使用tableview做一个文字从下面往上滚动的效果

思路是：把tableview和cell都进行上下颠倒下，使用定时器，往数据源中增加数据，每个数据都是插入到第一个位置

#import "ViewController.h"
#import "customTableViewDataSource.h"
#import "CustomTableViewCell.h"

static const NSInteger maxCell = 7;

@interface ViewController ()
@property (nonatomic,strong)UITableView * myTableView;
@property (nonatomic,strong)customTableViewDataSource * dataSource;
@property (nonatomic,strong)NSMutableArray * textArr;
@end

@implementation ViewController

-(customTableViewDataSource *)dataSource{
    if (!_dataSource) {
        _dataSource = [[customTableViewDataSource alloc]init];
        _dataSource.isRow = NO;
    }
    return _dataSource;
}

- (NSMutableArray *)textArr
{
    if (!_textArr) {
        _textArr = [[NSMutableArray alloc] init];
    }
    return _textArr;
}
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    [self createTableView];
    [self setUpDataSource];

}
-(void)createTableView{
    UITableView * tableView = [[UITableView alloc]initWithFrame:CGRectMake(100, 100, 200, 200) style:UITableViewStylePlain];
    tableView.backgroundColor = [UIColor redColor];
    tableView.dataSource = self.dataSource;
    tableView.delegate = self.dataSource;
    self.dataSource.rowHeight= 30;
//    tableView.separatorStyle = UITableViewCellSeparatorStyleNone;

    [self.view addSubview:tableView];
    tableView.transform = CGAffineTransformMakeScale(1, -1);
    self.myTableView = tableView;
    
     [self tableViewConfig];
}

- (void)tableViewConfig{
    __weak typeof(self) weakSelf = self;
    self.dataSource.tableViewCell = ^UITableViewCell *(id  _Nonnull model) {
        CustomTableViewCell * cell = [CustomTableViewCell createChatTableViewCellWithTableView:weakSelf.myTableView];
//        cell.textLabel.text = model;
        [cell fillCellWithString:model];
        return cell;
    };
}

/**
 *  造点假数据
 */
- (void)setUpDataSource
{
    for (NSInteger i = 0; i < 6; i++) {
        NSMutableString *text = [[NSMutableString alloc] initWithString:@"哈"];
        for (NSInteger j = 0; j <= i; j++) {
            [text appendFormat:@"哈"];
        }
        [text appendFormat:@"%zd", i];
        [self.textArr addObject:text];
    }
    [NSTimer scheduledTimerWithTimeInterval:3 target:self selector:@selector(sendMessage) userInfo:nil repeats:YES];
}

- (void)sendMessage
{
    NSString *text = self.textArr[arc4random() % 6];
   
    [self.dataSource.dataSourceArray insertObject:text atIndex:0];
    [self.myTableView insertSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:UITableViewRowAnimationTop];
    if (self.dataSource.dataSourceArray.count > maxCell) {
        [self.dataSource.dataSourceArray removeLastObject];
        [self.myTableView deleteSections:[NSIndexSet indexSetWithIndex:self.dataSource.dataSourceArray.count] withRowAnimation:UITableViewRowAnimationNone];
    }
  
}

@end

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
NS_ASSUME_NONNULL_BEGIN
typedef UITableViewCell *(^tableViewCellBlock)(id model);
@interface customTableViewDataSource : NSObject<UITableViewDelegate,UITableViewDataSource>
@property (nonatomic,strong)NSMutableArray * dataSourceArray;
@property (nonatomic,copy)tableViewCellBlock tableViewCell;
/**
 *  设置是否是按组还是row  yes : row   no : section  默认是yes
 */
@property (nonatomic, assign) BOOL isRow;

/**
 *  设置tableviewcell的高度
 */
@property (nonatomic, assign) CGFloat rowHeight;

/**
 *  设置tableview头部view  默认无
 */
@property (nonatomic, strong) UIView *headView;

@end

NS_ASSUME_NONNULL_END

#import "customTableViewDataSource.h"

@interface customTableViewDataSource ()

@end
@implementation customTableViewDataSource
-(instancetype)init{
    self = [super init];
    if (self) {
        self.dataSourceArray = [NSMutableArray array];
        self.isRow = YES;
    }
    return self;
}


- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    if (self.isRow) {
        return 1;
    } else {
        return self.dataSourceArray.count;
    }
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    if (self.isRow) {
        return self.dataSourceArray.count;
    } else {
        return 1;
    }
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return self.rowHeight;
}

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    if (self.headView) {
        return self.headView;
    }
    return nil;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSString * model = self.dataSourceArray[indexPath.section];
    UITableViewCell *cell = nil;
    if (self.tableViewCell) {
       
        cell = self.tableViewCell(model);
    } else {
        cell = [[UITableViewCell alloc] init];
    }
    return cell;
}

- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
    if (self.headView) {
        return self.headView.bounds.size.height;
    }
    return 0;
}

- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section
{
    return 5.0;
}

- (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section
{
    return [[UIView alloc] init];
}

@end

#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface CustomTableViewCell : UITableViewCell
+ (instancetype)createChatTableViewCellWithTableView:(UITableView *)tableView;
-(void)fillCellWithString:(NSString *)sting;
@end

NS_ASSUME_NONNULL_END

#import "CustomTableViewCell.h"

@interface CustomTableViewCell ()
/**
 *  此处可以用lable直接使用
 */
@property (nonatomic, strong) UIView *mainView;

@end
@implementation CustomTableViewCell

- (void)awakeFromNib {
    [super awakeFromNib];
    // Initialization code
}
+ (instancetype)createChatTableViewCellWithTableView:(UITableView *)tableView{
    CustomTableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:@"CustomTableViewCell"];
    if (!cell) {
        cell = [[CustomTableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"PDChatTableViewCell"];
    }
    return cell;
}
-(instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier{
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self) {
        self.backgroundColor = [UIColor clearColor];
        self.contentView.backgroundColor = [UIColor clearColor];
        self.selectionStyle = UITableViewCellSelectionStyleNone;
        
        self.textLabel.font = [UIFont systemFontOfSize:14];
        self.textLabel.transform = CGAffineTransformMakeScale(1, -1);
        [self setUpCellUI];
    }
    return self;
}
-(void)setUpCellUI{
    
    UIView *cornerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 30, 30)];
    cornerView.backgroundColor = [UIColor whiteColor];
    cornerView.layer.cornerRadius = 3.0;
    cornerView.layer.masksToBounds = YES;
    [self.contentView insertSubview:cornerView belowSubview:self.textLabel];
    self.mainView = cornerView;
}
-(void)fillCellWithString:(NSString *)str{
    
    self.mainView.frame = CGRectMake(0, 0, 100, 30);
    self.textLabel.text = str;
}
- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
    [super setSelected:selected animated:animated];

    // Configure the view for the selected state
}

@end