How to Use Internal Frames如何使用内部框架

With the JInternalFrame class you can display a JFrame-like window within another window. 使用JInternalFrame类，您可以在另一个窗口中显示类似JFrame的窗口。Usually, you add internal frames to a desktop pane. 通常，将内部框架添加到桌面窗格。The desktop pane, in turn, might be used as the content pane of a JFrame. 反过来，桌面窗格可以用作JFrame的内容窗格。The desktop pane is an instance of JDesktopPane, which is a subclass of JLayeredPane that has added API for managing multiple overlapping internal frames.桌面窗格是JDesktopPane的一个实例，它是JLayeredPane的子类，添加了用于管理多个重叠内部帧的API。

You should consider carefully whether to base your program's GUI around frames or internal frames. Switching from internal frames to frames or vice versa is not necessarily a simple task. 您应该仔细考虑程序的GUI是基于框架还是基于内部框架。从内部帧切换到帧或从内部帧转换到帧不一定是一项简单的任务。By experimenting with both frames and internal frames, you can get an idea of the tradeoffs involved in choosing one over the other.通过对框架和内部框架进行实验，您可以了解选择一个框架而不是另一个框架所涉及的权衡。

Here is a picture of an application that has two internal frames (one of which is iconified) inside a regular frame:以下是一个应用程序的图片，该应用程序在一个常规框架内有两个内部框架（其中一个是图标化的）：

The following code, taken from InternalFrameDemo.java, creates the desktop and internal frames in the previous example.下面的代码取自InternalFrameDemo.java，在前面的示例中创建桌面和内部框架。

...//In the constructor of InternalFrameDemo, a JFrame subclass:
    desktop = new JDesktopPane();
    createFrame(); //Create first window
    setContentPane(desktop);
    ...
    //Make dragging a little faster but perhaps uglier.
    desktop.setDragMode(JDesktopPane.OUTLINE_DRAG_MODE);
...
protected void createFrame() {
    MyInternalFrame frame = new MyInternalFrame();
    frame.setVisible(true);
    desktop.add(frame);
    try {
        frame.setSelected(true);
    } catch (java.beans.PropertyVetoException e) {}
}

...//In the constructor of MyInternalFrame, a JInternalFrame subclass:
static int openFrameCount = 0;
static final int xOffset = 30, yOffset = 30;

public MyInternalFrame() {
    super("Document #" + (++openFrameCount),
          true, //resizable
          true, //closable
          true, //maximizable
          true);//iconifiable
    //...Create the GUI and put it in the window...
    //...Then set the window size or call pack...
    ...
    //Set the window's location.
    setLocation(xOffset*openFrameCount, yOffset*openFrameCount);
}

Internal Frames vs. Regular Frames内部框架与常规框架

The code for using internal frames is similar in many ways to the code for using regular Swing frames. Because internal frames have root panes, setting up the GUI for a JInternalFrame is very similar to setting up the GUI for a JFrame. 使用内部框架的代码在许多方面与使用常规摆动框架的代码类似。由于内部框架具有根窗格，因此为JInternalFrame设置GUI与为JFrame设置图形用户界面非常相似。JInternalFrame also provides other API, such as pack, that makes it similar to JFrame.还提供了其他API，如pack，使其类似于JFrame。

Internal frames are not windows or top-level containers, however, which makes them different from frames. 但是，内部框架不是窗口或顶级容器，这使它们与框架不同。For example, you must add an internal frame to a container (usually a JDesktopPane); an internal frame cannot be the root of a containment hierarchy. 例如，必须将内部框架添加到容器（通常是JDesktopPane）；内部框架不能是包含层次结构的根。Also, internal frames do not generate window events. 此外，内部帧不生成窗口事件。Instead, the user actions that would cause a frame to fire window events cause an internal frame to fire internal frame events.相反，会导致帧触发窗口事件的用户操作会导致内部帧触发内部帧事件。

Because internal frames are implemented with platform-independent code, they add some features that frames cannot give you. 因为内部框架是用独立于平台的代码实现的，所以它们添加了一些框架无法提供的功能。One such feature is that internal frames give you more control over their state and capabilities than frames do. 一个这样的特性是，内部框架比框架更能控制它们的状态和功能。You can programmatically iconify or maximize an internal frame. 您可以以编程方式图标化或最大化内部框架。You can also specify what icon goes in the internal frame's title bar. 您还可以指定内部框架标题栏中的图标。You can even specify whether the internal frame has the window decorations to support resizing, iconifying, closing, and maximizing.您甚至可以指定内部框架是否具有支持调整大小、图标化、关闭和最大化的窗口装饰。

Another feature is that internal frames are designed to work within desktop panes. 另一个特点是，内部框架设计用于在桌面窗格中工作。The JInternalFrame API contains methods such as moveToFront that work only if the internal frame's container is a layered pane such as a JDesktopPane.JInternalFrame API包含moveToFront等方法，这些方法仅在内部框架的容器是分层窗格（如JDesktopPane）时才有效。

Rules of Using Internal Frames使用内部框架的规则

If you have built any programs using JFrame and the other Swing components, then you already know a lot about how to use internal frames. 如果您已经使用JFrame和其他Swing组件构建了任何程序，那么您已经知道了很多关于如何使用内部框架的知识。The following list summarizes the rules for using internal frames. 下表总结了使用内部框架的规则。For additional information, see How to Make Frames and The JComponent Class.有关其他信息，请参阅如何生成框架和JComponent类。

You must set the size of the internal frame.必须设置内部框架的大小。

If you do not set the size of the internal frame, it will have zero size and thus never be visible. 如果不设置内部框架的大小，则其大小将为零，因此永远不可见。You can set the size using one of the following methods: setSize, pack, or setBounds.可以使用以下方法之一设置大小：setSize、pack或setBounds。

As a rule, you should set the location of the internal frame.通常，应设置内部框架的位置。

If you do not set the location of the internal frame, it will come up at 0,0 (the upper left of its container). 如果不设置内部框架的位置，它将出现在0,0（其容器的左上角）。You can use the setLocation or setBounds method to specify the upper left point of the internal frame, relative to its container.可以使用setLocation或setBounds方法指定内部框架相对于其容器的左上点。

To add components to an internal frame, you add them to the internal frame's content pane.要将组件添加到内部框架，请将其添加到内部框的内容窗格中。

This is exactly like the JFrame situation. 这与JFrame的情况完全相同。See Adding Components to the Content Pane for details.有关详细信息，请参阅将组件添加到内容窗格。

Dialogs that are internal frames should be implemented using JOptionPane or JInternalFrame, not JDialog.作为内部框架的对话框应该使用JOptionPane或JInternalFrame实现，而不是JDialog。

To create a simple dialog, you can use the JOptionPane showInternalXxxDialog methods, as described in How to Make Dialogs.要创建一个简单的对话框，可以使用JOptionPane showInternalXxxDialog方法，如如何创建对话框中所述。

You must add an internal frame to a container.必须向容器添加内部框架。

If you do not add the internal frame to a container (usually a JDesktopPane), the internal frame will not appear.如果不将内部框架添加到容器（通常是JDesktopPane），则不会显示内部框架。

You need to call show or setVisible on internal frames.您需要在内部框架上调用show或setVisible。

Internal frames are invisible by default. 默认情况下，内部框架不可见。You must invoke setVisible(true) or show() to make them visible.必须调用setVisible(true)或show()使它们可见。

Internal frames fire internal frame events, not window events.内部帧触发内部帧事件，而不是窗口事件。

Handling internal frame events is almost identical to handling window events. 处理内部帧事件与处理窗口事件几乎相同。See How to Write an Internal Frame Listener for more information.有关详细信息，请参阅如何编写内部帧侦听器。

desktop.setDragMode(JDesktopPane.OUTLINE_DRAG_MODE);

The Internal Frame API内部框架API

The following tables list the commonly used JInternalFrame constructors and methods, as well as a few methods that JDesktopPane provides. 下表列出了常用的JInternalFrame构造函数和方法，以及JDesktopPane提供的一些方法。Besides the API listed in this section, JInternalFrame inherits useful API from its superclasses, JComponent, Component, and Container. 除了本节列出的API之外，JInternalFrame还从其超类JComponent、Component和Container继承了有用的API。See The JComponent Class for lists of methods from those classes.有关这些类的方法列表，请参阅JComponent类。

Like JInternalFrame, JDesktopPane descends from JComponent, and thus provides the methods described in The JComponent Class. 与JInternalFrame一样，JDesktopPane从JComponent派生，因此提供了JComponnt类中描述的方法。Because JDesktopPane extends JLayeredPane, it also supports the methods described in The Layered Pane API.因为JDesktopPane扩展了JLayeredPane，所以它还支持分层窗格API中描述的方法。

The API for using internal frames falls into these categories:使用内部框架的API分为以下几类：

• Creating the internal frame创建内部框架
• Adding components to the internal frame向内部框架添加组件
• Specifying the internal frame's visibility, size, and location指定内部框架的可见性、大小和位置
• Performing window operations on the internal frame在内部框架上执行窗口操作
• Controlling window decorations and capabilities控制窗口装饰和功能
• Using the JDesktopPane API使用JDesktopPane API

Examples that Use Internal Frames使用内部框架的示例

The following examples use internal frames. 以下示例使用内部框架。Because internal frames are similar to regular frames, you should also look at Examples that Use Frames.因为内部框架与常规框架类似，所以还应该查看使用框架的示例。