无法在 javafx 中设置静态 TextField 的值
Can't set the value of a static TextField in javafx
我正在开发一个用于保险目的的程序,我有一个名为 Reference Key 的 textfield,此参考密钥已生成每次我查看面板时,其他场景和 classes 都随机需要这个 Reference Key ,所以我把它设为静态,这样所有 classes 都可以直接访问这个实例!
我的问题是,当我为 文本字段 设置文本时,即使来自包含 textfield,但是当我删除 TextField 实例的静态关键字时,它完美地工作并且它的文本发生了变化!!
我的代码是这样的
@FXML
public static TextField ReferenceKey;
.
.
.
@Override
public void initialize(URL url, ResourceBundle rb) {
ReferenceKey.setText("ABCD");
}
我得到的异常
at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2601)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2579)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
at database.project.SceneManager.LoadPanel(SceneManager.java:55)
at database.project.HomePageController.lambda$initialize(HomePageController.java:83)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$ClickGenerator.postProcess(Scene.java:3470)
at javafx.scene.Scene$ClickGenerator.access00(Scene.java:3398)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3766)
at javafx.scene.Scene$MouseHandler.access00(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:381)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent4(GlassViewEventHandler.java:417)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null8(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
at database.project.CustmorInfoController.initialize(CustmorInfoController.java:100)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
... 37 more
我不知道为什么在倒数第 4 行显示
Caused by: java.lang.NullPointerException
我确定我只为 javafx 导入了文本字段
有人可以帮帮我吗
提前致谢。
JavaFX 不会将组件注入静态字段。如果可能,您应该传递此 class 的实例而不是使用静态字段。这可以通过允许方法和 class 使用此 class 将此 class 作为参数来实现。您还可以使用 FXMLLoader#getController
.
获取控制器
但是,如果需要,您可以拥有一个非静态字段并在 initialize
上设置一个静态字段:
@FXML
private TextField ReferenceKey;
public static TextField referenceKeyPublic;
...
@Override
public void initialize(URL url, ResourceBundle rb) {
ClassName.referenceKeyPublic = ReferenceKey;
}
我正在开发一个用于保险目的的程序,我有一个名为 Reference Key 的 textfield,此参考密钥已生成每次我查看面板时,其他场景和 classes 都随机需要这个 Reference Key ,所以我把它设为静态,这样所有 classes 都可以直接访问这个实例!
我的问题是,当我为 文本字段 设置文本时,即使来自包含 textfield,但是当我删除 TextField 实例的静态关键字时,它完美地工作并且它的文本发生了变化!!
我的代码是这样的
@FXML
public static TextField ReferenceKey;
.
.
.
@Override
public void initialize(URL url, ResourceBundle rb) {
ReferenceKey.setText("ABCD");
}
我得到的异常
at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2601)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2579)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
at database.project.SceneManager.LoadPanel(SceneManager.java:55)
at database.project.HomePageController.lambda$initialize(HomePageController.java:83)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$ClickGenerator.postProcess(Scene.java:3470)
at javafx.scene.Scene$ClickGenerator.access00(Scene.java:3398)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3766)
at javafx.scene.Scene$MouseHandler.access00(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:381)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent4(GlassViewEventHandler.java:417)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null8(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
at database.project.CustmorInfoController.initialize(CustmorInfoController.java:100)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
... 37 more
我不知道为什么在倒数第 4 行显示
Caused by: java.lang.NullPointerException
我确定我只为 javafx 导入了文本字段
有人可以帮帮我吗 提前致谢。
JavaFX 不会将组件注入静态字段。如果可能,您应该传递此 class 的实例而不是使用静态字段。这可以通过允许方法和 class 使用此 class 将此 class 作为参数来实现。您还可以使用 FXMLLoader#getController
.
但是,如果需要,您可以拥有一个非静态字段并在 initialize
上设置一个静态字段:
@FXML
private TextField ReferenceKey;
public static TextField referenceKeyPublic;
...
@Override
public void initialize(URL url, ResourceBundle rb) {
ClassName.referenceKeyPublic = ReferenceKey;
}