DZNEmptyDataSet，優秀的空白頁或者出錯頁封裝

簡介

項目主頁:https://github.com/dzenbot/DZNEmptyDataSet

提示：主要用於UITableView和UICollectionView，也可以用於UIScrollView，其實主要是前兩個會用到空白或者網路出錯頁

採用給UIScrollView添加代理方法來給頁面添加空白頁，源碼很有學習意義

導入工程

自動，

pod 'DZNEmptyDataSet'

手動

https://github.com/dzenbot/DZNEmptyDataSet 下載解壓，Source文件夾下的文件拖入工程

導入頭文件：

#import "UIScrollView+EmptyDataSet.h"

初始化

    @interface MainViewController : UITableViewController <DZNEmptyDataSetSource, DZNEmptyDataSetDelegate>

    － (void)viewDidLoad {
         [super viewDidLoad];

         self.tableView.emptyDataSetSource = self;
         self.tableView.emptyDataSetDelegate = self;

    //這行代碼必須加上，可以去除tableView的多餘的線，否則會影響美觀
         self.tableView.tableFooterView = [UIView new];
    }

滿足代理方法，可以分別配置，都是可選的

空白頁圖片

    - (UIImage *)imageForEmptyDataSet:(UIScrollView *)scrollView {
    return [UIImage imageNamed:@"empty_placeholder"];
    }

圖片的動畫效果

    - (CAAnimation *)imageAnimationForEmptyDataSet:(UIScrollView *)scrollView {
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath: @"transform"];

    animation.fromValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
    animation.toValue = [NSValue valueWithCATransform3D:CATransform3DMakeRotation(M_PI_2, 0.0, 0.0, 1.0)];

    animation.duration = 0.25;
    animation.cumulative = YES;
    animation.repeatCount = MAXFLOAT;

    return animation;
    }

標題文本，詳細描述，富文本樣式

    - (NSAttributedString *)titleForEmptyDataSet:(UIScrollView *)scrollView {
    NSString *text = @"Please Allow Photo Access";

    NSDictionary *attributes = @{NSFontAttributeName: [UIFont boldSystemFontOfSize:18.0f],
                                 NSForegroundColorAttributeName: [UIColor darkGrayColor]};

    return [[NSAttributedString alloc] initWithString:text attributes:attributes];
    }
    
    - (NSAttributedString *)descriptionForEmptyDataSet:(UIScrollView *)scrollView {
    NSString *text = @"This allows you to share photos from your library and save photos to your camera roll.";

    NSMutableParagraphStyle *paragraph = [NSMutableParagraphStyle new];
    paragraph.lineBreakMode = NSLineBreakByWordWrapping;
    paragraph.alignment = NSTextAlignmentCenter;

    NSDictionary *attributes = @{NSFontAttributeName: [UIFont systemFontOfSize:14.0f],
                                 NSForegroundColorAttributeName: [UIColor lightGrayColor],
                                 NSParagraphStyleAttributeName: paragraph};

    return [[NSAttributedString alloc] initWithString:text attributes:attributes];                      
    }

按鈕文本或者背景樣式

    - (NSAttributedString *)buttonTitleForEmptyDataSet:(UIScrollView *)scrollView forState:(UIControlState)state {
    NSDictionary *attributes = @{NSFontAttributeName: [UIFont boldSystemFontOfSize:17.0f]};

    return [[NSAttributedString alloc] initWithString:@"Continue" attributes:attributes];
    }
    
    - (UIImage *)buttonImageForEmptyDataSet:(UIScrollView *)scrollView forState:(UIControlState)state {
    return [UIImage imageNamed:@"button_image"];
    }

空白頁的背景色

    - (UIColor *)backgroundColorForEmptyDataSet:(UIScrollView *)scrollView {
    return [UIColor whiteColor];
    }

如果需求無法滿足，你可以自定義

    - (UIView *)customViewForEmptyDataSet:(UIScrollView *)scrollView {
    //加入你自定義的view
    UIActivityIndicatorView *activityView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    [activityView startAnimating];
    return activityView;
    }

其他需求

    //是否顯示空白頁，預設YES
    - (BOOL)emptyDataSetShouldDisplay:(UIScrollView *)scrollView {
    return YES;
    }
    
    //是否允許點擊，預設YES
    - (BOOL)emptyDataSetShouldAllowTouch:(UIScrollView *)scrollView {
    return YES;
    }
    
    //是否允許滾動，預設NO
    - (BOOL)emptyDataSetShouldAllowScroll:(UIScrollView *)scrollView {
    return YES;
    }
    
    //圖片是否要動畫效果，預設NO
    - (BOOL) emptyDataSetShouldAllowImageViewAnimate:(UIScrollView *)scrollView {
    return YES;
    }
    
    //空白頁點擊事件
    - (void)emptyDataSetDidTapView:(UIScrollView *)scrollView {
    
    }
    
    //空白頁按鈕點擊事件
    - (void)emptyDataSetDidTapButton:(UIScrollView *)scrollView {
   
    }

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