JavaFX GridPane布局问题

Question

我有一个简单的登录表单。请参阅下面的原型：

我决定使用GridPane作为布局容器，无法通过居中和跨度提交按钮对齐LOGO。

那是我的login.fxml：

<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.image.ImageView?>
<?import javafx.scene.image.Image?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.control.Button?>

<GridPane alignment="CENTER" hgap="20" vgap="10">

  <ImageView fitHeight="82.0" fitWidth="296.0" pickOnBounds="true" preserveRatio="true" GridPane.rowIndex="0" GridPane.columnIndex="0" GridPane.columnSpan="2">
    <Image url="logo.png"/>
  </ImageView>

  <Label text="login:" GridPane.rowIndex="1" GridPane.columnIndex="0"/>
  <Label text="password:" GridPane.rowIndex="1" GridPane.columnIndex="1"/>

  <TextField prefWidth="200" prefHeight="20" GridPane.rowIndex="2" GridPane.columnIndex="0"/>
  <TextField prefWidth="200" prefHeight="20"  GridPane.rowIndex="2" GridPane.columnIndex="1"/>

  <Button text="submit" GridPane.rowIndex="3" GridPane.columnIndex="0" GridPane.columnSpan="2" GridPane.hgrow="ALWAYS" GridPane.fillWidth="true" />

</GridPane>

这就是我得到的：