title: Flutter :- Custom showDialog with background Color
body: <p><a href="https://i.stack.imgur.com/9Jl5J.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9Jl5J.png" alt="enter image description here"></a></p>
  
  <pre><code>  void _showDialog(BuildContext context) {
      showDialog(
        context: context,
        builder: (BuildContext context) {  
          return AlertDialog(
            title: new Text("Alert Dialog title"),
            content: new Text("Alert Dialog body"),
            actions: &lt;Widget&gt;[
              // usually buttons at the bottom of the dialog
              new FlatButton(
                child: new Text("Close"),
                onPressed: () {
                  Navigator.of(context).pop();
                },
              ),
            ],
          );
        },
      );
    }
  </code></pre>
  
  <p>I need to create this event where at the moment of showing the dialogue window, the other part of the screen changes color, I am having trouble consulting other sources and the truth is that I cannot coincide with the event.</p>
  
  <p>The goal is to achieve something like this:</p>
  
  <p><a href="https://i.stack.imgur.com/h3upI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/h3upI.png" alt="enter image description here"></a></p>