为什么我的 GroupLayout 出现 'exception in main' 错误？

Question

我想使用 GroupLayout 来获得 usernameLabel/Field 和 passwordLabel/Field 显示，如下所示：

用户名：用户名字段
密码：密码字段

我使用的代码如下：

layout.setHorizontalGroup(
            layout.createSequentialGroup()
                .addGroup(layout.createParallelGroup(GroupLayout.Alignment.BASELINE)
                .addComponent(usernameLabel)
                .addComponent(usernameField) 
                    )
                .addGroup(layout.createParallelGroup(GroupLayout.Alignment.BASELINE)
                    .addComponent(passwordLabel)
                    .addComponent(passwordField)
                    )
            );

        layout.setVerticalGroup(
            layout.createParallelGroup(GroupLayout.Alignment.BASELINE)
                .addGroup(layout.createSequentialGroup()
                    .addComponent(usernameLabel)
                    .addComponent(usernameField)
                     )
                .addGroup(layout.createSequentialGroup()
                    .addComponent(passwordLabel)
                    .addComponent(passwordLabel)
                    )
            );

编译成功但出现以下错误：

Exception in thread "main" java.lang.IllegalStateException: javax.swing.JPasswordField[,0,0,0x0,invalid,layout=javax.swing.plaf.basic.BasicTextUI$UpdateHandler,alignmentX=0.0,alignmentY=0.0,border=com.apple.laf.AquaTextFieldBorder@5910e440,flags=288,maximumSize=,minimumSize=,preferredSize=,caretColor=javax.swing.plaf.ColorUIResource[r=0,g=0,b=0],disabledTextColor=javax.swing.plaf.ColorUIResource[r=128,g=128,b=128],editable=true,margin=javax.swing.plaf.InsetsUIResource[top=0,left=0,bottom=0,right=0],selectedTextColor=com.apple.laf.AquaImageFactory$SystemColorProxy[r=0,g=0,b=0],selectionColor=com.apple.laf.AquaImageFactory$SystemColorProxy[r=164,g=205,b=255],columns=20,columnWidth=0,command=,horizontalAlignment=LEADING,echoChar=●] is not attached to a vertical group
    at javax.swing.GroupLayout.checkComponents(GroupLayout.java:1090)
    at javax.swing.GroupLayout.prepare(GroupLayout.java:1040)
    at javax.swing.GroupLayout.layoutContainer(GroupLayout.java:910)
    at java.awt.Container.layout(Container.java:1510)
    at java.awt.Container.doLayout(Container.java:1499)
    at java.awt.Container.validateTree(Container.java:1695)
    at java.awt.Container.validateTree(Container.java:1704)
    at java.awt.Container.validateTree(Container.java:1704)
    at java.awt.Container.validateTree(Container.java:1704)
    at java.awt.Container.validateTree(Container.java:1704)
    at java.awt.Container.validate(Container.java:1630)
    at java.awt.Container.validateUnconditionally(Container.java:1667)
    at java.awt.Window.show(Window.java:1033)
    at java.awt.Component.show(Component.java:1671)
    at java.awt.Component.setVisible(Component.java:1623)
    at java.awt.Window.setVisible(Window.java:1014)
    at xWing.GUIlogin.<init>(GUIlogin.java:107)
    at xWing.Driver.main(Driver.java:7)
Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: javax.swing.JPasswordField[,0,0,0x0,invalid,layout=javax.swing.plaf.basic.BasicTextUI$UpdateHandler,alignmentX=0.0,alignmentY=0.0,border=com.apple.laf.AquaTextFieldBorder@5910e440,flags=288,maximumSize=,minimumSize=,preferredSize=,caretColor=javax.swing.plaf.ColorUIResource[r=0,g=0,b=0],disabledTextColor=javax.swing.plaf.ColorUIResource[r=128,g=128,b=128],editable=true,margin=javax.swing.plaf.InsetsUIResource[top=0,left=0,bottom=0,right=0],selectedTextColor=com.apple.laf.AquaImageFactory$SystemColorProxy[r=0,g=0,b=0],selectionColor=com.apple.laf.AquaImageFactory$SystemColorProxy[r=164,g=205,b=255],columns=20,columnWidth=0,command=,horizontalAlignment=LEADING,echoChar=●] is not attached to a vertical group
    at javax.swing.GroupLayout.checkComponents(GroupLayout.java:1090)
    at javax.swing.GroupLayout.prepare(GroupLayout.java:1040)
    at javax.swing.GroupLayout.layoutContainer(GroupLayout.java:910)
    at java.awt.Container.layout(Container.java:1510)
    at java.awt.Container.doLayout(Container.java:1499)
    at java.awt.Container.validateTree(Container.java:1695)
    at java.awt.Container.validateTree(Container.java:1704)
    at java.awt.Container.validateTree(Container.java:1704)
    at java.awt.Container.validateTree(Container.java:1704)
    at java.awt.Container.validateTree(Container.java:1704)
    at java.awt.Container.validate(Container.java:1630)
    at java.awt.Window.dispatchEventImpl(Window.java:2744)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
    at java.awt.EventQueue.access0(EventQueue.java:97)
    at java.awt.EventQueue.run(EventQueue.java:709)
    at java.awt.EventQueue.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
    at java.awt.EventQueue.run(EventQueue.java:731)
    at java.awt.EventQueue.run(EventQueue.java:729)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

为什么会出现此错误，我该如何解决？

Resource 1：我将我的逻辑（即我用来决定哪个组应该是并行/顺序的网格逻辑）与此答案进行了比较，似乎是对的。
Resource 2

Answer 1

看看这个：

            .addGroup(layout.createSequentialGroup()
                .addComponent(passwordLabel)
                .addComponent(passwordLabel)
                )

看起来不对。为什么要添加两次标签？

如果其中之一应该是 passwordField，这可以解释为什么异常说有一个 PasswordText 对象未附加到垂直组。

Answer 2

JPasswordField ... is not attached to a vertical group说的很清楚，不属于垂直组

你这里有错字：

        .addGroup(layout.createSequentialGroup()
            .addComponent(passwordLabel)
            .addComponent(passwordLabel)
            )

使用组布局可能会很棘手。以我的经验，我发现将第 3 方布局管理器用于 Swing 应用程序非常好 MigLayout 它有大量文档并且非常易于使用。试试吧。

为什么我的 GroupLayout 出现 'exception in main' 错误？

Why is my GroupLayout giving an 'exception in main' error?

java

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