Question

我的情况是：我的TreeTableView有一个TreeTableColumn。列头文本将在运行时更改。

当我在显示舞台之前通过setText或textProperty().bind(...) 更改文字时，全部作为预期。
但是如果我在显示舞台后更改文字，我会得到一个巨大的 java.lang.ClassCastException 。我已经尝试使用Java SE 1.8.0 b132和Java 1.8.0_20 b17 EA。

除了重新创建TreeTableColumn？
之外，是否有解决方法？
我的示例代码：

TreeTableView<String> ttv = new TreeTableView<>(); TreeTableColumn<String, String> ttc = new TreeTableColumn<>(); ttc.setText("Hello"); ttv.getColumns().add(ttc); ttv.setOnMouseClicked(new EventHandler<MouseEvent>() { @Override public void handle(MouseEvent t) { ttc.setText("World"); } }); Scene scene = new Scene(ttv); primaryStage.setTitle("Hello World!"); primaryStage.setScene(scene); primaryStage.show();

例外（点击TreeTableView后）：

Exception in Application start method 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:483) at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:367) at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:305) 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:483) at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767) Caused by: java.lang.RuntimeException: Exception in Application start method at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:894) at com.sun.javafx.application.LauncherImpl.access$000(LauncherImpl.java:56) at com.sun.javafx.application.LauncherImpl$1.run(LauncherImpl.java:158) at java.lang.Thread.run(Thread.java:744) Caused by: java.lang.ClassCastException: javafx.scene.control.TreeTableColumn cannot be cast to javafx.scene.control.TableColumn at com.sun.javafx.scene.control.skin.TableHeaderRow$10.invalidated(TableHeaderRow.java:277) at javafx.beans.WeakInvalidationListener.invalidated(WeakInvalidationListener.java:83) at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:339) at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:80) at javafx.beans.property.StringPropertyBase.fireValueChangedEvent(StringPropertyBase.java:103) at javafx.beans.property.StringPropertyBase.markInvalid(StringPropertyBase.java:110) at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:143) at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:49) at javafx.scene.control.TableColumnBase.setText(TableColumnBase.java:189) at com.kalasch.test.TreeTableTest.start(TreeTableTest.java:39) at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837) at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335) at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301) at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298) at java.security.AccessController.doPrivileged(Native Method) at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298) at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95) at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39) at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112) ... 1 more Exception running application com.kalasch.test.TreeTableTest

更新08/04/2014：
向javafx-jira提交了错误报告：
https://bugs.openjdk.java.net/browse/JDK-8095931

更新08/05/2014：
修复版将为： 8u40
@ thatjavaguy09修复确实有效。

问候，卡尔什

Answer 1

查看堆栈跟踪，似乎问题是您的TreeTableColumn正在尝试转换为TableColumn，这就是抛出ClassCastException（因为它实际上是无效的转换）。

看来呼叫来自TableHeaderRow.invalidated。看看这个方法，我会看到演员来自哪里。

private final InvalidationListener columnTextListener = new InvalidationListener() {
    @Override public void invalidated(Observable observable) {
        **TableColumn<?,?> column = (TableColumn<?,?>) ((StringProperty)observable).getBean();**
        CheckMenuItem menuItem = columnMenuItems.get(column);
        if (menuItem != null) {
            menuItem.setText(getText(column.getText(), column));
        }
    }
};

这可能是JDK的一个错误。我相信正确的演员应该是一个TableColumnBase。我会将此提交给他们的bug跟踪器：

https://javafx-jira.kenai.com/secure/Dashboard.jspa

JavaFX 8 TreeTableColumn setText ClassCastException

1 个答案: