How to create a custom Dialog in flutter

Question

I want to create a custom dialog as shown below. I am able to create a normal dialog with two buttons(the positive and negative buttons). But I searched a lot about creating custom dialog like the one shown below but in vain.

showAlertDialog(BuildContext context) {

    // set up the buttons
    Widget cancelButton = FlatButton(
      child: Text("Cancel"),
      onPressed:  () {},
    );
    Widget continueButton = FlatButton(
      child: Text("Continue"),
      onPressed:  () {},
    );

    // set up the AlertDialog
    AlertDialog alert = AlertDialog(
      title: Text("Action"),
      content: Text("Would you like to continue learning how to use Flutter alerts?"),
      actions: [
        cancelButton,
        continueButton,
      ],
    );

    // show the dialog
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return alert;
      },
    );
  }

Now I want to have these buttons and the image as the children of the dialog and the icon button 'X' in the bottom to close the dialog. Any help is appreciated. I am a complete beginner in flutter.

Solution

For it, we create a custom dialog

1. Custom Dialog Content class

class CustomDialog extends StatelessWidget {

  dialogContent(BuildContext context) {
    return Container(
      decoration: new BoxDecoration(
        color: Colors.white,
        shape: BoxShape.rectangle,
        borderRadius: BorderRadius.circular(10),
        boxShadow: [
          BoxShadow(
            color: Colors.black26,
            blurRadius: 10.0,
            offset: const Offset(0.0, 10.0),
          ),
        ],
      ),
      child: Column(
        mainAxisSize: MainAxisSize.min, // To make the card compact
        children: <Widget>[
          Image.asset('assets/images/image.jpg', height: 100),
          Text(
            "Text 1",
            style: TextStyle(
              fontSize: 24.0,
              fontWeight: FontWeight.w700,
            ),
          ),
          SizedBox(height: 16.0),
          Text(
            "Text 1",
            style: TextStyle(
              fontSize: 24.0,
              fontWeight: FontWeight.w700,
            ),
          ),
          SizedBox(height: 24.0),
          Align(
            alignment: Alignment.bottomCenter,
            child: Icon(Icons.cancel),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Dialog(
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(10),
      ),
      elevation: 0.0,
      backgroundColor: Colors.transparent,
      child: dialogContent(context),
    );
  }
}

2. Call Custom Dialog on Click:

RaisedButton(
            color: Colors.redAccent,
            textColor: Colors.white,
            onPressed: () {
              showDialog(
                  context: context,
                  builder: (BuildContext context) {
                    return CustomDialog();
                  });
              ;
            },
            child: Text("PressMe"),
          ),