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 = 11111111232332;

    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 = 1;     //执行一次完整动画所需的时长
    self.imgView.animationRepeatCount = 0;  //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:0 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:0];
        // 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 1460.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];
}