iOS關於啟動頁自定義特殊處理

平常開發中對於啟動頁可能會有一些特別的要求，比如在啟動頁加動畫或加一些按鍵可以響應事件等，最近項目中要在啟動頁增加版本號，因為版本號是不斷的改變，所以要動態實現把它加到啟動頁上；在XCode上面配置的Launch Images Source或Launch Screen FIle(IOS8以上會優先調用這個作為啟動項)都是保存一張靜態圖片；

原理：

其實原理也是很簡單，啟動頁還是運用Launch Images Source的內容，然后在做一個視圖在最上層，視圖的背景用啟動項的那張圖，讓人誤以為還在啟動中，啟動頁加載完成后，就顯示這層視圖，在2秒后再把這層視圖刪除，產生一個過度的假啟動頁效果；而我們自定義的動作就可以在這層視圖上進行；下面將通過Coding.net的APP講解這個功能；

一：創建一個視圖EaseStartView

EaseStartView.h文件內容：

#import <UIKit/UIKit.h>

@interface EaseStartView : UIView
+ (instancetype)startView;

- (void)startAnimationWithCompletionBlock:(void(^)(EaseStartView *easeStartView))completionHandler;
@end

EaseStartView.m文件內容：

#import "EaseStartView.h"
#import <NYXImagesKit/NYXImagesKit.h>
#import "StartImagesManager.h"

@interface EaseStartView ()
@property (strong, nonatomic) UIImageView *bgImageView, *logoIconView;
@property (strong, nonatomic) UILabel *descriptionStrLabel;
@end

@implementation EaseStartView

+ (instancetype)startView{
    UIImage *logoIcon = [UIImage imageNamed:@"logo_coding_top"];
    StartImage *st = [[StartImagesManager shareManager] randomImage];
    return [[self alloc] initWithBgImage:st.image logoIcon:logoIcon descriptionStr:st.descriptionStr];
}

- (instancetype)initWithBgImage:(UIImage *)bgImage logoIcon:(UIImage *)logoIcon descriptionStr:(NSString *)descriptionStr{
    self = [super initWithFrame:kScreen_Bounds];
    if (self) {
        //add custom code
        UIColor *blackColor = [UIColor blackColor];
        self.backgroundColor = blackColor;
        
        _bgImageView = [[UIImageView alloc] initWithFrame:kScreen_Bounds];
        _bgImageView.contentMode = UIViewContentModeScaleAspectFill;
        _bgImageView.alpha = 0.0;
        [self addSubview:_bgImageView];
        
        [self addGradientLayerWithColors:@[(id)[blackColor colorWithAlphaComponent:0.4].CGColor, (id)[blackColor colorWithAlphaComponent:0.0].CGColor] locations:nil startPoint:CGPointMake(0.5, 0.0) endPoint:CGPointMake(0.5, 0.4)];

        _logoIconView = [[UIImageView alloc] init];
        _logoIconView.contentMode = UIViewContentModeScaleAspectFit;
        [self addSubview:_logoIconView];
        _descriptionStrLabel = [[UILabel alloc] init];
        _descriptionStrLabel.font = [UIFont systemFontOfSize:10];
        _descriptionStrLabel.textColor = [UIColor colorWithWhite:1.0 alpha:0.5];
        _descriptionStrLabel.textAlignment = NSTextAlignmentCenter;
        _descriptionStrLabel.alpha = 0.0;
        [self addSubview:_descriptionStrLabel];
        
        [_descriptionStrLabel mas_makeConstraints:^(MASConstraintMaker *make) {
            make.centerX.equalTo(@[self, _logoIconView]);
            make.height.mas_equalTo(10);
            make.bottom.equalTo(self.mas_bottom).offset(-15);
            make.left.equalTo(self.mas_left).offset(20);
            make.right.equalTo(self.mas_right).offset(-20);
        }];

        [_logoIconView mas_makeConstraints:^(MASConstraintMaker *make) {
            make.centerX.equalTo(self);
            make.top.mas_equalTo(kScreen_Height/7);
            make.width.mas_equalTo(kScreen_Width *2/3);
            make.height.mas_equalTo(kScreen_Width/4 *2/3);
        }];
        
        [self configWithBgImage:bgImage logoIcon:logoIcon descriptionStr:descriptionStr];
    }
    return self;
}

- (void)configWithBgImage:(UIImage *)bgImage logoIcon:(UIImage *)logoIcon descriptionStr:(NSString *)descriptionStr{
    bgImage = [bgImage scaleToSize:[_bgImageView doubleSizeOfFrame] usingMode:NYXResizeModeAspectFill];
    self.bgImageView.image = bgImage;
    self.logoIconView.image = logoIcon;
    self.descriptionStrLabel.text = descriptionStr;
    [self updateConstraintsIfNeeded];
}

- (void)startAnimationWithCompletionBlock:(void(^)(EaseStartView *easeStartView))completionHandler{
    [[UIApplication sharedApplication].keyWindow
 addSubview:self];
    [[UIApplication sharedApplication].keyWindow
 bringSubviewToFront:self];
    _bgImageView.alpha = 0.0;
    _descriptionStrLabel.alpha = 0.0;

    @weakify(self);
    [UIView animateWithDuration:2.0 animations:^{
        @strongify(self);
        self.bgImageView.alpha = 1.0;
        self.descriptionStrLabel.alpha = 1.0;
    } completion:^(BOOL finished) {
        [UIView animateWithDuration:0.6 delay:0.3 options:UIViewAnimationOptionCurveEaseIn animations:^{
            @strongify(self);
            [self setX:-kScreen_Width];
        } completion:^(BOOL finished) {
            @strongify(self);
            [self removeFromSuperview];
            if (completionHandler) {
                completionHandler(self);
            }
        }];
    }];
}

@end

其實本實例中最為關鍵的內容在方法startAnimationWithCompletionBlock里

    [[UIApplication sharedApplication].keyWindow addSubview:self];
    [[UIApplication sharedApplication].keyWindow bringSubviewToFront:self];

代碼就是把這個視圖設置成在最前的最上層，這樣就可以蓋住程序中的頁面；

    _bgImageView.alpha = 0.0;
    _descriptionStrLabel.alpha = 0.0;

這個是為了下面的動畫做准備，若是直接用背景圖可以把這兩個都設置成0.99這樣就不會有一閃的錯覺；

    @weakify(self);
    [UIView animateWithDuration:2.0 animations:^{
        @strongify(self);
        self.bgImageView.alpha = 1.0;
        self.descriptionStrLabel.alpha = 1.0;
    } completion:^(BOOL finished) {
        [UIView animateWithDuration:0.6 delay:0.3 options:UIViewAnimationOptionCurveEaseIn animations:^{
            @strongify(self);
            [self setX:-kScreen_Width];
        } completion:^(BOOL finished) {
            @strongify(self);
            [self removeFromSuperview];
            if (completionHandler) {
                completionHandler(self);
            }
        }];
    }];

這邊是動畫效果，時間設置為2秒，因為這邊第一個動畫完還有一個左移出啟動頁的效果；當動畫結束后就可以  [self removeFromSuperview];

二：調用啟動頁視圖

在AppDelegate中的didFinishLaunchingWithOptions進行調用；

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];
    
    //網絡
    [[AFNetworkActivityIndicatorManager sharedManager] setEnabled:YES];
    [[AFNetworkReachabilityManager sharedManager] startMonitoring];
    
    //設置導航條樣式
    [self customizeInterface];
    [[UIApplication sharedApplication] setStatusBarHidden:NO withAnimation:UIStatusBarAnimationFade];


    if ([Login isLogin]) {
        [self setupTabViewController];
    }else{
        [UIApplication sharedApplication].applicationIconBadgeNumber = 0;
        [self setupIntroductionViewController];
    }
    [self.window makeKeyAndVisible];
    [FunctionIntroManager showIntroPage];

    EaseStartView *startView = [EaseStartView startView];
    @weakify(self);
    [startView startAnimationWithCompletionBlock:^(EaseStartView *easeStartView) {
        @strongify(self);
        //可以做其它事情
    }];
    
    return YES;
}

注意，EaseStartView代碼的位置是要放在最后面，因為要讓它蓋在最上層，就要后面加載，這樣就可以蓋在登錄頁面上面或者主頁上；到這就已經可以成功啟動頁的效果；

三：下面實例為項目中用到的動態加載版本號到啟動頁上

#import "StartUpView.h"

@interface StartUpView()
@property (strong, nonatomic) UIImageView *bgImageView;
@property (strong, nonatomic) UILabel *descriptionStrLabel;
@end

@implementation StartUpView

+ (instancetype)startView
{
    UIImage *bgImage=kshamLaunchImage;
    return [[self alloc] initWithBgImage:bgImage];
}


- (instancetype)initWithBgImage:(UIImage *)bgImage
{
    self = [super initWithFrame:Main_Screen_Bounds];
    if (self) {
        
        _bgImageView = [[UIImageView alloc] initWithFrame:Main_Screen_Bounds];
        _bgImageView.contentMode = UIViewContentModeScaleAspectFill;
        _bgImageView.alpha = 0;
        _bgImageView.image=bgImage;
        [self addSubview:_bgImageView];
        
        _descriptionStrLabel = [[UILabel alloc] init];
        _descriptionStrLabel.font = [UIFont systemFontOfSize:15];
        _descriptionStrLabel.textColor = [UIColor blackColor];
        _descriptionStrLabel.textAlignment = NSTextAlignmentCenter;
        _descriptionStrLabel.alpha = 0;
        _descriptionStrLabel.text=[NSString stringWithFormat:@"版本號為:%@",appVersion];
        [self addSubview:_descriptionStrLabel];
        
        [_descriptionStrLabel mas_makeConstraints:^(MASConstraintMaker *make) {
            make.height.mas_equalTo(50);
            make.bottom.equalTo(self.mas_bottom).offset(-15);
            make.left.equalTo(self.mas_left).offset(20);
            make.right.equalTo(self.mas_right).offset(-20);
        }];
    }
    return self;
}

- (void)startAnimationWithCompletionBlock:(void(^)(StartUpView *easeStartView))completionHandler{
    [[UIApplication sharedApplication].keyWindow addSubview:self];
    [[UIApplication sharedApplication].keyWindow bringSubviewToFront:self];
    _bgImageView.alpha = 0.99;
    _descriptionStrLabel.alpha = 0.99;
    
    @weakify(self);
    [UIView animateWithDuration:2.0 animations:^{
        @strongify(self);
        self.bgImageView.alpha = 1.0;
        self.descriptionStrLabel.alpha = 1.0;
    } completion:^(BOOL finished) {
        [self removeFromSuperview];
        if (completionHandler) {
            completionHandler(self);
        }
    }];
}
@end

 

 

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