Javafx 简明教程

JavaFX - Button Bar

ButtonBar 是用水平布局排列按钮的容器类型。这些按钮的排列或位置取决于我们正在使用的操作系统。通常，放置在 ButtonBar 中的所有按钮都统一大小。然而，它还允许我们自定义按钮的大小和位置。一个典型的按钮栏如图所示。它包含两个按钮，分别为“是”和“否”。

A ButtonBar is a type of container that arranges buttons in a horizontal layout. The arrangement or positions of these buttons depend on the type of operating system we are working on. Generally, all the buttons placed inside a ButtonBar are uniformly sized. However, it also allows us to customize the size as well as positions of the buttons. A typical button bar looks like the below figure. It contains two buttons namely "Yes" and "No".

button bar sample

ButtonBar in JavaFX

在 JavaFX 中，名为 ButtonBar 的类表示一个按钮栏。此类属于包 javafx.scene.control 。我们可以通过实例化 ButtonBar 类在 JavaFX 中创建按钮栏节点。

In JavaFX, the class named ButtonBar represents a button bar. This class belongs to the package javafx.scene.control. We can create a button bar node in JavaFX by instantiating the ButtonBar class.

这个类提供了两个构造器，如下所示 −

There are two constructors available for this class, and they are as follows −

  1. ButtonBar() − It is used for creating a button bar with default properties that will be specific to the operating system.

  2. ButtonBar(String buttonOrder) − It will create a button bar with the specified button order.

Steps to create a Button Bar in JavaFX

要在 JavaFX 中创建按钮栏，请执行以下步骤。

To create a Button Bar in JavaFX, follow the steps given below.

Step 1: Create two or more Buttons

在 JavaFX 中，通过实例化名为 Button 的类（该类属于包 javafx.scene.control ）来创建按钮。像下面那样实例化此类 −

In JavaFX, the buttons are created by instantiating the class named Button which belongs to a package javafx.scene.control. Instantiate this class as shown below −

//Creating required buttons
Button buttonOne = new Button("Back");
Button buttonTwo = new Button("Accept");
Button buttonThree = new Button("Cancel");

同样，为项目创建所需数量的按钮。

Similarly, create the required number of buttons for the project.

Step 2: Instantiate ButtonBar class

实例化包 javafx.scene.control 的 ButtonBar 类，不清向其构造器传递任何参数值，并使用 getButtons() 方法添加所有按钮。

Instantiate the ButtonBar class of package javafx.scene.control without passing any parameter value to its constructor and add all the buttons using the getButtons() method.

//Creating a ButtonBar
ButtonBar newButtonbar = new ButtonBar();
// Adding buttons to the ButtonBar
newButtonbar.getButtons().addAll(buttonOne, buttonTwo, buttonThree);

Step 3: Launching Application

创建按钮栏后，按照以下步骤来正确启动应用程序 −

After creating the button bar, follow the given steps below to launch the application properly −

  1. Firstly, instantiate the class named HBox and add the button bar using getChildren() method.

  2. Then, instantiate the class named Scene by passing the HBox object as a parameter value to its constructor. We can also pass dimensions of the application screen as optional parameters to this constructor.

  3. Then, set the title to the stage using the setTitle() method of the Stage class.

  4. Now, a Scene object is added to the stage using the setScene() method of the class named Stage.

  5. Display the contents of the scene using the method named show().

  6. Lastly, the application is launched with the help of the launch() method.

Example

以下是将在 JavaFX 中创建一个按钮栏的程序。将此代码保存在名为 JavafxButtonBar.java 的文件中。

Following is the program which will create a button bar in JavaFX. Save this code in a file with the name JavafxButtonBar.java.

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.ButtonBar;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
public class JavafxButtonBar extends Application {
   @Override
   public void start(Stage stage) {
      //Creating required buttons
      Button buttonOne = new Button("Back");
      Button buttonTwo = new Button("Accept");
      Button buttonThree = new Button("Cancel");
      //Creating a ButtonBar
      ButtonBar newButtonbar = new ButtonBar();
      // Adding buttons to the ButtonBar
      newButtonbar.getButtons().addAll(buttonOne, buttonTwo, buttonThree);
      newButtonbar.setPadding(new Insets(10));
      HBox box = new HBox();
      box.getChildren().addAll(newButtonbar);
      //Setting the stage
      Scene scene = new Scene(box, 500, 250);
      stage.setTitle("ButtonBar in JavaFX");
      stage.setScene(scene);
      stage.show();
   }
   public static void main(String args[]) {
      launch(args);
   }
}

使用以下命令通过命令提示符编译并执行上述 Java 文件。

Compile and execute the above Java file using the command prompt with the help of following commands.

javac --module-path %PATH_TO_FX% --add-modules javafx.controls JavafxButtonBar.java
java --module-path %PATH_TO_FX% --add-modules javafx.controls JavafxButtonBar

在执行时，上述程序将生成一个 JavaFX 窗口，其中显示了如图所示的 ButtonBar。

On executing, the above program generates a JavaFX window displaying a ButtonBar as shown below.

buttonbar output

Creating a ButtonBar with customized Button orders

在大多数情况下，Button 的顺序由操作系统决定。但是，如果需要自定义布局，则可以使用 ButtonBar 类的 setButtonOrder() 方法。它将按钮顺序属性作为参数，并相应地排列按钮。不同操作系统的按钮顺序属性为 BUTTON_ORDER_WINDOWS、BUTTON_ORDER_MAC_OS 和 BUTTON_ORDER_LINUX。

In most cases, the order of the Buttons is determined by the operating system. But, if a custom layout is required, then, the setButtonOrder() method of the ButtonBar class can be used. It takes button order property as a parameter and arranges the buttons accordingly. The button order properties of different OS are BUTTON_ORDER_WINDOWS, BUTTON_ORDER_MAC_OS, and BUTTON_ORDER_LINUX.

Example

在以下 JavaFX 程序中，我们将通过设置 MAC 的按钮顺序属性来创建一个 ButtonBar。将此代码保存在名为 JavafxButtonBar.java 的文件中。

In the following JavaFX program, we will create a ButtonBar by setting the button order property of MAC. Save this code in a file with the name JavafxButtonBar.java.

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.ButtonBar;
import javafx.scene.control.ButtonBar.ButtonData;
import javafx.scene.control.Button;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;
public class JavafxButtonBar extends Application {
   @Override
   public void start(Stage stage) {
      //Creating required buttons
      Button buttonTwo = new Button("Yes");
      Button buttonOne = new Button("No");
      //Creating a ButtonBar
      ButtonBar newButtonbar = new ButtonBar();
      // Setting the order of Buttons
      newButtonbar.setButtonOrder("BUTTON_ORDER_MAC_OS");
      // Adding buttons to the ButtonBar
      newButtonbar.getButtons().addAll(buttonOne, buttonTwo);
      newButtonbar.setPadding(new Insets(10));
      HBox box = new HBox();
      box.getChildren().addAll(newButtonbar);
      //Setting the stage
      Scene scene = new Scene(box, 500, 250);
      stage.setTitle("ButtonBar in JavaFX");
      stage.setScene(scene);
      stage.show();
   }
   public static void main(String args[]) {
      launch(args);
   }
}

使用以下命令从命令提示符处编译并执行已保存的 Java 文件。

Compile and execute the saved Java file from the command prompt using the following commands.

javac --module-path %PATH_TO_FX% --add-modules javafx.controls JavafxButtonBar.java
java --module-path %PATH_TO_FX% --add-modules javafx.controls JavafxButtonBar

当我们执行上述代码时，它将生成以下输出。

When we execute the above code, it will generate the following output.

button bar output2