RAC-响应式编程之初体验

一.体验步骤:

1. 准备工作

1. 新建一个Xcode工程:RACDemo001
2. pod init
3. 在podfile文件里加上 pod ‘ReactiveObjC’ 
4. 终端输入: pod install,完成后重新打开程序,准备写代码

1. 开始体验(编写一个类似密码输入的UI:但并不是)

   1. 首先导入头文件: #import <ReactiveObjC.h>
   2. 代码正文:
   - (void)viewDidLoad {
       [super viewDidLoad];
       [self firstRAC];
   }
   - (void)firstRAC {
       UITextField *textField = [[UITextField alloc]initWithFrame:CGRectMake(self.view.center.x - 100, 100, 200, 40)];
       [self.view addSubview:textField];
       textField.borderStyle = UITextBorderStyleRoundedRect;
       textField.text = @"";
       textField.placeholder = @"请输入密码";
       textField.secureTextEntry = YES;
       
       NSMutableArray <UILabel *>*arrayM = [NSMutableArray array];
       for (NSInteger i = 0; i<=3; i++) {
           UILabel *label = [[UILabel alloc]init];
           label.tag = i;
           label.backgroundColor = [UIColor clearColor];
           [self.view addSubview:label];
           label.frame = CGRectMake(self.view.center.x + i*51 - 100, 150, 47, 10);
           [arrayM addObject:label];
       }
       
       UILabel *tipLabel = [[UILabel alloc]init];
       [self.view addSubview:tipLabel];
       tipLabel.frame = CGRectMake(self.view.center.x - 100, 170, 200, 10);
       tipLabel.font = [UIFont systemFontOfSize:11];
       tipLabel.textColor = [UIColor greenColor];
       tipLabel.text = @"";
       ///核心代码
       [[textField rac_signalForControlEvents:UIControlEventEditingChanged] subscribeNext:^(id x){
           NSLog(@"textField.text========%@", textField.text);
           
           NSInteger j = textField.text.length;
           NSInteger k = 0;
           if (j <= 0) {
               tipLabel.text = @"";
               k=0;
           }
           else if (j>0 && j<=6) {
               k = 1;
           }
           else if (j>6 && j<=9) {
               k=2;
           }
           else if (j>9 && j<=12) {
               k=3;
           }
           else if (j>12 && j<=15) {
               k=4;
           }
           else {
               return ;
           }
           
           for (NSInteger i = 0; i < 4; i++) {
               if (i <= k - 1) {
                   arrayM[i].backgroundColor = [UIColor magentaColor];
                   if (k == 1) {
                       tipLabel.text = @"密码太弱";
                       tipLabel.textColor = [UIColor grayColor];
                   }
                   else if (k==2) {
                       tipLabel.text = @"密码一般";
                       tipLabel.textColor = [UIColor orangeColor];
                   }
                   else if (k==3) {
                       tipLabel.text = @"密码较强";
                       tipLabel.textColor = [UIColor redColor];
                   }
                   else if (k==4) {
                       tipLabel.text = @"密码非常强";
                       tipLabel.textColor = [UIColor purpleColor];
                   }
               }
               else {
                   arrayM[i].backgroundColor = [UIColor clearColor];
               }
           }
       }];
   }

——–

效果图: