title: The argument type 'String' can't be assigned to the parameter type 'Uri' in Flutter
body: <p>Im using Flutter and I´m trying to conect my aplicaction to a database, however I can conect because always appear that error in this sentence (in url):</p>
  <pre><code>var response = await http.post(url, body: json.encode(data));
  </code></pre>
  <p>, Does anyone know what the problem is? Here is the code:</p>
  <pre><code>class LoginUserState extends State {
  
    // For CircularProgressIndicator.
    bool visible = false ;
  
    // Getting value from TextField widget.
    final emailController = TextEditingController();
    final passwordController = TextEditingController();
  
  Future userLogin() async{
  
    // Showing CircularProgressIndicator.
    setState(() {
    visible = true ; 
    });
  
    // Getting value from Controller
    String email = emailController.text;
    String password = passwordController.text;
  
    // SERVER LOGIN API URL
    var url = 'https://fluer-examples.com/login_user.php';
  
    // Store all data with Param Name.
    var data = {'email': email, 'password' : password};
  
    // Starting Web API Call.
    var response = await http.post(url, body: json.encode(data));
  
    // Getting Server response into variable.
    var message = jsonDecode(response.body);
  
    // If the Response Message is Matched.
    if(message == 'Login Matched')
    {
  
      // Hiding the CircularProgressIndicator.
        setState(() {
        visible = false; 
        });
  
      // Navigate to Profile Screen &amp; Sending Email to Next Screen.
        Navigator.push(
          context,
          MaterialPageRoute(builder: (context) =&gt; ProfileScreen(email : emailController.text))
        );
    }else{
  
      // If Email or Password did not Matched.
      // Hiding the CircularProgressIndicator.
      setState(() {
        visible = false; 
        });
  
      // Showing Alert Dialog with Response JSON Message.
      showDialog(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: new Text(message),
          actions: &lt;Widget&gt;[
            FlatButton(
              child: new Text(&quot;OK&quot;),
              onPressed: () {
                Navigator.of(context).pop();
              },
            ),
          ],
        );
      },
      );}
  
  }
  </code></pre>