How to add multiple custom property in Visual WebPart?

Question

I'm trying to create multiple custom property in Visual WebPart in SharePoint Server but when building the SharePoint solution I get this error "Duplicate 'WebBrowsable' attribute"

This is my code to create multiple Custom Properties in Visual WebPart

 [WebBrowsable(true),
   WebDisplayName("User Name"),
   WebDescription("Enter User Name"),
   Personalizable(PersonalizationScope.Shared),
   Category("Mail Settings")]

 [WebBrowsable(true),
   WebDisplayName("Email"),
   WebDescription("Enter Email"),
   Personalizable(PersonalizationScope.Shared),
   Category("Mail Settings")]
 
 public string userName{
   get;
   set;
 }

 public string email{
   get;
   set;
 }

What am I doing wrong?

Answer 1

Adding multiple custom properties in Visual WebPart

First of all, you should be aware of the Custom WebPart Property block consists of two sections as below

[WebBrowsable(true),
  WebDisplayName("SMTP Server"),
  WebDescription("Enter SMTP Server"),
  Personalizable(PersonalizationScope.Shared),
  System.ComponentModel.Category("Mail Settings")
]

public string SMTPServer{
  get;
  set;
}

So to define multiple properties in Visual Webpart you have to repeat the full custom property block as per your count of custom property that you need to use as the following:

// First Property

[WebBrowsable(true),
  WebDisplayName("SMTP Server"),
  WebDescription("Enter SMTP Server"),
  Personalizable(PersonalizationScope.Shared),
  System.ComponentModel.Category("Mail Settings")
]

public string SMTPServer{
  get;
  set;
}


// Second Property

[WebBrowsable(true),
  WebDisplayName("SMTP Port"),
  WebDescription("Enter SMTP Port"),
  Personalizable(PersonalizationScope.Shared),
  System.ComponentModel.Category("Mail Settings")
]

public int SMTPPort{
  get;
  set;
}

For more details, Please check How to add Custom Property in Visual WebPart?