iOS小技能：下拉刷新控件的适配

#import <MJRefresh/MJRefresh.h>
@interface ERPMJRefreshNormalHeader4StyleWhite : MJRefreshNormalHeader

+ (instancetype)headerWithRefreshingTarget:(id)target refreshingAction:(SEL)action
{
    MJRefreshHeader *cmp = [[self alloc] init];
    
    [cmp setRefreshingTarget:target refreshingAction:action];
    [self setupStyleWhite:cmp];
    return cmp;
}

+(void)setupStyleWhite:(MJRefreshNormalHeader*)mj_header{
    
    
    mj_header.stateLabel.textColor = UIColor.whiteColor;
    mj_header.lastUpdatedTimeLabel.textColor=mj_header.stateLabel.textColor;
    mj_header.loadingView.activityIndicatorViewStyle =UIActivityIndicatorViewStyleWhite;
    
}

        ERPMJRefreshNormalHeader4StyleWhite *mj_header =[ERPMJRefreshNormalHeader4StyleWhite headerWithRefreshingTarget:self refreshingAction:@selector(headerRereshing)];        
        
        UIImage *bgImg = [UIImage getMaingradientColorImage];
        
        UIColor *tmpColor = [UIColor colorWithPatternImage:bgImg];
        
        mj_header.backgroundColor =tmpColor;
        
        [self setupStretchViewColor:mj_header.backgroundColor tableView:_vcView.tableView];
        
        _vcView.tableView.mj_header = mj_header;

        _vcView.tableView.bounces = YES;

- (void)setupStretchViewColor:(UIColor*) stretchViewColor tableView:(UIView*)tableView{
    

    [tableView addObserver:self forKeyPath:@"contentOffset" options:NSKeyValueObservingOptionOld|NSKeyValueObservingOptionNew context:nil];
    
    
    self.stretchView.backgroundColor =stretchViewColor;
    //往tableView的父控件添加拉伸背景视图
    [tableView.superview addSubview:self.stretchView];
    

}

#pragma mark - 拉顶部背景色
-(void)observeValueForKeyPath:(NSString*)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id>*)change context:(void*)context{
    if([keyPath isEqualToString:@"contentOffset"]){
        NSValue *value = change[NSKeyValueChangeNewKey];
        CGFloat chaneoffsetY = value.UIOffsetValue.vertical;
        UIView *mj_header= self.vcView.tableView.mj_header;
        
        self.stretchView.frame = CGRectMake(0,0,mj_header.width,-chaneoffsetY-mj_header.height);
    }
}

/**
 拉伸背景

 @return view
 */
-(UIView *)stretchView{
    
    if (!_stretchView) {
        
        UIView *tmp =[[UIView alloc] init];
        _stretchView =tmp;
//        _stretchView.backgroundColor = self.backgroundColor;
    }
    return _stretchView;
}

xxNavigationViewController *nav = [[xxNavigationViewController alloc] initWithRootViewController:loginViewController];
nav.modalPresentationStyle = UIModalPresentationFullScreen;
[self presentViewController:nav animated:YES completion:nil];
//推荐使用UIModalPresentationOverFullScreen

//
//  UIViewController+ERPPresent13.h

#import <UIKit/UIKit.h>
#import <objc/runtime.h>

NS_ASSUME_NONNULL_BEGIN

@interface UIViewController (ERPPresent13)

/**
Whether or not to set ModelPresentationStyle automatically for instance, Default is [Class K_automaticallySetModalPresentationStyle].
@return BOOL
*/
@property (nonatomic, assign) BOOL K_automaticallySetModalPresentationStyle;

/**
 Whether or not to set ModelPresentationStyle automatically, Default is YES, but UIImagePickerController/UIAlertController is NO.
 @return BOOL
 */
+ (BOOL)K_automaticallySetModalPresentationStyle;

@end

NS_ASSUME_NONNULL_END

//
//  UIViewController+ERPPresent13.m

#import "UIViewController+ERPPresent13.h"

static const char *K_automaticallySetModalPresentationStyleKey;

@implementation UIViewController (ERPPresent13)
+ (void)load {
    Method originAddObserverMethod = class_getInstanceMethod(self, @selector(presentViewController:animated:completion:));
    Method swizzledAddObserverMethod = class_getInstanceMethod(self, @selector(K_presentViewController:animated:completion:));
    method_exchangeImplementations(originAddObserverMethod, swizzledAddObserverMethod);
}

- (void)setK_automaticallySetModalPresentationStyle:(BOOL)K_automaticallySetModalPresentationStyle {
    objc_setAssociatedObject(self, K_automaticallySetModalPresentationStyleKey, @(K_automaticallySetModalPresentationStyle), OBJC_ASSOCIATION_ASSIGN);
}

- (BOOL)K_automaticallySetModalPresentationStyle {
    id obj = objc_getAssociatedObject(self, K_automaticallySetModalPresentationStyleKey);
    if (obj) {
        return [obj boolValue];
    }
    return [self.class K_automaticallySetModalPresentationStyle];
}

+ (BOOL)K_automaticallySetModalPresentationStyle {
    if ([self isKindOfClass:[UIImagePickerController class]] || [self isKindOfClass:[UIAlertController class]]) {
        return NO;
    }
    return YES;
}

- (void)K_presentViewController:(UIViewController *)viewControllerToPresent animated:(BOOL)flag completion:(void (^)(void))completion {
    if (@available(iOS 13.0, *)) {
        if (viewControllerToPresent.K_automaticallySetModalPresentationStyle) {
            viewControllerToPresent.modalPresentationStyle = UIModalPresentationFullScreen;
        }
        [self K_presentViewController:viewControllerToPresent animated:flag completion:completion];
    } else {
        // Fallback on earlier versions
        [self K_presentViewController:viewControllerToPresent animated:flag completion:completion];
    }
}

@end

    [self.vcView mas_makeConstraints:^(MASConstraintMaker *make) {
        
        make.left.equalTo(weakSelf.view).offset(0);
        make.right.equalTo(weakSelf.view).offset(- 0);
        make.top.equalTo(weakSelf.view).offset(0);
        if(isHasSafeAreaInsets()){// 避免没有上拉的时候加载更多控件的文案也显示出来了
            UIWindow *mainWindow = [[[UIApplication sharedApplication] delegate] window];
            CGFloat bottom = mainWindow.safeAreaInsets.bottom;
            make.bottom.equalTo(weakSelf.view).offset(bottom);

        }else{
            make.bottom.equalTo(weakSelf.view);
        }
        
        
    }];
    

/** 忽略多少scrollView的contentInset的bottom */
//@property (assign, nonatomic) CGFloat ignoredScrollViewContentInsetBottom;

            UIWindow *mainWindow = [[[UIApplication sharedApplication] delegate] window];
            CGFloat bottom = mainWindow.safeAreaInsets.bottom;//34
_tableView.mj_footer.ignoredScrollViewContentInsetBottom = isIphoneX ? bottom : 0;

static inline BOOL isIPhoneXSeries() {
    if (@available(iOS 11.0, *)) {
        UIWindow *mainWindow = [[[UIApplication sharedApplication] delegate] window];
        if (mainWindow.safeAreaInsets.bottom > 0.0) {
            return YES;
        }
    }
    return NO;
}