[某鸥实训记][objective-c][第五天][个人笔记]

TableView+ScrollView

• 往cell里加label
• 解决重影的办法
• 重用cell的时候删除元素

NSArray *subViews = cell.subviews;

    for (UIView *view in subViews) {

        [view removeFromSuperview];

    }

• 在if(cell==nil)中去定义子视图,加上tag值.在外边通过tag值获取视图,修改值
• 封装一个自定义的cell类

//http://www.tuicool.com/articles/bE7JNnI

• 将获得cell的方法从- (UITableViewCell*)dequeueReusableCellWithIdentifier:(NSString*)identifier 换为-(UITableViewCell *)cellForRowAtIndexPath:(NSIndexPath *)indexPath.重用机制调用的就是dequeueReusableCellWithIdentifier这个方法，方法的意思就是“出列可重用的cell”，因而只要将它换为cellForRowAtIndexPath（只从要更新的cell的那一行取出cell），就可以不使用重用机制，因而问题就可以得到解决，虽然可能会浪费一些空间。
• 通过为每个cell指定不同的重用标识符(reuseIdentifier)来解决。重用机制是根据相同的标识符来重用cell的，标识符不同的cell不能彼此重用。于是我们将每个cell的标识符都设置为不同，就可以避免不同cell重用的问题了。

//http://www.mamicode.com/info-detail-470734.html

下面是用ScrollView的一段代码

- (void)viewDidLoad {
    [super viewDidLoad];
    //控制条?不透明
    self.navigationController.navigationBar.translucent = NO;
    UIScrollView *scroll = [[UIScrollView alloc] init];
    scroll.frame = self.view.frame;
    scroll.backgroundColor = [UIColor darkGrayColor];
    scroll.contentSize = CGSizeMake(self.view.frame.size.width*5, self.view.frame.size.height-64);
    NSLog(@"%f",(double) self.navigationController.navigationBar.frame.size.height);
    //一页一页的滑动
    scroll.pagingEnabled = YES;
    scroll.contentOffset = CGPointMake(self.view.frame.size.width*2,0);
    [self.view addSubview:scroll];
    
    for (int i=0;i<5; i++) {
        UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(image)];
        UIImageView *imageView = [[UIImageView alloc] init];
        imageView.userInteractionEnabled = YES;
        imageView.frame = CGRectMake(self.view.frame.size.width*i, 0, self.view.frame.size.width, self.view.frame.size.height-64);
        NSLog(@"%f",(double) self.navigationController.navigationBar.frame.size.height);
        imageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"t%d.png",i+1]];
        [imageView addGestureRecognizer:tap];
        [scroll addSubview:imageView];
    }
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)image{
    FirstViewController *firstVC = [FirstViewController new];
    [self.navigationController pushViewController:firstVC animated:YES];
}