iOS|iOS PSTAlertController 源码泛读 iOSPSTAlertController源码泛读

PSTAlertController 是为了能让用户从 iOS7开始兼容 UIAlertController
why UIAlertController?

iOS8 以后出的新类，目标就是为了替代 UIActionSheet
and UIAlertView
,接口也极其友好，容易创建，以controller的形式展示更方便点！

兼容iOS7 的痛苦，不能使用心得API 还好git上有这么多优秀的开源项目！

话说，为什么我们现在还要兼容iOS7呢？？

PSTAlertController 其实也没有什么特别的地方通过判断能不能使用 UIAlertController 来创建的

- (BOOL)alertControllerAvailable { return [UIAlertController class] != nil; // iOS 8 and later. }

以上就是判断创建的时候生成view的时候生成哪个

- (instancetype)initWithTitle:(NSString *)title message:(NSString *)message preferredStyle:(PSTAlertControllerStyle)preferredStyle { if ((self = [super init])) { _title = [title copy]; _message = [message copy]; _preferredStyle = preferredStyle; if ([self alertControllerAvailable]) { _alertController = [PSTExtendedAlertController alertControllerWithTitle:title message:message preferredStyle:(UIAlertControllerStyle)preferredStyle]; } else { #if __IPHONE_OS_VERSION_MIN_REQUIRED < 80000 if (preferredStyle == PSTAlertControllerStyleActionSheet) { _strongSheetStorage = [[UIActionSheet alloc] initWithTitle:title delegate:self cancelButtonTitle:nil destructiveButtonTitle:nil otherButtonTitles:nil]; } else { _strongSheetStorage = [[UIAlertView alloc] initWithTitle:title message:message delegate:self cancelButtonTitle:nil otherButtonTitles:nil]; } #endif } } return self; }

创建的时候再根据能不能使用UIAlertController和类型来创建
UIAlertController 或者 UIActionSheet 或者 UIAlertView

- (UIAlertView *)alertView { return (UIAlertView *)(self.strongSheetStorage ?: self.weakSheetStorage); }- (UIActionSheet *)actionSheet { return (UIActionSheet *)(self.strongSheetStorage ?: self.weakSheetStorage); }

获取alertView 或者 actionView

- (void)addAction:(PSTAlertAction *)action { NSAssert([action isKindOfClass:PSTAlertAction.class], @"Must be of type PSTAlertAction"); action.alertController = self; // weakly connectself.actions = [[NSArray arrayWithArray:self.actions] arrayByAddingObject:action]; if ([self alertControllerAvailable]) { __weak typeof (self) weakSelf = self; UIAlertAction *alertAction = [UIAlertAction actionWithTitle:action.title style:(UIAlertActionStyle)action.style handler:^(UIAlertAction *uiAction) { weakSelf.executedAlertAction = action; [action performAction]; }]; [self.alertController addAction:alertAction]; } else { if (self.preferredStyle == PSTAlertControllerStyleActionSheet) { NSUInteger currentButtonIndex = [self.actionSheet addButtonWithTitle:action.title]; if (action.style == PSTAlertActionStyleDestructive) { self.actionSheet.destructiveButtonIndex = currentButtonIndex; } else if (action.style == PSTAlertActionStyleCancel) { self.actionSheet.cancelButtonIndex = currentButtonIndex; } } else { NSUInteger currentButtonIndex = [self.alertView addButtonWithTitle:action.title]; // UIAlertView doesn't support destructive buttons. if (action.style == PSTAlertActionStyleCancel) { self.alertView.cancelButtonIndex = currentButtonIndex; } } } }

添加点击行为，也是根据 alertControllerAvailable 先判断是不是iOS8 以前的系统.如果不是，就调用 UIAlertView 或者 UIActionSheet的添加按钮的方式添加。

- (NSInteger)addButtonWithTitle:(nullable NSString *)title; // returns index of button. 0 based.

需要执行的block则保存在actions 数组中。如果是iOS8之前的系统，则会在UIAlertView或者UIActionSheet的代理中执行，比如：

- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex { [self viewWillDismissWithButtonIndex:buttonIndex]; }- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex { [self viewDidDismissWithButtonIndex:buttonIndex]; }

JCAlertController 一览
更加丰富的从iOS7开始支持的弹窗还有JCAlertController 详情见git地址。支持的样式更多，而且支持以一个队列的方式弹出。比如：
请看下面的伪代码:

[self presentWithFIFO:alert1]; [self presentWithFIFO:alert2]; [self presentWithFIFO:alert3];

结果:
alert1第一个显示, 被用户关闭后, alert2第二个显示, 被用户关闭后, alert3第三个显示
就像这样: alert1 >> alert2 >> alert3
JCAlertController的源码文件如下

|____.DS_Store |____AlertView | |____JCAlertView.h | |____JCAlertView.m |____ButtonItem | |____JCAlertButtonItem.h | |____JCAlertButtonItem.m |____Category | |____NSAttributedString+JCCalculateSize.h | |____NSAttributedString+JCCalculateSize.m | |____UIColor+JCHightlightedColor.h | |____UIColor+JCHightlightedColor.m | |____UIImage+JCColor2Image.h | |____UIImage+JCColor2Image.m | |____UIViewController+JCPresentQueue.h // present category | |____UIViewController+JCPresentQueue.m | |____UIWindow+JCBlur.h | |____UIWindow+JCBlur.m |____JCAlertController.h // import this |____JCAlertController.m |____Style | |____JCAlertStyle.h | |____JCAlertStyle.m | |____JCAlertStyleAlertView.h | |____JCAlertStyleAlertView.m | |____JCAlertStyleBackground.h | |____JCAlertStyleBackground.m | |____JCAlertStyleButton.h | |____JCAlertStyleButton.m | |____JCAlertStyleButtonCancel.h | |____JCAlertStyleButtonCancel.m | |____JCAlertStyleButtonNormal.h | |____JCAlertStyleButtonNormal.m | |____JCAlertStyleButtonWarning.h | |____JCAlertStyleButtonWarning.m | |____JCAlertStyleContent.h | |____JCAlertStyleContent.m | |____JCAlertStyleSeparator.h | |____JCAlertStyleSeparator.m | |____JCAlertStyleTitle.h | |____JCAlertStyleTitle.m

平时使用的时候，只要import JCAlertController即可！
JCAlertController 中定义了一些初始化和添加元素的方法。
同时定义了一个分类，是当有键盘事件的时候怎么处理。

@interface JCAlertController (keyboardHandle)

看看 JCAlertController的组成

@interface JCAlertController ()@property (nonatomic, strong) UIImageView *blurView; @property (nonatomic, strong) UIButton *coverView; @property (nonatomic, strong) JCAlertView *alertView; @end

一个有模糊样式的背景图片。一个可以接收点击的时间的遮挡按钮，然后就是看到的提示框 JCAlertView
然后定义了转场动画。

///消失的动画 @interface JCDimissAnimation : NSObject @end ///弹出的动画 @interface JCPresentAnimation : NSObject @end

用来展示提示框变化的过渡动画！

- (void)viewDidLoad { [super viewDidLoad]; ///设置背景模糊图片 [self setupBlurView]; ///添加点击按钮 [self setupAlphaCoverView]; ///根据整体Style设置alertView [self setupAlertView]; }

【iOS|iOS PSTAlertController 源码泛读】唯一不能满足的就是没有ActionSheet的样式