iOS基础控件---UIActivityIndicatorView

////  ViewController.h//  UIActivityIndicatorView////  Created by pengjiaxin on 2017/10/16.//  Copyright © 2017年 pengjiaxin. All rights reserved.//#import <UIKit/UIKit.h>@interface ViewController : UIViewController{        //等待提示对象    //当下载,或加载较大的文件时,可以显示此控件,处于等待状态    UIActivityIndicatorView *_activityIndicator;}@property (nonatomic, strong) UIActivityIndicatorView *activityIndicator;@end

////  ViewController.m//////  Created by pengjiaxin on 2017/10/16.//  Copyright © 2017年 pengjiaxin. All rights reserved.//#import "ViewController.h"@interface ViewController ()@end@implementation ViewController//同步---@synthesize activityIndicator = _activityIndicator;- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.            UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];    button.frame = CGRectMake(100, 100 + 100, 100, 40);    [button setTitleColor:[UIColor redColor] forState:UIControlStateNormal];        [button setTitle:@"等待对话框" forState:UIControlStateNormal];            [button addTarget:self action:@selector(buttonAction:) forControlEvents:UIControlEventTouchUpInside];    [self.view addSubview:button];        }-(void)buttonAction:(UIButton *)button{        //宽高不可变更    _activityIndicator = [[UIActivityIndicatorView alloc]initWithFrame:CGRectMake(150, 200, 80, 80)];    //小白,小灰,大白    _activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray;    [self.view addSubview:_activityIndicator];        //启动动画并显示    [_activityIndicator startAnimating];    //结束动画并隐藏    //        [_activityIndicator stopAnimating];    }- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end