我试图用forloop获取每个TextField的文本。 我尝试的是： 创建包含其中每个文本字段的TextField数组。 然后在有人按下按钮后我将进入一个for循环，它应该得到每个文本字段的值，但这不起作用，它给了我一个错误（我在帖子的末尾发布）。 当我选择一个文本字段时，它确实有效。像inputName.getText（）;然后它确实返回TextField的值，但当我尝试使用像textFields [i] .getText（）;它给了我一个错误。 这是一个JavaFX FXML应用程序 这是FXMLDocumentController.java文件
package justTesting;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
public class FXMLDocumentController implements Initializable {
@FXML
private TextField
inputName, inputAddress, inputCity, inputPostalcode, inputCountry, inputNumber, inputMail,
inputLabel, inputFlight, inputDestination,
inputType, inputBrand, inputColor, inputSpecial;
@FXML
private TextField[] textFields = {
inputName, inputAddress, inputCity, inputPostalcode, inputCountry, inputNumber, inputMail,
inputLabel, inputFlight, inputDestination,
inputType, inputBrand, inputColor, inputSpecial};
@FXML
private String[] dataTypes = {"Name: ", "Address: ", "City: ", "Postalcode: ", "Country: ", "Phone Number: ", "E-Mail: ",
"Label Tag: ", "Flight number: ", "Destination: ",
"Type: ", "Brand: ", "Color: ", "Special characteristics: "};
@FXML
private Label label;
@FXML
private void getInputButton(ActionEvent event) {
System.out.println("Dit is alleen ter verduidelijking voor de designers");
for (int i = 0; i < textFields.length; i++) {
System.out.println(textFields[i].getText());
//the following line causes the error ( textFields[i].getText() )
System.out.printf("%-20s%10s\n", dataTypes[i], textFields[i].getText());
}
}
@Override
public void initialize(URL url, ResourceBundle rb) {
// TODO
}
}
有谁知道获取每个文本字段值的正确方法（使用forloop是什么？）
它给我的错误：
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.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.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$MouseEventNotification.run(GlassViewEventHandler.java:381)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:417)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
... 52 more
Caused by: java.lang.NullPointerException
at lostandfoundluggageform.FXMLDocumentController.getInputButton(FXMLDocumentController.java:47)
... 62 more
答案 0 :(得分：1)
初始化initialize()方法中的文本字段数组。在初始化数组时（在类初始值设定项中），FXMLLoader不能注入文本字段，并且仍然为空。因此，您的数组只是充满了空引用。
假设您未发布的代码中没有错误，则以下内容应该有效：
public class FXMLDocumentController implements Initializable {
@FXML
private TextField
inputName, inputAddress, inputCity, inputPostalcode, inputCountry, inputNumber, inputMail,
inputLabel, inputFlight, inputDestination,
inputType, inputBrand, inputColor, inputSpecial;
private TextField[] textFields ;
// ...
@Override
public void initialize(URL url, ResourceBundle rb) {
textFields = new TextField[] {
inputName, inputAddress, inputCity, inputPostalcode, inputCountry, inputNumber, inputMail,
inputLabel, inputFlight, inputDestination,
inputType, inputBrand, inputColor, inputSpecial} ;
}
}