如果用户将制表符粘贴到 TextField
中,JavaFX 应用程序线程将抛出 StringIndexOutOfBoundsException
。我怎样才能巧妙地防止用户以这种方式破坏我的应用程序?
这是一个演示该行为的最小示例。
//Defined in Main.java
public class Main extends Application {
@Override
public void start(Stage primaryStage) {
try {
AnchorPane root = (AnchorPane) FXMLLoader
.load(getClass().getResource("MainView.fxml"));
primaryStage.setScene(new Scene(root));
primaryStage.show();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}
在 MainView.fxml 中定义:
<AnchorPane xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
<children>
<TextField fx:id="tf" />
</children>
</AnchorPane>
程序:
- 复制制表符(
\t
)到剪贴板 - 在
TextField
中输入内容 - 突出显示
TextField
中的文本 - 粘贴剪贴板的内容以替换突出显示的文本
无论用户使用键盘快捷键(Windows 中的 Ctrl+V)还是上下文菜单,都会发生异常。我当然可以向每个 TextField
添加一个 try-catch block ,但这会使代码困惑,我怎么知道这个异常只在这种情况下抛出?
注意:这个问题似乎不会影响 TextArea
异常全文:
Exception in thread "JavaFX Application Thread" java.lang.StringIndexOutOfBoundsException: String index out of range: 1
at java.lang.AbstractStringBuilder.substring(Unknown Source)
at java.lang.StringBuilder.substring(Unknown Source)
at javafx.scene.control.TextField$TextFieldContent.get(Unknown Source)
at javafx.scene.control.TextInputControl.getText(Unknown Source)
at javafx.scene.control.TextInputControl.updateContent(Unknown Source)
at javafx.scene.control.TextInputControl.replaceText(Unknown Source)
at javafx.scene.control.TextInputControl.replaceText(Unknown Source)
at javafx.scene.control.TextInputControl.replaceSelection(Unknown Source)
at javafx.scene.control.TextInputControl.paste(Unknown Source)
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.paste(Unknown Source)
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.callAction(Unknown Source)
at com.sun.javafx.scene.control.behavior.BehaviorBase.callActionForEvent(Unknown Source)
at com.sun.javafx.scene.control.behavior.TextInputControlBehavior.callActionForEvent(Unknown Source)
at com.sun.javafx.scene.control.behavior.BehaviorBase.lambda$new$74(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at javafx.event.Event.fireEvent(Unknown Source)
at javafx.scene.Scene$KeyHandler.process(Unknown Source)
at javafx.scene.Scene$KeyHandler.access$1800(Unknown Source)
at javafx.scene.Scene.impl_processKeyEvent(Unknown Source)
at javafx.scene.Scene$ScenePeerListener.keyEvent(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleKeyEvent$353(Unknown Source)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(Unknown Source)
at com.sun.glass.ui.View.handleKeyEvent(Unknown Source)
at com.sun.glass.ui.View.notifyKey(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(Unknown Source)
at java.lang.Thread.run(Unknown Source)
最佳答案
那太丑了。您应该将此报告为错误。
您可以使用过滤掉制表符(和换行符)的 TextFormatter
解决此问题。您可能希望将制表符替换为例如四个空格。
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.control.TextFormatter;
import javafx.scene.control.TextFormatter.Change;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
public class TextFieldBug extends Application {
@Override
public void start(Stage primaryStage) {
TextField tf = new TextField();
tf.setTextFormatter(new TextFormatter<String>((Change c) -> {
String text = c.getText();
int oldAnchor = c.getAnchor();
int oldCaretPos = c.getCaretPosition() ;
int initialLength = text.length();
text = text.replaceAll("\t", " ");
text = text.replaceAll("\n", "");
c.setText(text);
c.setAnchor(oldAnchor + text.length() - initialLength);
c.setCaretPosition(oldCaretPos + text.length() - initialLength);
return c ;
}));
primaryStage.setScene(new Scene(new StackPane(tf), 350, 120));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
关于java - 将 Tab 字符粘贴到 TextField 时破坏 JavaFX,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36009368/