为tableview和collectionView添加数据为空的

简单有效的为UITableView和collectionView添加数据为空的提示

给UITableView添加一个如下分类，在数据源方法里面调用。

UITableView+EmptyData.h文件

#import <UIKit/UIKit.h>

@interface UITableView (EmptyData)
//添加图片和文字
- (void)tableViewDisplayWitMsg:(NSString *)message andImage:(NSString *) image forRowCount:(NSUInteger) rowCount;
//添加文字
- (void)tableViewDisplayWitMsg:(NSString *) message ifNecessaryForRowCount:(NSUInteger) rowCount;

@end

UITableView+EmptyData.m文件

#import "UITableView+EmptyData.h"

@implementation UITableView (EmptyData)

- (void)tableViewDisplayWitMsg:(NSString *)message andImage:(NSString *)image forRowCount:(NSUInteger)rowCount
{
    if (rowCount == 0) {
        
        UIView *backView = [[UIView alloc]initWithFrame:self.backgroundView.frame];
        UIImageView *imageView = [[UIImageView alloc] init];
        imageView.image = [UIImage imageNamed:image];
        [imageView sizeToFit];
        [backView addSubview:imageView];
        [imageView mas_makeConstraints:^(MASConstraintMaker *make) {
            make.centerX.equalTo(backView);
            make.centerY.equalTo(backView).offset(-80);
        }];
        UILabel *messageLabel = [UILabel new];
        messageLabel.text = message;
        messageLabel.numberOfLines = 0;
        messageLabel.font = [UIFont systemFontOfSize:14];
        messageLabel.textColor = [UIColor lightGrayColor];
        messageLabel.textAlignment = NSTextAlignmentCenter;
        [messageLabel sizeToFit];
        [backView addSubview:messageLabel];
        [messageLabel mas_makeConstraints:^(MASConstraintMaker *make) {
            make.top.equalTo(imageView.mas_bottom).offset(10);
            make.centerX.equalTo(backView);
        }];
        
        self.backgroundView = backView;
    } else {
        self.backgroundView = nil;
    }
}


- (void)tableViewDisplayWitMsg:(NSString *) message ifNecessaryForRowCount:(NSUInteger) rowCount
{
    if (rowCount == 0) {
        // Display a message when the table is empty
        // 没有数据的时候，UILabel的显示样式
        UILabel *messageLabel = [UILabel new];
        messageLabel.text = message;
        messageLabel.font = [UIFont systemFontOfSize:24];
//        messageLabel.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
        messageLabel.textColor = [UIColor lightGrayColor];
        messageLabel.textAlignment = NSTextAlignmentCenter;
        [messageLabel sizeToFit];

        self.backgroundView = messageLabel;
//        self.separatorStyle = UITableViewCellSeparatorStyleNone;
    } else {
        self.backgroundView = nil;
//        self.separatorStyle = UITableViewCellSeparatorStyleSingleLine;
    }
}
@end

给UICollectionView添加一个如下分类，在数据源方法里面调用。
UICollectionView+EmptyData.h文件

#import <UIKit/UIKit.h>
@interface UICollectionView (EmptyData)
//添加图片和文字
- (void)collectionViewDisplayWitMsg:(NSString *)message andImage:(NSString *) image forRowCount:(NSUInteger) rowCount;
//添加文字
- (void)collectionViewDisplayWitMsg:(NSString *) message ifNecessaryForRowCount:(NSUInteger) rowCount;
@end

UICollectionView+EmptyData.m文件

#import "UICollectionView+EmptyData.h"

@implementation UICollectionView (EmptyData)

- (void)collectionViewDisplayWitMsg:(NSString *)message andImage:(NSString *)image forRowCount:(NSUInteger)rowCount
{
    if (rowCount == 0) {
        
        UIView *backView = [[UIView alloc]initWithFrame:self.backgroundView.frame];
        UIImageView *imageView = [[UIImageView alloc] init];
        imageView.image = [UIImage imageNamed:image];
        [imageView sizeToFit];
        [backView addSubview:imageView];
        [imageView mas_makeConstraints:^(MASConstraintMaker *make) {
            make.centerX.equalTo(backView);
            make.centerY.equalTo(backView).offset(-80);
        }];
        UILabel *messageLabel = [UILabel new];
        messageLabel.text = message;
        messageLabel.numberOfLines = 0;
        messageLabel.font = [UIFont systemFontOfSize:14];
        messageLabel.textColor = [UIColor lightGrayColor];
        messageLabel.textAlignment = NSTextAlignmentCenter;
        [messageLabel sizeToFit];
        [backView addSubview:messageLabel];
        [messageLabel mas_makeConstraints:^(MASConstraintMaker *make) {
            make.top.equalTo(imageView.mas_bottom).offset(10);
            make.centerX.equalTo(backView);
        }];
        
        self.backgroundView = backView;
    } else {
        self.backgroundView = nil;
    }
}

- (void)collectionViewDisplayWitMsg:(NSString *)message ifNecessaryForRowCount:(NSUInteger)rowCount
{
    if (rowCount == 0) {
        //Display a message when the table is empty
        //没有数据的时候，UILabel的显示样式
        UILabel *messageLabel = [UILabel new];
        messageLabel.text = message;
        messageLabel.font = [UIFont systemFontOfSize:24];
        //messageLabel.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
        messageLabel.textColor = [UIColor lightGrayColor];
        messageLabel.textAlignment = NSTextAlignmentCenter;
        [messageLabel sizeToFit];
        
        self.backgroundView = messageLabel;
        //self.separatorStyle = UITableViewCellSeparatorStyleNone;
    } else {
        self.backgroundView = nil;
        //self.separatorStyle = UITableViewCellSeparatorStyleSingleLine;
    }
}