示例。f xml
<AnchorPane prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/9.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="SampleController">
<children>
<ScrollPane AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<content>
<GridPane fx:id="gridPane" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<columnConstraints>
<ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
</columnConstraints>
</GridPane>
</content>
</ScrollPane>
</children>
</AnchorPane>
sampleController.java
public class SampleController {
@FXML public GridPane gridPane;
@FXML
public void initialize(){
RowConstraints rowConstraints = new RowConstraints(10.0, 40, 40);
ColumnConstraints columnConstraints = new ColumnConstraints(10.0, 40, 40);
int i=0,j=0;
for(i=0; i<50; i++){
gridPane.getRowConstraints().add(i, rowConstraints);
for(j=0; j<30; j++) {
gridPane.getColumnConstraints().add(j, columnConstraints);
Button btn = new Button(Integer.toString(j+1));
btn.setPrefSize(40, 40);
gridPane.add(btn, j, i);
}
}
}
}
Dashboard.java
public class sample extends Application{
public static void main(String[] args){
launch(args);
}
@Override
public void start(Stage stage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
Scene scene = new Scene(root, 300, 275);
stage.setTitle("FXML Welcome");
stage.setScene(scene);
stage.show();
}
}
您正在为每一行添加列列约束，这意味着最终您将拥有50*30=1500约束而不是30。您需要在行循环之外的循环中添加列约束。此外，假设在添加约束之前约束列表是空的，您不需要指定要插入的索引，因为add也会插入到List的末尾。请检查，如果您真的需要在fxml中创建的列约束，因为代码变得更简单了，如果您不需要将列约束作为列表的倒数第二个元素插入：
for (int i = 0; i < 30; i++) {
gridPane.getColumnConstraints().add(columnConstraints);
}
for(int i = 0; i < 50; i++){
gridPane.getRowConstraints().add(rowConstraints);
for(int j = 0; j < 30; j++) {
Button btn = new Button(Integer.toString(j + 1));
btn.setPrefSize(40, 40);
gridPane.add(btn, j, i);
}
}
BTW：注意AnchorPane约束对不是AnchorPane子项的节点没有任何影响；您可以安全地从fxml中的GridPane中删除这些约束。
