javafx - 有没有办法改变源路径通过一个按钮
问题描述
我正在尝试通过按钮更改 VBox 的 fxml 代码,但该代码给了我一个 NullPointerException 错误:
这是我的 sample.fxml
<VBox fx:id="optionsVBox" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="515.0" prefWidth="515.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1">
<fx:include fx:id="VBoxInclude" source="VBox1.fxml"/>
</VBox>
有我的 VBox1(默认情况下):
<VBox fx:id="options" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="370.0" prefWidth="270.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
<children>
<HBox alignment="CENTER" VBox.vgrow="ALWAYS">
<children>
<Button mnemonicParsing="false" prefHeight="70.0" prefWidth="150.0" text="Options" onAction="#goToOptions">
<font>
<Font name="Century Gothic" size="20.0" />
</font>
</Button>
</children>
</HBox>
<HBox alignment="CENTER" VBox.vgrow="ALWAYS">
<children>
<Button mnemonicParsing="false" prefHeight="70.0" prefWidth="150.0" text="Re-Play?">
<font>
<Font name="Century Gothic" size="20.0" />
</font>
</Button>
</children>
</HBox>
</children>
</VBox>
并且当按下 VBox1 中的按钮时,示例的 fxml 路径应与此 VBOX2 交换
<VBox fx:id="change" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="370.0" prefWidth="270.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
<children>
<HBox alignment="CENTER" prefHeight="100.0" prefWidth="200.0">
<children>
<Button mnemonicParsing="false" prefHeight="70.0" prefWidth="150.0" text="Log out?">
<font>
<Font name="Century Gothic" size="20.0" />
</font>
</Button>
<Button mnemonicParsing="false" onAction="#goBack" prefHeight="70.0" prefWidth="100.0" text="Back..." HBox.hgrow="ALWAYS">
<HBox.margin>
<Insets left="5.0" />
</HBox.margin>
<font>
<Font name="Century Gothic" size="20.0" />
</font>
</Button>
</children>
</HBox>
</children>
</VBox>
还有我的控制器(当在 vbox 中按下按钮时,它应该用另一个 VBox 更改 VBox):
@FXML
public void goToOptions() throws IOException{
optionsVBox.getChildren().clear();
optionsVBox.getChildren().add(FXMLLoader.load(getClass().getResource("VBox2.fxml")));
}
@FXML
public void goBack() throws IOException {
optionsVBox.getChildren().clear();
optionsVBox.getChildren().add(FXMLLoader.load(getClass().getResource("VBox1.fxml")));
}
ps所有的fxml文件都在同一个包里
这是堆栈跟踪(希望我做得对)
Caused by: java.lang.NullPointerException
at sample.Controller.goToOptions(Controller.java:29)
... 58 more
这是它所指向的
optionsVBox.getChildren().clear();
optionsVBox.getChildren().add(FXMLLoader.load(getClass().getResource("/VBox2.fxml")));
其余的没有通往我的代码的路径
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8413)
at javafx.scene.control.Button.fire(Button.java:185)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:394)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$353(GlassViewEventHandler.java:432)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:431)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771)
... 48 more
解决方案
fx:controller
您的 VBox1 和 VBox2 fxml 文件定义中似乎都指定了问题。
让我提出以下解决方案:
示例.fxml
fx:include
选项和更改VBox
定义fx:id
为这两个VBox
es指定- 第二次将属性设置
visible
为managed
falseVBox
代码:
<?import javafx.scene.layout.VBox?>
<VBox fx:id="optionsVBox" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity"
prefHeight="515.0" prefWidth="515.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1"
fx:controller="sample.Controller">
<!-- controller set in top level VBox-->
<!-- both vboxes added as children, removed fx:controller from their definition -->
<fx:include source="optionsVBox.fxml" fx:id="options"/>
<!-- visible and managed is set to FALSE in the beginning -->
<!-- visible - whether user could see the control -->
<!-- managed - whether control occupies space in the layout -->
<fx:include source="changeVBox.fxml" fx:id="change" visible="false" managed="false"/>
</VBox>
选项Vbox.fxml
- 指定
fx:id
您希望在单击时发生某些事情的按钮 fx:controller
从顶层 VBox中删除- 从按钮中删除
onAction
- 稍后将在代码中连接
代码:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.text.Font?>
<VBox xmlns="http://javafx.com/javafx"
xmlns:fx="http://javafx.com/fxml"
prefHeight="400.0" prefWidth="600.0">
<HBox alignment="CENTER" VBox.vgrow="ALWAYS">
<!-- add fx:id to this button! -->
<Button mnemonicParsing="false" prefHeight="70.0" prefWidth="150.0" text="Options" fx:id="btnOptions">
<font>
<Font name="Century Gothic" size="20.0"/>
</font>
</Button>
</HBox>
<HBox alignment="CENTER" VBox.vgrow="ALWAYS">
<Button mnemonicParsing="false" prefHeight="70.0" prefWidth="150.0" text="Re-Play?">
<font>
<Font name="Century Gothic" size="20.0"/>
</font>
</Button>
</HBox>
</VBox>
改变Vbox.fxml
对 optionsVbox.fxml 执行相同的操作
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.VBox?>
<?import javafx.scene.text.Font?>
<VBox xmlns="http://javafx.com/javafx"
xmlns:fx="http://javafx.com/fxml"
maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity"
prefHeight="370.0" prefWidth="270.0">
<HBox alignment="CENTER" prefHeight="100.0" prefWidth="200.0">
<Button mnemonicParsing="false" prefHeight="70.0" prefWidth="150.0" text="Log out?">
<font>
<Font name="Century Gothic" size="20.0"/>
</font>
</Button>
<Button mnemonicParsing="false" prefHeight="70.0" prefWidth="100.0"
text="Back..." HBox.hgrow="ALWAYS" fx:id="btnChange">
<HBox.margin>
<Insets left="5.0"/>
</HBox.margin>
<font>
<Font name="Century Gothic" size="20.0"/>
</font>
</Button>
</HBox>
</VBox>
控制器.java
VBox
由他们fx:id
的 s连接- 使用函数
Button
通过他们的 s找到s并设置适当的回调fx:id
lookup
onAction
- 回调中的切换
visible
和managed
属性
代码:
package sample;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.layout.VBox;
public class Controller {
@FXML
public VBox change, options;
@FXML
void initialize() {
Button btnOptions = (Button) options.lookup("#btnOptions");
btnOptions.setOnAction(this::goToOptions);
Button btnChange = (Button) change.lookup("#btnChange");
btnChange.setOnAction(this::goBack);
}
@FXML
public void goBack(ActionEvent actionEvent) {
change.setVisible(false);
change.setManaged(false);
options.setVisible(true);
options.setManaged(true);
}
public void goToOptions(ActionEvent actionEvent) {
change.setVisible(true);
change.setManaged(true);
options.setVisible(false);
options.setManaged(false);
}
}
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