iOS常用技术

0.科学上网

npm config set registry https://registry.npm.taobao.org --global
npm config set disturl https://npm.taobao.org/dist --global

1.判断系统

#define UMSYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)

调用方法:

UMSYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"8.0") //高于或等于 iOS8.0的系统

2.关于导航控制器下的高度 (以后整理)

iOS 7 :  viewDidLoad中   viewDidAppear:中

iOS 8及以后:viewDidLoad中   viewDidAppear:中

3.用逗号分隔一串数字

 - (void)formatMoney{

     NSInteger moneyNum = ;

     NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];

     formatter.numberStyle = NSNumberFormatterDecimalStyle;

     NSString* formatMoney = [formatter stringFromNumber:[NSNumber numberWithInteger:moneyNum]];

     NSLog(@"%@",formatMoney);

 }

4.nsdictionary的排序

         // 按等级从小到大排序

         NSArray *allKeys = [_dictLevelName allKeys];

         allKeys = [allKeys sortedArrayUsingComparator:^NSComparisonResult(id  _Nonnull obj1, id  _Nonnull obj2) {

             NSString *str1 = (NSString *)obj1;

             NSString *str2 = (NSString *)obj2;

             NSInteger level1 = [str1 integerValue];

             NSInteger level2 = [str2 integerValue];

             return [@(level1) compare:@(level2)];　　// compare:是NSNumber 的函数,不可以比较字符串,需要单独转换.

         }];

         for (NSString *key in allKeys) {

             NSString *name = [_dictLevelName objectForKey:key];

             if (ISSTRING(name)) {

                 [_arrayLevelName addObject:name];

             }

         }

5.NSAssert作用:若程序在此处崩溃,就能在不插入全局断点的情况下,崩在此处,代替全局断点的作用.

NSAssert(view, @"View must not be nil.");崩溃,倒退崩溃到了我的代码

[[PTVConfig instance] showToast:self.superview msg:@"解除屏蔽"];

是在 cell 中调用的,找不到父类 tableview 了,可见尽量少用 superview, 用父类作为代理直接处理.

6.查找最外层的控制器的方法:

UITabBarController *tabBar = (UITabBarController *)[[[[UIApplication sharedApplication] delegate] window] rootViewController];

UINavigationController *navi = tabBar.selectedViewController;

UIViewController *vc = navi.visibleViewController;

7.关于手势

• UITapGestureRecognizer
• UIPinchGestureRecognizer
• UIRotationGestureRecognizer
• UISwipeGestureRecognizer
• UIPanGestureRecognizer
• UILongPressGestureRecognizer

上面的手势对应的操作是：

• Tap（点一下）
• Pinch（二指往內或往外拨动，平时经常用到的缩放）
• Rotation（旋转）
• Swipe（滑动，快速移动）
• Pan （拖移，慢速移动）
• LongPress（长按）

8.运行 gif 图片,可以使用 UIImageView 动画. 代码如下:

 - (void)test {
     self.imgView.animationImages = [self animationImages]; //获取Gif图片列表
     self.imgView.animationDuration = ;     //执行一次完整动画所需的时长
     self.imgView.animationRepeatCount = ;  //动画重复次数
     [self.imgView startAnimating];
 }

 - (NSArray *)animationImages
 {
     NSFileManager *fielM = [NSFileManager defaultManager];
     NSString *path = [[NSBundle mainBundle] pathForResource:@"vip_new_comer_tail" ofType:@"bundle"];
     NSArray *arrays = [fielM contentsOfDirectoryAtPath:path error:nil];

     NSMutableArray *imagesArr = [NSMutableArray array];
     for (NSString *name in arrays) {
         NSString *imagePath = [path stringByAppendingPathComponent:name];
         NSData *data = [NSData dataWithContentsOfFile:imagePath];
         UIImage *image = [UIImage imageWithData:data];
         if (image) {
             [imagesArr addObject:image];
         }
     }
     return imagesArr;
 }

9.对于字符串形式保存的用户配置,若将其转换成字典,可以先使用方法将其转换成 NSData 对象,再将该对象装换成 NSDictionary 对象.

     NSString *conf = [dict objectForKey:@"conf"];
     if (conf) {
         NSData * data = [conf dataUsingEncoding:NSUTF8StringEncoding];
         if (data) {
            NSDictionary *confDict = [NSJSONSerialization JSONObjectWithData:data options: error:nil];
         }
     }

10.若给父视图添加了手势,则子视图UIControl 的点击事件被触发后,会先执行父视图的手势,后执行按钮的事件.

若想阻碍父视图的按钮事件,安静地执行按钮事件,可以在手势的delegate的代理方法中,查看当前用户点击的视图,来确定是否调用父视图的代理方法.

 - (void)viewDidLoad {
     [super viewDidLoad];
     [self setupUI];
 }

 - (void)setupUI{
     UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(onViewTouchDonw:)];
     recognizer.delegate = self;
     [self.view addGestureRecognizer:recognizer];

     [self.btn addTarget:self action:@selector(onBtnClick:) forControlEvents:UIControlEventTouchUpInside];
 }

 -(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
 {
     if([touch.view isKindOfClass:[UIButton class]])
     {
         NSLog(@"啦啦啦---%@",[touch.view class]);

         return NO;
     }
     return YES;
 }

11.判断麦克风和相机使用权限并打开的代码,iOS系统要在 plist 中添加信任的字符串,参考iOS 10 开发适配系列之权限Crash问题- 简书.

 /// 检查相机和麦克风的访问权限并提示设置
 - (BOOL)checkMediaTypeVideoAndAudio{
     BOOL bVideoAuthor = [self checkMediaTypeVideo];
     BOOL bAudioAuthor = [self checkMediaTypeAudio];

     if (bVideoAuthor && bAudioAuthor) {
         return YES;
     } else {
         return NO;
     }
 }

 /// 检查相机的访问权限并提示设置
 - (BOOL)checkMediaTypeVideo{
     __block BOOL bAuthor = NO;
     AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
     if (authStatus == AVAuthorizationStatusNotDetermined ||
         authStatus == AVAuthorizationStatusDenied ){

         // 首次访问照像机权限的时候会弹出允许或不允许的对话框,后来访问失败的话,会在以下 block 中传值为 NO 的参数
         [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
             if (!granted) {
                 UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:nil message:@"请在\"设置－隐私－相机\"选项中，允许熊猫直播访问你的相机" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil];
                 [alertView show];
             } else {
                 bAuthor = YES;
             }
         }];
     }
     return bAuthor;
 }

 /// 检查麦克风的访问权限并提示设置
 - (BOOL)checkMediaTypeAudio{
     __block BOOL bAuthor = NO;
     AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeAudio];
     if (authStatus == AVAuthorizationStatusNotDetermined ||
         authStatus == AVAuthorizationStatusDenied ) {

         // 首次访问麦克风权限的时候会弹出允许或不允许的对话框,后来访问失败的话,会在以下 block 中传值为 NO 的参数
         [AVCaptureDevice requestAccessForMediaType:AVMediaTypeAudio completionHandler:^(BOOL granted) {
             if (!granted) {
                 UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:nil message:@"请在\"设置－隐私－麦克风\"选项中，允许熊猫直播访问你的麦克风" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil];
                 [alertView show];
             }
         }];

     }
     return bAuthor;
 }

12.YYModel不同变量的使用方法

 + (NSDictionary *)modelCustomPropertyMapper {
     NSMutableDictionary *chatMappers = [@{@"text" : @"data.text",
                                   @"color" : @"data.color",
                                   @"size" : @"data.size",
                                   @"font" : @"data.font",
                                   } mutableCopy];
     NSDictionary *baseMappers = @{@"rid"  : @"from.rid",
                                   @"nick"  : @"from.nick",
                                   @"level"  : @"from.level",
                                   @"fromLevelMin"  : @"from.level_min",
                                   @"fromLevelMax"  : @"from.level_max",
                                   @"exp"  : @"from.exp",
                                   @"roleName"  : @"from.role_name",
                                   @"roleVal" : @"from.role_val",
                                   @"xroomId"  : @"to",
                                   @"type"  : @"type",
                                   };
     [chatMappers addEntriesFromDictionary:baseMappers];
     return chatMappers;
 }

13.YYText 在 cell 中时,获取点击的位置

 - (void)onTapChatMsg:(UITapGestureRecognizer *)tap{
     CGRect rect = self.chatMsgLabel.textLayout.textBoundingRect;
     CGPoint point = [tap locationInView:tap.view];
     if (CGRectContainsPoint(rect, point)) {
         NSLog(@"被点击了");
     }
 }

14.选中某个 cell 的常用代码:

 /// 某个 cell 是否被选中, 在 cellForItemAtIndexPath 代理方法中调用
 - (void)selectedCellIfNeeded:(PXYStickerCollectionViewCell *)cell indexPath:(NSIndexPath *)indexPath
 {
     if (self.lastSelectIndexPath == nil)
     {
         return;
     }
     if(indexPath.item == self.lastSelectIndexPath.item)
     {
         cell.backgroundColor = [UIColor colorWithRed:0.4 green:0.4 blue:0.4 alpha:0.4];
         cell.gradientLayer.hidden = YES;
     }
     else
     {
         cell.backgroundColor = [UIColor clearColor];
         cell.gradientLayer.hidden = NO;
     }
 }

 /// 选中某个 cell, 在 didSelectItemAtIndexPath 代理方法中调用
 - (void)selectingIndexPath:(NSIndexPath *)indexPath collectionView:(UICollectionView *)collectionView{

     PXYStickerCollectionViewCell *cell = (PXYStickerCollectionViewCell *)[collectionView cellForItemAtIndexPath:indexPath];
     cell.backgroundColor = [UIColor colorWithRed:0.4 green:0.4 blue:0.4 alpha:0.4];
     cell.gradientLayer.hidden = YES;

     if (self.lastSelectIndexPath == nil)
     {
         self.lastSelectIndexPath = indexPath;
         return;
     }
     else if (self.lastSelectIndexPath.item == indexPath.item)
     {
         return;
     }

     PXYStickerCollectionViewCell *lastCell = (PXYStickerCollectionViewCell *)[collectionView cellForItemAtIndexPath:self.lastSelectIndexPath];
     lastCell.backgroundColor = [UIColor clearColor];
     lastCell.gradientLayer.hidden = NO;
     self.lastSelectIndexPath = indexPath;
 }

15.限制输入多少个字符

 - (void)textViewDidChange:(UITextView *)textView{
     NSString *lang = [[UIApplication sharedApplication]textInputMode].primaryLanguage; // 键盘输入模式
     if ([lang isEqualToString:@"zh-Hans"]) { // 简体中文输入，包括简体拼音，健体五笔，简体手写
         UITextRange *selectedRange = [textView markedTextRange];
         //获取高亮部分
         UITextPosition *position = [textView positionFromPosition:selectedRange.start offset:];
         // 没有高亮选择的字，则对已输入的文字进行字数统计和限制
         if (!position) {
             [self checkTextViewText:textView];
         }
         // 有高亮选择的字符串，则暂不对文字进行统计和限制
         else{
             [self checkTextViewText:textView];
         }
     }
     // 中文输入法以外的直接对其统计限制即可，不考虑其他语种情况
     else{

     }
 }

 - (void)textViewDidEndEditing:(UITextView *)textView{
     [self checkTextViewText:textView];
 }

 - (void)checkTextViewText:(UITextView *)textView {
     if (textView.text.length > kMaxInputWindPlaneEditView) {
         textView.text = [textView.text substringToIndex:kMaxInputWindPlaneEditView];
         [[PTVConfig instance] showToast:self msg:[NSString stringWithFormat:@"文字长度不能超过%li个字符",(long)kMaxInputWindPlaneEditView]];
     }
 }

16.把崩溃日志转化为具体的某一行(crash 崩溃)(参考http://www.jianshu.com/p/da186c14db0f)

(/Users/liuzhu/Library/Developer/Xcode/DerivedData/xxx-atouolfjhjicfrgglhmhmicssual/Build/Products 中含有 dsym 文件)

 chmod +x symbolicatecrash
  export DEVELOPER_DIR="/Applications/XCode.app/Contents/Developer"
 ./symbolicatecrash .crash PandaTV-ios.app.dSYM > Control_symbol.crash

(PS:Xcode7.3 symbolicatecrash路径
/Applications/Xcode.app/Contents/SharedFrameworks/DVTFoundation.framework/Versions/A/Resources/symbolicatecrash)

17.在分类中添加属性,核心代码如下:

 #import <objc/runtime.h>
 @property (nonatomic,assign) CGFloat count;

 -(void)setCount:(CGFloat)count{
     objc_setAssociatedObject(self, @selector(count), @(count), OBJC_ASSOCIATION_RETAIN_NONATOMIC);
 }

 -(CGFloat)count{
     NSNumber *count = objc_getAssociatedObject(self, @selector(count));
     return count.floatValue;
 }

18.若 UIScrollView 的尺寸随着其中的图片尺寸在变化,则可以设置UIViewController中的automaticallyAdjustsScrollViewInsets属性来让其不变

 - (void)viewDidLoad {
     [super viewDidLoad];
     [self setAutomaticallyAdjustsScrollViewInsets:NO];
 }