新增一個button 等寬與檢視的寬度

tryButton = [UIButtonbuttonWithType:UIButtonTypeCustom];

tryButton.frame =CGRectMake(0,self.view.frame.size.height-44,self.view.frame.size.width,44);

// [tryButton setBackgroundImage:[UIImage imageNamed:@""] forState:UIControlStateNormal];

    [tryButtonsetBackgroundColor:[UIColorredColor]];

    [tryButtonaddTarget:selfaction:@selector(tryButtonAction)forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:tryButton];

新增在scrollView方法裡設定座標即可

-(void)scrollViewDidScroll:(UIScrollView *)scrollView

{

tryButton.frame =CGRectMake(0, (self.tableView.frame.size.height - 150

}