UIAlertController

//初始化方法

+ (instancetype)alertControllerWithTitle:(nullableNSString *)title message:(nullableNSString *)message preferredStyle:(UIAlertControllerStyle)preferredStyle;

//UIAlertControllerStyle
typedefNS_ENUM(NSInteger, UIAlertControllerStyle) {
UIAlertControllerStyleActionSheet =0, UIAlertControllerStyleAlert }
/**自动消失的UIAlertController*/ //创建UIAlertController
UIAlertController*alertController = [UIAlertControlleralertControllerWithTitle:@”标题”message:@”UIAlertController”preferredStyle:UIAlertControllerStyleAlert];

[selfpresentViewController:alertControlleranimated:YEScompletion:nil];

//线程2秒后执行
dispatch_after(dispatch_time(DISPATCH_TIME_NOW,
(int64_t)(2.f*NSEC_PER_SEC)),dispatch_get_main_queue(), ^{

    [alertControllerdismissViewControllerAnimated:YEScompletion:^{


    }];
});   /**************自动消失的UIAlertController*********/ 

/
**添加按钮**
Title :标题名称
style :样式[Cancle(取消)
Default(默认的) destructive(重置)]
handler:处理程序(点击按钮执行的代码) /

/**带按钮的的UIAlertController*/
//创建UIAlertController
UIAlertController*alertController = [UIAlertControlleralertControllerWithTitle:@”标题”message:@”UIAlertController”preferredStyle:UIAlertControllerStyleAlert];

//创建”取消”样式按钮
UIAlertActioncancelAction = [UIAlertActionactionWithTitle:@”取消”style:UIAlertActionStyleCancelhandler:^(UIAlertActionaction) {
//添加点击事件
self.view.backgroundColor= [UIColoryellowColor];

}];

//创建”默认”样式按钮
UIAlertActiondefaultAction = [UIAlertActionactionWithTitle:@”默认default”style:UIAlertActionStyleDefaulthandler:^(UIAlertAction_Nonnullaction) {

}];

//创建“警示”样式按钮
UIAlertActiondestructiveAction = [UIAlertActionactionWithTitle:@”重置deatructive” style:UIAlertActionStyleDestructivehandler:^(UIAlertAction_Nonnullaction) {

}];

//将按钮添加到alertController上
[alertControlleraddAction:cancelAction];
[alertControlleraddAction:defaultAction];
[alertControlleraddAction:destructiveAction];

[selfpresentViewController:alertControlleranimated:YEScompletion:nil];

/**带按钮的的UIAlertController*/

/**带输入框的UIAlertController*/ //创建UIAlertController
UIAlertController*alertController = [UIAlertControlleralertControllerWithTitle:@”文本对话框”message:@”登录和密码对话框示例”preferredStyle:UIAlertControllerStyleAlert];

//添加输入框
[alertControlleraddTextFieldWithConfigurationHandler:^(UITextField*textField){
textField.placeholder=@”登录”;

   //添加通知，监听输入框的变化
    [[NSNotificationCenterdefaultCenter]addObserver:selfselector:@selector(alertTextFieldDidChange:)name:UITextFieldTextDidChangeNotificationobject:textField];
}];

[alertControlleraddTextFieldWithConfigurationHandler:^(UITextField*textField) {
    textField.placeholder=@"密码";
    textField.secureTextEntry=YES;
}];

//添加按钮
UIAlertActionokAction = [UIAlertActionactionWithTitle:@”好的”style:UIAlertActionStyleDefaulthandler:^(UIAlertActionaction) {

   //获取到输入框的内容
   UITextField*login = alertController.textFields.firstObject;
   UITextField*password = alertController.textFields.lastObject;

   //移除通知
    [[NSNotificationCenterdefaultCenter]removeObserver:selfname:UITextFieldTextDidChangeNotificationobject:nil];

}];

//冻结按钮
okAction.enabled=NO;
[alertControlleraddAction:okAction];

[selfpresentViewController:alertControlleranimated:YEScompletion:^{


}];

/**带输入框的UIAlertController*/
}
//通知触发的方法

• (void)alertTextFieldDidChange:(NSNotification)notification{
  UIAlertControlleralertController = (UIAlertController*)self.presentedViewController;

  if(alertController) {

  UITextField*login = alertController.textFields.firstObject;
  UIAlertAction*okAction = alertController.actions.lastObject;
  
  //当输入的字数大于2时解冻
   okAction.enabled= login.text.length>2;
  

  }
  }