UIAlertController的使用

在iOS 8中,苹果废弃了UIAlertView，UIActionSheet类,但仍然可用。你应该避免使用它,iOS的未来版本可能不支持它。
原文链接：UIAlertController Example in iOS
接下来我将交大家如何使用UIAlertController。
UIAlertController支持2中类型。使用UIAlertController你可以创建一个警告对话框(UIAlerview)或行动表(UIActionSheet).

 typedef NS_ENUM(NSInteger, UIAlertControllerStyle) {
 UIAlertControllerStyleActionSheet = 0,
 UIAlertControllerStyleAlert
 } NS_ENUM_AVAILABLE_IOS(8_0);
 

一下是在UIAlertController中非常有用的方法

 //Create UIAlertController
 
 
 
  
(instancetype)actionWithTitle:(NSString *)title style:(UIAlertActionStyle)style
 handler:(void (^)(UIAlertAction *action))handler;
 
 
 
 
//Adding an action
 
 
 
  
(void)addAction:(UIAlertAction *)action;
 
 
 
 
//Adding text filed to UIAlertController.This method is supported only for UIAlertControllerStyleAlert
 
 
 
  
(void)addTextFieldWithConfigurationHandler:(void (^)(UITextField *textField))configurationHandler;
 

• 创建一个简单的Alert Dialog

  
  
  
  
  

  
   UIAlertController * alert= [UIAlertController
   alertControllerWithTitle:@"My Title"
   message:@"Enter User Credentials"
   preferredStyle:UIAlertControllerStyleAlert];
   
  [self presentViewController:alert animated:YES completion:nil];
   

• 2创建一个alert Dialog with action

  
  
  
  
  

  
   UIAlertController * alert= [UIAlertController
   alertControllerWithTitle:@"Info"
   message:@"You are using UIAlertController"
   preferredStyle:UIAlertControllerStyleAlert];
   
  UIAlertAction* ok = [UIAlertAction
   actionWithTitle:@"OK"
   style:UIAlertActionStyleDefault
   handler:^(UIAlertAction * action)
   {
   [alert dismissViewControllerAnimated:YES completion:nil];
   
                    }];
   
  UIAlertAction* cancel = [UIAlertAction
   actionWithTitle:@"Cancel"
   style:UIAlertActionStyleDefault
   handler:^(UIAlertAction * action)
   {
   [alert dismissViewControllerAnimated:YES completion:nil];
   
                       }];
   
  [alert addAction:ok];
   [alert addAction:cancel];
   
  [self presentViewController:alert animated:YES completion:nil];
   

• 3 创建一个actionSheet with action

  
  
  
  
  

  
   UIAlertController * view= [UIAlertController
   alertControllerWithTitle:@"My Title"
   message:@"Select you Choice"
   preferredStyle:UIAlertControllerStyleActionSheet];
   
  UIAlertAction* ok = [UIAlertAction
   actionWithTitle:@"OK"
   style:UIAlertActionStyleDefault
   handler:^(UIAlertAction * action)
   {
   //Do some thing here
   [view dismissViewControllerAnimated:YES completion:nil];
   
                    }];
   
  UIAlertAction* cancel = [UIAlertAction
   actionWithTitle:@"Cancel"
   style:UIAlertActionStyleDefault
   handler:^(UIAlertAction * action)
   {
   [view dismissViewControllerAnimated:YES completion:nil];
   }];
   [view addAction:ok];
   [view addAction:cancel];
   [self presentViewController:view animated:YES completion:nil];
   

• 4. Create an Alert dialog with username and password fields.

     
     
     
     
     

     
      UIAlertController * alert= [UIAlertController
      alertControllerWithTitle:@"My Title"
      message:@"Enter User Credentials"
      preferredStyle:UIAlertControllerStyleAlert];
      

  UIAlertAction* ok = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault
  handler:^(UIAlertAction * action) {
  //Do Some action here

                                          }];
  

  UIAlertAction* cancel = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDefault
  handler:^(UIAlertAction * action) {
  [alert dismissViewControllerAnimated:YES completion:nil];
  }];

  [alert addAction:ok];
  [alert addAction:cancel];

  [alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
  textField.placeholder = @"Username";
  }];
  [alert addTextFieldWithConfigurationHandler:^(UITextField *textField) {
  textField.placeholder = @"Password";
  textField.secureTextEntry = YES;
  }];

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