AFN在子线程加载数据，当需要先加载数据，后显示视图时，将显示视图写在success方法中

//存放所有的地区对象
@property(nonatomic,strong)NSMutableArray *allarray;

-(void)loadRegionData
{
    AFHTTPRequestOperationManager *manager=[AFHTTPRequestOperationManager manager];
    NSString*url=[NSString stringWithFormat:@"%@",CLPLACELIST];
    
    [manager POST:url parameters:nil success:^(AFHTTPRequestOperation * _Nonnull operation, id  _Nonnull responseObject) {
        
        if (responseObject!=nil) {
            
            NSDictionary *dictionary=responseObject[@"obj"];
            NSArray *array=dictionary[@"city"];
            
            self.allarray=[NSMutableArray array];
            
            for (NSDictionary *dict in array) {
                RegionModel *regionModel=[[RegionModel alloc] init];
                [regionModel setValuesForKeysWithDictionary:dict];
                [_allarray addObject:regionModel];
                
            }

            //九宫格布局
              [self layoutButtons];
            
            
        }
 
} failure:^(AFHTTPRequestOperation * _Nullable operation, NSError * _Nonnull error) {
    NSLog(@"******region*****%@",error);
    
}];
    

}

-(void)layoutButtons
{
    
    //完成布局设计
    
    //三列
    int totalloc=3;
    // 宽度
    CGFloat appvieww=85;
    //高度
    CGFloat appviewh=30;
    
    CGFloat margin=(WIDTHW-totalloc*appvieww)/(totalloc+1);
    CGFloat marginY=10;

    for (int i=0; i<self.allarray.count; i++) {
        int row=i/totalloc;//行号
        //1/3=0,2/3=0,3/3=1;
        int loc=i%totalloc;//列号
        
        CGFloat appviewx=margin+(margin+appvieww)*loc;
        CGFloat appviewy=marginY+(marginY+appviewh)*row;
        
        //创建地区按钮
        UIButton *regionBtn=[[UIButton alloc] initWithFrame:CGRectMake(appviewx, appviewy+64, appvieww, appviewh)];
        [self.view addSubview:regionBtn];
        //regionBtn.backgroundColor=[UIColor greenColor];
        NSLog(@"#####buttons###allarray###%@",self.allarray[i]);
        regionBtn.titleLabel.font=[UIFont systemFontOfSize:12];
        RegionModel *regionModel=[[RegionModel alloc] init];
        regionModel=_allarray[i];
        [regionBtn setTitle:regionModel.name forState:UIControlStateNormal];
        [regionBtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        [regionBtn addTarget:self action:@selector(didClickRegion) forControlEvents:UIControlEventTouchUpInside];
        
    }
    
}