效果图 请看右下角的按钮
上代码，
创建控件
- (void)creatTapImageView {
self.tapView = [[UIView alloc] initWithFrame:CGRectMake(KScreenW - 80, KScreenH - 80, 50, 50)];
[self.view addSubview:_tapView];
[self.view bringSubviewToFront:_tapView];
_tapView.backgroundColor = [UIColor whiteColor];
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(gotoTopView:)];
_tapView.hidden = YES;
[_tapView addGestureRecognizer:tapGesture];
_tapView.layer.masksToBounds = YES;
_tapView.layer.cornerRadius = 25;
_tapView.layer.borderWidth = 2;
_tapView.layer.borderColor = YYColorFromRGB(0xd7d7d7).CGColor;
self.countLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 5, 50, 20)];
[self.tapView addSubview:_countLabel];
_countLabel.textAlignment = NSTextAlignmentCenter;
_countLabel.text = @"";
_countLabel.font = Font(14);
_countLabel.textColor = YYColorFromRGB(0x666666);
UIView *line = [[UIView alloc] initWithFrame:CGRectMake(7, 25, 36, 1)];
[_tapView addSubview:line];
line.backgroundColor = YYColorFromRGB(0xd7d7d7);
line.backgroundColor = [UIColor blackColor];
self.numLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 25, 50, 20)];
[self.tapView addSubview:_numLabel];
_numLabel.textAlignment = NSTextAlignmentCenter;
_numLabel.text = @"";
_numLabel.font = Font(14);
_numLabel.textColor = YYColorFromRGB(0x666666);
self.tapImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 50, 50)];
_tapImageView.image = [UIImage imageNamed:@"置顶"];
[_tapView addSubview:_tapImageView];
}
点击回到顶部
- (void)gotoTopView:(UITapGestureRecognizer *)gesture {
[self.chtableview setContentOffset:CGPointMake(0, 0) animated:YES];
}
我把他们写到这两个方法里是因为我的cell的高度不一样
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
NSLog(@"将要展示1******%ld^^^^^^%ld ",indexPath.section,_displayNum);
if (indexPath.section > 2) {
if (self.displayNum < indexPath.section) {
self.countLabel.text = [NSString stringWithFormat:@"%ld",indexPath.section + 1];
}
self.displayNum = indexPath.section;
if (indexPath.section < 2) { //如果上滑到顶部，则吧endDisplayNum置零 否者会出现 1
self.endDisplayNum = 0;
}
NSLog(@"将要展示2******%ld^^^^^^%ld ",indexPath.section,_displayNum);
}
}
- (void)tableView:(UITableView *)tableView didEndDisplayingCell:(nonnull UITableViewCell *)cell forRowAtIndexPath:(nonnull NSIndexPath *)indexPath {
NSLog(@"将要消失1******%ld^^^^%ld",indexPath.section,_endDisplayNum);
if (indexPath.section > 2) {
if (self.endDisplayNum > indexPath.section) {
self.countLabel.text = [NSString stringWithFormat:@"%ld",indexPath.section + 1];
}
self.endDisplayNum = indexPath.section;
NSLog(@"将要消失2******%ld^^^^%ld",indexPath.section,_endDisplayNum);
}
}
//开始拖动
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
self.tapImageView.hidden = YES;
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
self.tapImageView.hidden = NO;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (scrollView.contentOffset.y > 200) {
self.tapView.hidden = NO;
}else{
self.tapView.hidden = YES;
}
}