IOS课程笔记[4-5] 计算器实现与更换主题 的使用

计算

控件介绍

文本输入

• 设置键盘格式为NumberPad
• 字符串与数字转换方法 NSInteger num2 =[str2 integerValue];

弹窗控件

• UIAlertController 新版本弹窗

 UIAlertController *alert =    [UIAlertController alertControllerWithTitle:@"error" message:@"输入有误" preferredStyle:UIAlertControllerStyleAlert];
        UIAlertAction *action =[UIAlertAction  actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

            NSLog(@"取消");       

        }];

        [alert addAction:action];

        [self presentViewController:alert animated:YES completion:nil];

• UIAlertView IOS9之前版本

   UIAlertView errView = [[UIAlertView alloc] initWithTitle:@"error" message:message delegate:nil cancelButtonTitle:@"ok" otherButtonTitles:nil, nil];

    [errView show]

实现逻辑

  NSLog(@" 点击按钮");

    //达到数字

    NSString *str1=  self.Num1Text.text;

    NSString *str2 = self.Num2Text.text;

    //转为数字

    NSInteger num1 =[str1 integerValue];

    NSInteger num2 =[str2 integerValue];

//校验

    if (num1 ==0 || num2 ==0){

        UIAlertController *alert =    [UIAlertController alertControllerWithTitle:@"error" message:@"输入有误" preferredStyle:UIAlertControllerStyleAlert];

        

        UIAlertAction *action =[UIAlertAction  actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

            NSLog(@"取消");

            

        }];

        [alert addAction:action];

        [self presentViewController:alert animated:YES completion:nil];

        return ;

    }

    //相加

    NSInteger result =num1+num2;

    //展示结果

    self.ResultLabel.text =[NSString stringWithFormat:@"%zd",result];

切换 主题

使用控件

• UISwitch 开关组件
• UISegmentedControl多选框

基本用法

-addTarget绑定点击或者切换事件

[sc addTarget:self action:@selector(changeThemeBystring:) forControlEvents:UIControlEventValueChanged];

代码实现

-(void) loadTopView{

     

    //添加文本

    UILabel *lb=[[UILabel alloc] init];

    [lb setText:@"更换主题"];

    [lb setFrame:CGRectMake(5, 0, 400, 40)];

     [self.topView addSubview:lb];

    //开关

    UISwitch *sw =[[UISwitch alloc] init];

    [sw setFrame:CGRectMake(200, 0, 200, 40)];

    [sw addTarget:self action:@selector(changeTheme:) forControlEvents:UIControlEventTouchUpInside];

    

    [self.topView addSubview:sw];

    

    

    //多选框

    UISegmentedControl *sc =[[UISegmentedControl alloc] initWithItems:@[@"yellow",@"red",@"green"]] ;

    [sc setFrame:CGRectMake(5, 55, 300, 40)];

    [sc addTarget:self action:@selector(changeThemeBystring:) forControlEvents:UIControlEventValueChanged];

    [self.topView addSubview: sc];

    

    //控件位置

    [self.topView  setCenter:CGPointMake(self.view.frame.size.width/2, self.view.frame.size.height/2) ];

}

#pragma mark 更换主题

- (void)changeTheme:(UISwitch *)sw{

    if(sw.isOn){

        self.view.backgroundColor= [UIColor whiteColor];

    }else{

        self.view.backgroundColor =[UIColor darkGrayColor];

    }

}

- (void)changeThemeBystring:(UISegmentedControl  *)sg{

    NSLog(@"%@",sg);

    switch  (sg.selectedSegmentIndex){

        case 0:            

            [self changeThemeBycolor:[UIColor yellowColor]];

            break;

        case 1:

            [self changeThemeBycolor:[UIColor redColor]];

            break;

        case 2:

            [self changeThemeBycolor:[UIColor greenColor]];

            break;          

    }

}

##效果展示