title: Can't increase the width of an dialog box in flutter
body: <p>I need to build a pop up dialog box in my app. I am using Dialog class and wrapped it with SizedBox class to increase the width of the dialog box. But, the width of the dialog box is not increasing. How can I increase the width of it?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>onTap: () {
  showDialog(
      context: context,
      child:SizedBox(
          width: 900,
          child: Dialog(
              backgroundColor :Colors.white,
              insetAnimationDuration: const Duration(milliseconds: 10),
              shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
              child: Container(
                  child: Column(
                      children: &lt;Widget&gt;[
                          Text('hello'),
                          FlatButton(
                          onPressed: () {
                              Navigator.of(context).pop();
                          },
                          child: new Text("OK"),
                          ),
                      ]
                  ),
              ),  
          ),
      ),
  );
  },</code></pre>
  </div>
  </div>
  </p>