How to Use Tabbed Panes如何使用选项卡式窗格

With the JTabbedPane class, you can have several components, such as panels, share the same space. 使用JTabbedPane类，可以让多个组件（如面板）共享相同的空间。The user chooses which component to view by selecting the tab corresponding to the desired component. 用户通过选择与所需组件相对应的选项卡来选择要查看的组件。If you want similar functionality without the tab interface, you can use a card layout instead of a tabbed pane.如果您想要类似的功能而不需要选项卡界面，可以使用卡片布局而不是选项卡式窗格。

To Create Tabbed Panes创建选项卡式窗格的步骤

To create a tabbed pane, instantiate JTabbedPane, create the components you wish it to display, and then add the components to the tabbed pane using the addTab method.要创建选项卡式窗格，请实例化JTabbedPane，创建希望它显示的组件，然后使用addTab方法将组件添加到选项卡式窗格。

The following picture introduces an application called TabbedPaneDemo that has a tabbed pane with four tabs.下图介绍了一个名为TabbedPaneDemo的应用程序，它有一个带有四个选项卡的选项卡式窗格。

As the TabbedPaneDemo example shows, a tab can have a tool tip and a mnemonic, and it can display both text and an image.如TabbedPaneDemo示例所示，选项卡可以具有工具提示和助记符，并且可以显示文本和图像。

Tab Placement标签放置

The default tab placement is set to the TOP location, as shown above. 默认选项卡放置设置为TOP位置，如上所示。You can change the tab placement to LEFT, RIGHT, TOP or BOTTOM by using the setTabPlacement method.可以使用setTabPlacement方法将选项卡放置更改为LEFT、RIGHT、TOP或BOTTOM。

Code for Tabbed Panes选项卡式窗格的代码

The following code from TabbedPaneDemo.java creates the tabbed pane in the previous example. TabbedPaneDemo.java中的以下代码在前面的示例中创建了选项卡式窗格。Note that no event-handling code is necessary. 请注意，不需要事件处理代码。The JTabbedPane object takes care of mouse and keyboard events for you.JTabbedPane对象为您处理鼠标和键盘事件。

JTabbedPane tabbedPane = new JTabbedPane();
ImageIcon icon = createImageIcon("images/middle.gif");

JComponent panel1 = makeTextPanel("Panel #1");
tabbedPane.addTab("Tab 1", icon, panel1,
                  "Does nothing");
tabbedPane.setMnemonicAt(0, KeyEvent.VK_1);

JComponent panel2 = makeTextPanel("Panel #2");
tabbedPane.addTab("Tab 2", icon, panel2,
                  "Does twice as much nothing");
tabbedPane.setMnemonicAt(1, KeyEvent.VK_2);

JComponent panel3 = makeTextPanel("Panel #3");
tabbedPane.addTab("Tab 3", icon, panel3,
                  "Still does nothing");
tabbedPane.setMnemonicAt(2, KeyEvent.VK_3);

JComponent panel4 = makeTextPanel(
        "Panel #4 (has a preferred size of 410 x 50).");
panel4.setPreferredSize(new Dimension(410, 50));
tabbedPane.addTab("Tab 4", icon, panel4,
                      "Does nothing at all");
tabbedPane.setMnemonicAt(3, KeyEvent.VK_4);

As the previous code shows, the addTab method handles the bulk of the work in setting up a tab in a tabbed pane. 正如前面的代码所示，addTab方法处理了在选项卡式窗格中设置选项卡的大部分工作。The addTab method has several forms, but they all use both a string title and the component to be displayed by the tab. addTab方法有几种形式，但它们都使用字符串标题和选项卡显示的组件。Optionally, you can specify an icon and tool tip string. 或者，可以指定图标和工具提示字符串。The text or icon (or both) can be null. 文本或图标（或两者）可以为空。Another way to create a tab is to use the insertTab method, which lets you specify the index of the tab you're adding. 创建选项卡的另一种方法是使用insertTab方法，该方法允许您指定要添加的选项卡的索引。Note that the addTab method does not allow index specification in this step.注意，addTab方法不允许在此步骤中指定索引。

To Switch to Specific Tabs切换到特定选项卡

There are three ways to switch to specific tabs using GUI.使用GUI切换到特定选项卡有三种方法。

1. Using a mouse.使用鼠标。 To switch to a specific tab, the user clicks it with the mouse.要切换到特定选项卡，用户用鼠标单击它。
2. Using keyboard arrows.使用键盘箭头。 When the JTabbedPane object has the focus, the keyboard arrows can be used to switch from tab to tab.当JTabbedPane对象具有焦点时，可以使用键盘箭头在选项卡之间切换。
3. Using key mnemonics.使用键助记符。 The setMnemonicAt method allows the user to switch to a specific tab using the keyboard. setMnemonicAt方法允许用户使用键盘切换到特定选项卡。For example, setMnemonicAt(3, KeyEvent.VK_4) makes '4' the mnemonic for the fourth tab (which is at index 3, since the indices start with 0); pressing Alt-4 makes the fourth tab's component appear. 例如，setMnemonicAt(3, KeyEvent.VK_4)使“4”成为第四个选项卡的助记符（即索引3处，因为索引从0开始）；按Alt-4将显示第四个选项卡的组件。Often, a mnemonic uses a character in the tab's title that is then automatically underlined.通常，助记符在标签标题中使用一个字符，然后自动加下划线。

To switch to a specific tab programmatically, use the setSelectedIndex or the setSelectedComponent methods.要以编程方式切换到特定选项卡，请使用setSelectedIndex方法或setSelectedComponent组件方法。

Preferred Size in Tabs标签中的首选大小

When building components to add to a tabbed pane, keep in mind that no matter which child of a tabbed pane is visible, each child gets the same amount of space in which to display itself. 在构建要添加到选项卡式窗格的组件时，请记住，无论选项卡式窗格中的哪个子项可见，每个子项都会获得相同的空间量来显示自己。The preferred size of the tabbed pane is just big enough to display its tallest child at its preferred height, and its widest child at its preferred width. 选项卡式窗格的首选大小刚好足以在其首选高度显示其最高子级，并在其首选宽度显示其最宽子级。Similarly, the minimum size of the tabbed pane depends on the biggest minimum width and height of all its children.类似地，选项卡式窗格的最小大小取决于其所有子项的最大最小宽度和高度。

In the TabbedPaneDemo example, the fourth panel has a preferred width and height that are larger than those of the other panels. 在TabbedPaneDemo示例中，第四个面板的首选宽度和高度大于其他面板的宽度和高度。Thus, the preferred size of the tabbed pane is just big enough to display the fourth panel at its preferred size. 因此，选项卡式窗格的首选大小刚好足以以其首选大小显示第四个面板。Every panel gets exactly the same amount of space — 410 pixels wide and 50 high, assuming the tabbed pane is at its preferred size. 每个面板获得完全相同的空间量；410像素宽和50像素高，假设选项卡式窗格处于其优选大小。If you do not understand how preferred size is used, please refer to How Layout Management Works.如果您不了解如何使用首选尺寸，请参阅布局管理的工作原理。

Tabs With Custom Components带有自定义组件的选项卡

The TabComponentsDemo example introduces a tabbed pane whose tabs contain real components. TabComponentsDemo示例引入了一个选项卡式窗格，其选项卡包含实际组件。The use of custom components brings new features such as buttons, combo boxes, labels and other components to tabs, and allows more complex user interaction.自定义组件的使用为选项卡带来了新功能，如按钮、组合框、标签和其他组件，并允许更复杂的用户交互。

Here is a tabbed pane with close buttons on its tabs.这是一个选项卡式窗格，其选项卡上有关闭按钮。

To Remove Tabs要删除选项卡：

The following code from ButtonTabComponent.java removes a tab from the tabbed pane. ButtonTabComponent.java中的以下代码从选项卡窗格中删除了一个选项卡。Note that event-handling code is necessary. 请注意，事件处理代码是必需的。Since each tab contains a real JButton object, you must attach an ActionListener to the close button. 由于每个选项卡都包含一个真实的JButton对象，因此必须将ActionListener附加到关闭按钮。As the user clicks the button, the actionPerformed method determines the index of the tab it belongs to and removes the corresponding tab.当用户单击按钮时，actionPerformed方法确定其所属选项卡的索引，并删除相应的选项卡。

public void actionPerformed(ActionEvent e) {
int i = pane.indexOfTabComponent(ButtonTabComponent.this);
    if (i != -1) {
    pane.remove(i);
    }
}

To Give Titles to Customized Tabs为自定义选项卡提供标题

The code below, taken from ButtonTabComponent.java, shows how a customized tab component gets a title from an original tabbed pane tab.下面的代码取自ButtonTabComponent.java，显示了自定义选项卡组件如何从原始选项卡窗格选项卡获取标题。

JLabel label = new JLabel(title) {
    public String getText() {
        int i = pane.indexOfTabComponent(ButtonTabComponent.this);
        if (i != -1) {
            return pane.getTitleAt(i);
        }
        return null;
    }
};

The Tabbed Pane API选项卡式窗格API

The following tables list the commonly used JTabbedPane constructors and methods. 下表列出了常用的JTabbedPane构造函数和方法。The API for using tabbed panes falls into the following categories:使用选项卡式窗格的API分为以下几类：

• Creating and Setting Up a Tabbed Pane创建和设置选项卡式窗格
• Inserting, Removing, Finding, and Selecting Tabs插入、删除、查找和选择选项卡
• Changing Tab Appearance更改选项卡外观
• Setting Up Custom Components on Tabs在选项卡上设置自定义组件

Examples That Use Tabbed Panes使用选项卡式窗格的示例

This table lists examples that use JTabbedPane and points to where those examples are described.下表列出了使用JTabbedPane的示例，并指出了这些示例的描述位置。