我想创建一个具有非常灵活的图形用户界面(可换肤)的项目。为了实现这一点,我想从外部资源(例如网站)加载一个NSBundle。该bundle应包含与主项目中的某些属性和方法(IBOutlets和IBActions)相对应的nibs。
似乎苹果公司限制了使用NSBundle的可能性。是否有任何方法可以让这个工作?如果不能以传统的方式实现,有什么推荐的替代方案吗?
如承诺的一样,这里有一个简短的说明,介绍我是如何让它正常工作的。
在我的AppDelegate中,我检查服务器上是否有一个新的bundle(打包在zip文件中)。如果存在,我会下载bundle。该bundle包含我需要的可皮肤图形界面的nibs和其他相关数据(例如图形文件)。代码看起来有些像这样:
TestAppDelegate.m
- (void)downloadBundle
{
NSURL *url = [NSURL URLWithString:@"http://127.0.0.1/~wsc/template.bundle.zip"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSURLResponse *response = nil;
NSError *error = nil;
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
NSLog(@"%d", [httpResponse statusCode]);
if ([httpResponse statusCode] == 404) // bundle will be deleted and the default interface will be used ...
{
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"template.bundle"];
[[NSFileManager defaultManager] removeItemAtPath:path error:nil];
return;
}
else if (error)
{
NSLog(@"%@", error);
}
BOOL didWriteData = [data writeToFile:zipFile atomically:YES];
if (didWriteData)
{
BOOL success = [SSZipArchive unzipFileAtPath:zipFile toDestination:documentsDirectory];
if (!success)
{
NSLog(@"failed to unzip file.");
}
}
}
请注意,我使用了由neoneye建议的SSZipArchive类。需要将bundle打包到某种容器中以高效地下载所有内容,因为bundle只是遵循Apple约定的目录和文件结构。
我的其中一个类是一个具有标签和按钮作为IBOutlets的ViewController。 ViewController中最重要的代码如下:
TestViewController.h
@interface TestViewController : UIViewController {
UIButton *button;
UILabel *label;
}
@property (nonatomic, retain) IBOutlet UIButton *button;
@property (nonatomic, retain) IBOutlet UILabel *label;
- (IBAction)buttonTouched:(id)sender;
@end
TestViewController.m
@implementation TestViewController
@synthesize button, label;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
// the -init method is overridden to use nib file from bundle, if bundle exists ...
- (id)init
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *file = [documentsDirectory stringByAppendingPathComponent:@"template.bundle"];
NSBundle *bundle = [NSBundle bundleWithPath:file];
if (!bundle)
{
NSLog(@"no bundle found, falling back to default gui ...");
return [self initWithNibName:nil bundle:nil];
}
NSString *nibName = NSStringFromClass([self class]);
return [self initWithNibName:nibName bundle:bundle];
}
- (void)dealloc
{
[button release];
[label release];
[view release];
[super dealloc];
}
#pragma mark - View lifecycle
- (void)loadView
{
if (self.nibName && self.nibBundle)
{
// connect outlets to proxy objects ...
NSDictionary *objects = [NSDictionary dictionaryWithObjectsAndKeys:
self.label, @"label",
self.button, @"button",
nil];
NSDictionary *proxies = [NSDictionary dictionaryWithObject:objects forKey:UINibExternalObjects];
NSArray *nibs = [self.nibBundle loadNibNamed:self.nibName owner:self options:proxies]; // connection happens here ...
NSLog(@"nibs found with name %@: %d", self.nibName, [nibs count]);
return;
}
// show default gui if no nib was found ...
CGRect frame = [UIScreen mainScreen].applicationFrame;
self.view = [[[UIView alloc] initWithFrame:frame] autorelease];
[self.view setBackgroundColor:[UIColor lightGrayColor]];
self.button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[self.button setFrame:CGRectMake(0.0f, 0.0f, 60.0f, 30.0f)];
[self.button setCenter:CGPointMake(160.0f, 100.0f)];
[self.button addTarget:self action:@selector(buttonTouched:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:self.button];
self.label = [[[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 300.0f, 30.0f)] autorelease];
[self.label setCenter:CGPointMake(160.0f, 50.0f)];
[self.label setTextAlignment:UITextAlignmentCenter];
[self.view addSubview:self.label];
}
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad
{
[super viewDidLoad];
// for my purposes I'll add the localized string from the mainBundle here for the standard controls,
// this will override the text set in the nibs, since the nibs are loaded and displayed at this point ...
[self.button setTitle:NSLocalizedString(@"TestButton", nil) forState:UIControlStateNormal];
[self.label setText:NSLocalizedString(@"TestLabel", nil)];
}
- (void)viewDidUnload
{
[super viewDidUnload];
self.button = nil;
self.label = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark -
- (IBAction)buttonTouched:(id)sender
{
[[[[UIAlertView alloc] initWithTitle:NSLocalizedString(@"DialogTitle", nil)
message:NSLocalizedString(@"ButtonTouchedText", nil)
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil]
autorelease] show];
}
@end
实际的笔尖被定义在一个单独的链接项目中(Cocoa NSBundle 项目,有些参数被改变以使其适用于 iOS 设备)。文件的所有者是 TestViewController,所以我可以访问所有的插座和操作,并建立适当的连接。请注意,在 TestViewController 中没有定义 view (UIView *)属性,因为超类已经有了 view 属性。确保在界面构建器中连接视图。还要注意,nib 文件使用与实际类相同的名称以便使用。
在网上找不到太多关于如何做到这一点的信息,所以我希望这对于许多有类似目标的人都有所帮助。
未经测试。
您可以将所有内容打包成 zip 文件,使用 SSZipArchive 解压缩。
NSBundle* bundle = [NSBundle bundleWithPath:absolutePathToNibFile].
UIViewController* vc = [[[MyViewController alloc] initWithNibName:@"mycustomnib" bundle:bundle] autorelease];