1. download RegexKitLite

2. add RegexKitLite.h and RegexKitLite.m to your Xcode project

3. add libcucore.dylib to Frameworks of your Xcode project

Search the web for RegexKitLite:
For documentation of regex, see http://userguide.icu-project.org/strings/regexp