title: dropdown button in flutter
body: <p>i want make drop down like this, i already add sizedbox(width : 20), but nothing happen <a href="https://i.stack.imgur.com/W8wGP.png" rel="nofollow noreferrer">This my Dropdown now</a>, Sry this is my first time using flutter, This is my code</p>
  <p>Container(</p>
  <pre><code>        margin: EdgeInsets.symmetric(horizontal: 20),
          height: 60,
          width: double.infinity,
          decoration: BoxDecoration(
            color: Colors.white,
            borderRadius: BorderRadius.circular(25),
            border: Border.all(color: Colors.black38),
          ),
          child: Stack(
            children: &lt;Widget&gt;[
                  Icon(
                  Icons.pin_drop,
                  color: Colors.orange,
                  size: 36,
              ),
              SizedBox(width: 20,),
              Expanded(
                child: DropdownButton(
                  isExpanded: true,
                  underline: SizedBox(),
                  icon: Icon(
                    Icons.arrow_drop_down,
                  ),
                  value: &quot;Jl. P. Diponegoro&quot;,
                  items: ['Jl. P. Diponegoro', 'Jl. Juanda', 'Jl. Perjuangan']
                      .map&lt;DropdownMenuItem&lt;String&gt;&gt;((String value) {
                    return DropdownMenuItem&lt;String&gt;(
                      value: value,
                      child: Text(value),
                    );
                  }).toList(),
                  onChanged: (value) {},
                ),
              ),
            ],
          ),
        ),
  </code></pre>