CA1057: String URI overloads call System.Uri overloads
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
| Item | Value |
|---|---|
| RuleId | CA1057 |
| Category | Microsoft.Design |
| Breaking change | Non-breaking |
Cause
A type declares method overloads that differ only by the replacement of a string parameter with a System.Uri parameter, and the overload that takes the string parameter does not call the overload that takes the Uri parameter.
Rule description
Because the overloads differ only by the string or Uri parameter, the string is assumed to represent a uniform resource identifier (URI). A string representation of a URI is prone to parsing and encoding errors, and can lead to security vulnerabilities. The Uri class provides these services in a safe and secure manner. To reap the benefits of the Uri class, the string overload should call the Uri overload using the string argument.
How to fix violations
Reimplement the method that uses the string representation of the URI so that it creates an instance of the Uri class using the string argument, and then passes the Uri object to the overload that has the Uri parameter.
When to suppress warnings
It is safe to suppress a warning from this rule if the string parameter does not represent a URI.
Example
The following example shows a correctly implemented string overload.
using System;
namespace DesignLibrary
{
public class History
{
public void AddToHistory(string uriString)
{
Uri newUri = new Uri(uriString);
AddToHistory(newUri);
}
public void AddToHistory(Uri uriType) { }
}
}
Imports System
Namespace DesignLibrary
Public Class History
Sub AddToHistory(uriString As String)
Dim newUri As New Uri(uriString)
AddToHistory(newUri)
End Sub
Sub AddToHistory(uriType As Uri)
End Sub
End Class
End Namespace
Related rules
CA2234: Pass System.Uri objects instead of strings
CA1056: URI properties should not be strings