发表新帖
发表新帖

WPF-Prism CanExecute method not being called

前端 未结
关注
4 1334
南方客
南方客 2021-02-01 19:06

I am coding a simple login UserControl with two TextBoxes (Username and Password) and a Login button. I want the Login button to be enabled only when the username and password f

4条回答
  • 傲寒
    傲寒 (楼主)
    2021-02-01 19:36

    Starting with Prism6 the DelegateCommand can "observe" your propertys. Means everytime your property is changing the CanExecute-Method is called. The good thing is you get rid of RaiseCanExecuteChanged in the Propertysetter. You can also chain-call that method if you want to observe more properties:

    public LoginViewModel()
{
    this.LoginCommand =
        new DelegateCommand(
            this.LoginExecute, this.CanLoginExecute).ObservesProperty(() => Username).ObservesProperty(() => Password);
}



    Furthermore if you just want your DelegateCommand be called depending on the state of a boolean property you can use .ObservesCanExecute(()=> BoolProp)
    


    public LoginViewModel()
{
    this.LoginCommand =
        new DelegateCommand(
            this.LoginExecute).ObservesCanExecute(()=> IsServerOnline).ObservesProperty(() => Username).ObservesProperty(() => Password);
}



    You dont need this.CanLoginExecute anymore.
    
    
    
             
    
                                                        
    
            
            
    
              
                
                0
              
                   
                
               讨论(0)
              
                                                  
              
              
    
                          
             
       
          
              
    
                                       
    

    

                
    
                         
          
                              			
        
        
        
    
          
    
            
            
    
              
              
    
            
    


                                 
              
    
            
    
                          
    

        
         
    
                
                
    
                  
                
    
                
    
                   看不清?
                
    
              
    
                                  
    
                    
   
                 
             
              
    提交回复
    
            
    
          
    
        
    
      
       
      
    
    
    
          
 
     
 
    
        
    热议问题