title: space between items in gridview flutter
body: <p>I have a gridview with 6 items (cards with images and text). I want those 6 items to fit me on the screen but the gridview leaves all the space I can between items by jumping 2 items off the screen.</p>
  
  <p>I leave a picture of what I want and what I have.</p>
  
  <p>Thank you.</p>
  
  <pre><code>return MaterialApp(
      home: Scaffold(
          body: Container(
    margin: EdgeInsets.only(top: 0),
    child: Stack(
      alignment: AlignmentDirectional.topCenter,
      children: &lt;Widget&gt;[
        Container(
          height: 200,
          color: Colors.black,
        ),
        Container(
          margin: EdgeInsets.only(top: 200),
          decoration: BoxDecoration(
              image: new DecorationImage(
                  image: AssetImage("assets/fondo.png"), fit: BoxFit.fill)),
        ),
        Image.asset("assets/cara_simio_banner.png"),
        Padding(
          padding: EdgeInsets.only(top: 220),
          child: Text(
            "{CodeJaVu}",
            style: TextStyle(
                color: Colors.white,
                fontSize: 25,
                fontWeight: FontWeight.bold),
          ),
        ),
        Container(
          margin: EdgeInsets.only(top: 230),
          child: GridView.count(
            crossAxisCount: 2,
            children: items.map((item) {
              return GestureDetector(
                onTap: () {},
                child: CardItem(item),
              );
            }).toList(),
          ),
        )
      ],
    ),
  )));
  </code></pre>
  
  <p>}</p>
  
  <pre><code>Widget CardItem(Item item) {
  return Card(
    margin: EdgeInsets.all(40),
    shape: RoundedRectangleBorder(
      borderRadius: BorderRadius.circular(15.0),
    ),
  
      child: 
        Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: &lt;Widget&gt;[
            Image.asset(
              item.image,
              width: 50,
              height: 50,
            ),
            Text(item.name)
          ],
        )
  );
  }
  
  class Item {
   String _name;
   String _image;
  
   Item(this._name, this._image);
   String get name =&gt; _name;
   set name(String name) =&gt; _name = name;
  
   String get image =&gt; _image;
   set image(String image) =&gt; _image = image;
  }
  </code></pre>
  
  <p>what I have,</p>
  
  <p><img src="https://i.stack.imgur.com/uC8zj.png" alt="what I have"></p>
  
  <p>what I want,</p>
  
  <p><img src="https://i.stack.imgur.com/VLLqb.png" alt="what I want"></p>