IOS开发基础知识--碎片39
1:UIWindow知識(shí)點(diǎn)
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {self.window=[[UIWindow alloc]initWithFrame:[[UIScreen mainScreen]bounds]];self.window.backgroundColor=[UIColor redColor];self.window.rootViewController=[[ViewController alloc]init];[self.window makeKeyAndVisible];return YES;}iOS9要求所有UIWindow都有rootViewController,如果沒(méi)有rootViewController就會(huì)報(bào)錯(cuò)了;
(a)【self.window makekeyandvisible】讓窗口成為主窗口,并且顯示出來(lái)。有這個(gè)方法,才能把信息顯示到屏幕上。
(b) 因?yàn)閃indow有makekeyandvisible這個(gè)方法,可以讓這個(gè)Window憑空的顯示出來(lái),而其他的view沒(méi)有這個(gè)方法,所以它只能依賴(lài)于Window,Window顯示出來(lái)后,view才依附在Window上顯示出來(lái)。
(c)【self.window make keywindow】//讓uiwindow成為主窗口,但不顯示。
(d)[UIApplication sharedApplication].windows ?在本應(yīng)用中打開(kāi)的UIWindow列表,這樣就可以接觸應(yīng)用中的任何一個(gè)UIView對(duì)象(平時(shí)輸入文字彈出的鍵盤(pán),就處在一個(gè)新的UIWindow中)
(d)[UIApplication sharedApplication].keyWindow(獲取應(yīng)用程序的主窗口)用來(lái)接收鍵盤(pán)以及非觸摸類(lèi)的消息事件的UIWindow,而且程序中每個(gè)時(shí)刻只能有一個(gè)UIWindow是keyWindow。
提示:如果某個(gè)UIWindow內(nèi)部的文本框不能輸入文字,可能是因?yàn)檫@個(gè)UIWindow不是keyWindow
(f)view.window獲得某個(gè)UIView所在的UIWindow
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2:UINavigationController知識(shí)點(diǎn)
a.把子控制器添加到導(dǎo)航控制器中的四種方法
第一種:
?1.創(chuàng)建一個(gè)導(dǎo)航控制器
? ? UINavigationController *nav=[[UINavigationControlleralloc]init];
2.設(shè)置導(dǎo)航控制器為window的根視圖
? ? self.window.rootViewController=nav;
3.添加
? ? YYOneViewController ?*one = [[YYOneViewController ?alloc] init];
? ? [nav pushViewController:one animated:YES];
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第二種:
?1.創(chuàng)建一個(gè)導(dǎo)航控制器
?UINavigationController *nav=[[UINavigationControlleralloc]init];
?2.設(shè)置導(dǎo)航控制器為window的根視圖
?self.window.rootViewController=nav;
?3.添加
YYOneViewController ?*one = [[YYOneViewController ?alloc] init];
?[nav addChildViewController:one];
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第三種:
?1.創(chuàng)建一個(gè)導(dǎo)航控制器
?UINavigationController *nav=[[UINavigationControlleralloc]init];
?2.設(shè)置導(dǎo)航控制器為window的根視圖
?self.window.rootViewController=nav;
3.添加
YYOneViewController ?*one = [[YYOneViewController ?alloc] init];
nav.viewControllers=@[one];(添加到導(dǎo)航控制器的棧中)
說(shuō)明:nav.viewControllers;== nav.childViewControllers;注意該屬性是只讀的,因此不能像下面這樣寫(xiě)。nav.childViewControllers = @[one];
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第四種:最常用的方法
?YYOneViewController *one=[[YYOneViewController alloc]init];
?UINavigationController *nav=[[UINavigationController alloc]initWithRootViewController:one];
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b.當(dāng)前子控制器界面導(dǎo)航欄的標(biāo)題以及對(duì)應(yīng)返回標(biāo)題的設(shè)置
self.navigationItem.title=@"第一個(gè)界面";
self.navigationItem.backBarButtonItem=[[UIBarButtonItemalloc]initWithTitle:@"返回一" style:UIBarButtonItemStylePlain target:nilaction:nil];
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c.給導(dǎo)航欄添加按鈕
說(shuō)明:可添加一個(gè),也可以添加多個(gè)(數(shù)組)
添加導(dǎo)航欄左邊的按鈕(添加一個(gè)相機(jī)圖標(biāo)的按鈕),會(huì)蓋掉返回
?self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemCamera target:nil action:nil];
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d.界面跳轉(zhuǎn)
跳轉(zhuǎn)到第二個(gè)界面(當(dāng)前為第三個(gè),移除當(dāng)前棧頂?shù)目刂破?
?[self.navigationController popViewControllerAnimated:YES];
?移除處理?xiàng)5卓刂破髦獾乃锌刂破?
?[self.navigationController popToRootViewControllerAnimated:YES];
只要傳入棧中的某一個(gè)控制器,就會(huì)跳轉(zhuǎn)到指定控制器 [self.navigationController popToViewController:<#(UIViewController *)#> animated:<#(BOOL)#>];
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說(shuō)明:
導(dǎo)航控制器是通過(guò)棧的形式來(lái)管理子控制器的(先進(jìn)后出),顯示在導(dǎo)航控制器上得view永遠(yuǎn)是棧頂控制器的view,一個(gè)導(dǎo)航控制器只有一個(gè)導(dǎo)航條,也就是說(shuō)所有的自控制器公用一個(gè)導(dǎo)航條。
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附:打印當(dāng)前window下面的所有子控件,并通過(guò)xml文件來(lái)保存
// 應(yīng)用程序獲取焦點(diǎn)(代表著可以和用戶(hù)交互) - (void)applicationDidBecomeActive:(UIApplication *)application {NSLog(@"applicationDidBecomeActive");UINavigationController *nav = (UINavigationController *)self.window.rootViewController;UINavigationBar *bar = nav.navigationBar; // NSLog(@"%@", NSStringFromCGRect(bar.frame)); NSString *str = [self digView:self.window];[str writeToFile:@"/Users/apple/Desktop/ios6.xml" atomically:YES];}/*** 返回傳入veiw的所有層級(jí)結(jié)構(gòu)** @param view 需要獲取層級(jí)結(jié)構(gòu)的view** @return 字符串*/ - (NSString *)digView:(UIView *)view {if ([view isKindOfClass:[UITableViewCell class]]) return @"";// 1.初始化NSMutableString *xml = [NSMutableString string];// 2.標(biāo)簽開(kāi)頭[xml appendFormat:@"<%@ frame=\"%@\"", view.class, NSStringFromCGRect(view.frame)];if (!CGPointEqualToPoint(view.bounds.origin, CGPointZero)) {[xml appendFormat:@" bounds=\"%@\"", NSStringFromCGRect(view.bounds)];}if ([view isKindOfClass:[UIScrollView class]]) {UIScrollView *scroll = (UIScrollView *)view;if (!UIEdgeInsetsEqualToEdgeInsets(UIEdgeInsetsZero, scroll.contentInset)) {[xml appendFormat:@" contentInset=\"%@\"", NSStringFromUIEdgeInsets(scroll.contentInset)];}}// 3.判斷是否要結(jié)束if (view.subviews.count == 0) {[xml appendString:@" />"];return xml;} else {[xml appendString:@">"];}// 4.遍歷所有的子控件for (UIView *child in view.subviews) {NSString *childXml = [self digView:child];[xml appendString:childXml];}// 5.標(biāo)簽結(jié)尾[xml appendFormat:@"</%@>", view.class];return xml; }?
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3:UICollectionViewLayout自定義知識(shí)點(diǎn)
a:首先查看其開(kāi)放的屬性及方法,可以使用屬性對(duì)應(yīng)其方法,方法會(huì)比較靈活
@protocol UICollectionViewDelegateFlowLayout <UICollectionViewDelegate>@optional- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath;- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section;- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section;- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section;- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section;- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section;@endNS_CLASS_AVAILABLE_IOS(6_0) @interface UICollectionViewFlowLayout : UICollectionViewLayout@property (nonatomic) CGFloat minimumLineSpacing;@property (nonatomic) CGFloat minimumInteritemSpacing;@property (nonatomic) CGSize itemSize;@property (nonatomic) CGSize estimatedItemSize NS_AVAILABLE_IOS(8_0); // defaults to CGSizeZero - setting a non-zero size enables cells that self-size via -preferredLayoutAttributesFittingAttributes: @property (nonatomic) UICollectionViewScrollDirection scrollDirection; // default is UICollectionViewScrollDirectionVertical @property (nonatomic) CGSize headerReferenceSize;@property (nonatomic) CGSize footerReferenceSize;@property (nonatomic) UIEdgeInsets sectionInset;// Set these properties to YES to get headers that pin to the top of the screen and footers that pin to the bottom while scrolling (similar to UITableView). @property (nonatomic) BOOL sectionHeadersPinToVisibleBounds NS_AVAILABLE_IOS(9_0);@property (nonatomic) BOOL sectionFootersPinToVisibleBounds NS_AVAILABLE_IOS(9_0);@end?
b:Item size(每個(gè)item的大小),可以靈活定義到每個(gè)Item的大小
layout.itemSize = CGSizeMake(30,20);
或
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath;
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c:Line spacing(每行的間距)
@property (CGFloat) minimumLineSpacing
或
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section;
注意:這邊設(shè)置為其小的每行間距,實(shí)際如果大于這個(gè)間距就以自個(gè)為準(zhǔn);
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d:Inter cell spacing(每行內(nèi)部cell item的間距)
@property (CGFloat) minimum?InteritemSpacing
或
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section;
注意:同樣設(shè)置為最小的間距,實(shí)際如果比這個(gè)大則以自個(gè)為準(zhǔn)
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e:Scrolling direction(滾動(dòng)方向)
設(shè)置scrollDirection屬性即可。兩個(gè)值如下
UICollectionViewScrollDirectionVertical
UICollectionViewScrollDirectionHorizontal
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f:Header and footer size(頁(yè)眉和頁(yè)腳大小)
下面是頁(yè)眉和頁(yè)腳的一些解釋。
n 也就是supplementary views
n 通過(guò)數(shù)據(jù)源的方法來(lái)提供內(nèi)容,如下
- collectionView:viewForSupplementaryElementOfKind:atIndexPath:
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n 兩種常量(類(lèi)型)
UICollectionElementKindSectionHeader
UICollectionElementKindSectionFooter
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n 同樣需要注冊(cè)一個(gè)類(lèi)并從隊(duì)列中取出view
- registerClass:forSupplementaryViewOfKind:withReuseIdentifier:
- registerNib:forSupplementaryViewOfKind:withReuseIdentifier:
- dequeueReusableSupplementaryViewOfKind:withReuseIdentifier:forIndexPath:
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頁(yè)眉和頁(yè)腳的size配置方式:
1)可以全局配置,如下屬性
@property (CGSize) headerReferenceSize
@property (CGSize) footerReferenceSize
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2)也可以通過(guò)delegate對(duì)每一個(gè)section進(jìn)行配置,如下代碼
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section;
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section;
當(dāng)垂直的時(shí)候,需要設(shè)置Height,當(dāng)水平的時(shí)候,需要設(shè)置Width
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g:Section Inset(Section Inset就是某個(gè)section中cell的邊界范圍)
@property UIEdgeInsets sectionInset;
或
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section;
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運(yùn)用時(shí):
UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];self.mediaView = [[UICustomCollectionView alloc] initWithFrame:CGRectMake(10, 10, Main_Screen_Width-2*15, 80) collectionViewLayout:layout];?
4:模擬器改為Ipad?userInterfaceIdiom沒(méi)有效果的解決方法?
將模擬器改為Ipad時(shí),調(diào)用[[UIDevice currentDevice] userInterfaceIdiom]==UIUserInterfaceIdiomPad判斷設(shè)備是否為Ipad,但程序并未做出正確的判斷,后來(lái)做出如下設(shè)置:
PROJECT->Build Settings->Deployment->Targeted Device Family->iPhone/iPad
再次調(diào)試程序,成功識(shí)別出設(shè)備
轉(zhuǎn)載于:https://www.cnblogs.com/wujy/p/5481622.html
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