iOS开发从入门到精通-- 警告对话框UIAlertView和等待提示器UIActivityIndicatorView

警告对话框uialertview和等待提示器uiactivityindicatorview:
1.uialertview简单一点就是弹框
2.就是所谓的菊花转圈圈

声明：注意@interface viewcontroller : uiviewcontroller这个里面多了一个uialertviewdelegate代理喎?https: www.2cto.com/kf/ware/vc/"="" target="_blank" class="keylink">vcd4ncjxwcmugy2xhc3m9"brush:java;"> #import @interface viewcontroller : uiviewcontroller{ //定义一个警告对话框视图对象 uialertview * _alertview; //等待提示对象 //当下载，或者加载比较大的文件时，可以显示此控件，处于提示等待状态 uiactivityindicatorview * _activityindicator; } @property(retain,nonatomic) uialertview * alertview; @property(retain,nonatomic) uiactivityindicatorview * activityindicator; @end

实现：

#import "viewcontroller.h"

@interface viewcontroller ()

@end

@implementation viewcontroller

//实现属性和成员变量的同步
@synthesize alertview =_alertview;
@synthesize activityindicator=_activityindicator;

- (void)viewdidload {
    [super viewdidload];
    // do any additional setup after loading the view, typically from a nib.
    for(int i=0;i<2;i++){
        uibutton * btn =[uibutton buttonwithtype:uibuttontyperoundedrect];
        btn.frame = cgrectmake(100, 100+100*i, 100, 40);
        if(i==0){
            [btn settitle:@"警告对话框" forstate:uicontrolstatenormal];
        }
        else if(i==1){
            [btn settitle:@"等待指示器" forstate:uicontrolstatenormal];
        }

        btn.tag = 101+i;

        [btn addtarget:self action:@selector(pressbtn:) forcontrolevents:uicontroleventtouchupinside];

        [self.view addsubview:btn];
    }
}

-(void) pressbtn:(uibutton*) btn{
    //警告对话框创建
    //p1:对话框标题
    //p2:提示信息
    //p3:处理按钮事件的代理对象
    //p4:取消按钮的文字,默认的索引为0；
    //p5:其他按钮文字 ** otherbuttontitles:@"确定", nil]; 只有取消和确定按钮是横向排开
    // otherbuttontitles:@"确定",@"确定1",@"确定2", nil];这样子就会全部纵向排开，索引依次是1，2，3.
    //p6:...:添加其他按钮
    //nil:表示按钮添加结束
    if(btn.tag==101){
        _alertview = [[uialertview alloc]initwithtitle:@"警告"
                                               message:@"你的手机电量过低，请保存数据"
                                              delegate:self
                                     cancelbuttontitle:@"取消"
                                     otherbuttontitles:@"确定", nil];

        //显示对话框
        [_alertview show];
    }
    //创建等待提示器，大伙都叫他菊花
    else if(btn.tag==102){
        //创建等待提示器，宽高不可变更
        _activityindicator =[[uiactivityindicatorview alloc]initwithframe:cgrectmake(100, 300, 80, 80)];

        //设定提示的风格:小灰，小白，大白
        _activityindicator.activityindicatorviewstyle =uiactivityindicatorviewstylegray;//小灰

//        _activityindicator.activityindicatorviewstyle=uiactivityindicatorviewstylewhite;//小白
//        
//        _activityindicator.activityindicatorviewstyle=uiactivityindicatorviewstylewhitelarge;//大白

//        self.view.backgroundcolor=[uicolor bluecolor];

        [self.view addsubview:_activityindicator];

        //启动动画并显示
        [_activityindicator startanimating];

        //停止等待动画并隐藏
//        [_activityindicator stopanimating];

    }
}

//当点击对话框的按钮时，调用此函数
//p1:对话框对象本身
//p2:按钮的索引
-(void) alertview:(uialertview *)alertview clickedbuttonatindex:(nsinteger)buttonindex{
    nslog(@"index=%ld\n",buttonindex);
}

//对话框即将消失，此函数被调用
-(void) alertview:(uialertview *)alertview willdismisswithbuttonindex:(nsinteger)buttonindex{
    nslog(@"即将消失！");
}

//对话框已经消失时，调用此函数
-(void) alertview:(uialertview *)alertview diddismisswithbuttonindex:(nsinteger)buttonindex{
    nslog(@"已经消失");
}

- (void)didreceivememorywarning {
    [super didreceivememorywarning];
    // dispose of any resources that can be recreated.
}

@end

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