iPhone开发之启动画面及动画

一、静态图片的设置

iOS设备现在有三种不同的分辨率：iPhone 320x480、iPhone 4 640x960、iPad 768x1024。以前程序的启动画面(图片)只要准备一个 Default.png 就可以了，但是现在变得复杂多了。下面就是 CocoaChina 会员做得总结

如果一个程序，既支持iPhone又支持iPad，那么它需要包含下面几个图片：

Default-Portrait.png iPad专用竖向启动画面 768x1024或者768x1004

Default-Landscape.png iPad专用横向启动画面 1024x768或者1024x748

Default-PortraitUpsideDown.png iPad专用竖向启动画面(Home按钮在屏幕上面)，可省略 768x1024或者768x1004

Default-LandscapeLeft.png iPad专用横向启动画面，可省略 1024x768或者1024x748

Default-LandscapeRight.png iPad专用横向启动画面，可省略 1024x768或者1024x748

Default.png iPhone默认启动图片，如果没有提供上面几个iPad专用启动图片，则在iPad上运行时也使用Default.png（不推荐） 320x480或者320x460

Default@2x.png iPhone4启动图片640x960或者640x920

为了在iPad上使用上述的启动画面，你还需要在info.plist中加入key: UISupportedInterfaceOrientations。同时，加入值UIInterfaceOrientationPortrait, UIInterfacOrientationPortraitUpsideDown, UIInterfaceOrientationLandscapeLeft, UIInterfaceOrientationLandscapeRight。

二、设置静态图片停留的时间

在- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions中使用下面集中方法都可以：

1、sleep(3);

2、[NSThread sleepForTimeInterval:5.0];

3、[selfperformSelector:@selector(startupview) withObject:nilafterDelay:3];

三、设置启动动画

在appDelegate中加载启动动画的controller，在开启动画的controller中载入首页controller，通过透明度来设置淡入和淡出。

appDelegate.h

#import <UIKit/UIKit.h>
#import "Startupscreen.h"

@interface AppDelegate : UIResponder <UIApplicationDelegate> {
Startupscreen *startupscreen;
}

@property (strong, nonatomic) UIWindow *window;
@property (nonatomic, retain) Startupscreen *startupscreen;

@end

appDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
NSLog(@"didFinishLaunchingWithOptions");
self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
startupscreen = [[Startupscreen alloc] initWithNibName:@"Startupscreen" bundle:nil];
[self.window addSubview:startupscreen.view];
[self.window makeKeyAndVisible];
return YES;
}

Startupscreen.h

#import <UIKit/UIKit.h>
#import "ViewController.h"

@interface Startupscreen : UIViewController{

NSTimer *timer;
UIImageView *splashImageView;
UINavigationController *nav;
ViewController *myviewcontroller;
}

@property (nonatomic,retain) NSTimer *timer;
@property (nonatomic,retain) UIImageView *splashImageView;
@property (nonatomic,retain) UINavigationController *nav;
@property (nonatomic,retain) ViewController *myviewcontroller;

@end

Startupscreen.m

#import "Startupscreen.h"
#import "ViewController.h"

@interface Startupscreen ()

@end

@implementation Startupscreen
@synthesize timer;
@synthesize splashImageView;
@synthesize nav;
@synthesize myviewcontroller;

int flag;
NSTimer *timer;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
CGRect appFrame = [[UIScreen mainScreen] applicationFrame];
UIView *view = [[UIView alloc] initWithFrame:appFrame];
view.autoresizingMask = UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth;
self.view = view;
[view release];

flag = 0;

splashImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"c618Default1.png"]];
splashImageView.frame = CGRectMake(0, 0, 768, 1004);
[self.view addSubview:splashImageView];

timer = [NSTimer scheduledTimerWithTimeInterval:0.6
target:self
selector:@selector(addLabel)
userInfo:nil
repeats:YES];

myviewcontroller = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
myviewcontroller.view.alpha = 0.0;
//[self.view addSubview:myviewcontroller.view];
nav = [[UINavigationController alloc] init];
[nav pushViewController:myviewcontroller animated:NO];
[self.view addSubview:nav.view];

timer = [NSTimer scheduledTimerWithTimeInterval:3.0 target:self selector:@selector(fadeScreen) userInfo:nil repeats:NO];

}

- (void)addLabel{

flag++;
if (flag <=5) {
UILabel *label1 = [[UILabel alloc] initWithFrame:CGRectMake(200+50*flag,600,40, 40)];
label1.text = @"123";
label1.font = [UIFont systemFontOfSize:23];
label1.textColor = [UIColor whiteColor];
[self.view addSubview:label1];
[label1 release];
}

}

- (void)fadeScreen
{
[UIView beginAnimations:nil context:nil]; // begins animation block
[UIView setAnimationDuration:0.75];        // sets animation duration
[UIView setAnimationDelegate:self];        // sets delegate for this block
[UIView setAnimationDidStopSelector:@selector(finishedFading)];   // calls the finishedFading method when the animation is done (or done fading out)
self.view.alpha = 0.0;       // Fades the alpha channel of this view to "0.0" over the animationDuration of "0.75" seconds
[UIView commitAnimations];   // commits the animation block.  This Block is done.
}

- (void) finishedFading
{

[UIView beginAnimations:nil context:nil]; // begins animation block
[UIView setAnimationDuration:0.75];        // sets animation duration
self.view.alpha = 1.0;   // fades the view to 1.0 alpha over 0.75 seconds
myviewcontroller.view.alpha = 1.0;
[UIView commitAnimations];   // commits the animation block.  This Block is done.

for(UIView *mylabelview in [self.view subviews])
{
if ([mylabelview isKindOfClass:[UILabel class]]) {
[mylabelview removeFromSuperview];
}
}

[splashImageView removeFromSuperview];
}

上述代码实现了一个简单的进度启动动画，供大家参考。