自学知识(五)

1.网络请求显示,请求成功显示,请求失败隐藏:

//显示状态栏的网络指示器

    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

 

2.是否显示引导页:

//是否显示引导页
-(void)showGuiView {
    
    //获得当前版本号
    NSString *currentVersion = [NSBundle mainBundle].infoDictionary[@"CFBundleShortVersionString"];
    //沙盒版本号
    NSString *lastVersion = [[NSUserDefaults standardUserDefaults] stringForKey:@"CFBundleShortVersionString"];
    
    if (![currentVersion isEqualToString:lastVersion]) {
        XFGuideView *guideView = [XFGuideView guideView];
        guideView.frame = self.window.bounds;
        [self.window addSubview:guideView];
        
        [[NSUserDefaults standardUserDefaults] setObject:currentVersion forKey:@"CFBundleShortVersionString"];
        //马上写入沙盒
        [[NSUserDefaults standardUserDefaults] synchronize];
        
    }
}

3.内存警告停止下载图片:

//当收到Received memory warning.会调用次方法
-(void)applicationDidReceiveMemoryWarning:(UIApplication *)application {
    SDWebImageManager *mgr = [SDWebImageManager sharedManager];
    //取消下载
    [mgr cancelAll];
    //清空缓存
    [mgr.imageCache clearMemory];

}

4.在子类化单元格类中:

// 从队列里面复用时调用

- (void)prepareForReuse {

    

    [super prepareForReuse];

    [_videoView reset];

    [_voiceView reset];

}

 

5.UIMenuController的使用:

-(IBAction)panGestureTop:(UILongPressGestureRecognizer *)longPress

02.{
03. 
04.UIMenuItem * itemPase = [[UIMenuItem alloc] initWithTitle:@"复制" action:@selector(copyimage)];
05.UIMenuItem * itemTrans = [[UIMenuItem alloc] initWithTitle:@"转发" action:@selector(trans)];
06.UIMenuItem * itemCollect = [[UIMenuItem alloc] initWithTitle:@"收藏" action:@selector(collect)];
07.UIMenuItem * itemJoin = [[UIMenuItem alloc] initWithTitle:@"加入" action:@selector(join)];
08. 
09.UIMenuController * menuController = [UIMenuController sharedMenuController];
10.[menuController setMenuItems: @[itemPase,itemCollect,itemTrans,itemJoin]];
11. 
12.CGPoint location = [longPress locationInView:[longPress view]];
13.CGRect menuLocation = CGRectMake(location.x, location.y, 0, 0);
14.[menuController setTargetRect:menuLocation inView:[longPress view]];
15.menuController.arrowDirection = UIMenuControllerArrowDown;
16. 
17.[menuController setMenuVisible:YES animated:YES];
18. 
19.}

6.对界面一样的可以复用控制器,简化代码,在控制器设置三目条件即可.

 每天进步一点点!!!