JavaFX - UI 控件

UI 控件是允许用户与应用程序或网站交互的图形元素。它们包括按钮、菜单、滑块、文本字段、复选框、单选按钮等等。在本教程中，我们将探讨 JavaFX 的不同类型的 UI 控件。

让我们从介绍用户界面的三个主要方面开始讨论：

• UI 元素 - 这些是用户最终看到并与之交互的核心可视元素。JavaFX 提供了大量常用元素，从基本元素到复杂元素，我们将在本教程中介绍这些元素。

• 布局 - 它们定义了 UI 元素如何在屏幕上组织，并为 GUI（图形用户界面）提供最终的外观和感觉。这部分内容将在布局章节中介绍。

• 行为 - 这些是用户与 UI 元素交互时发生的事件。这部分内容将在事件处理章节中介绍。

要创建 GUI 组件（控件），JavaFX 支持多种控件，例如日期选择器、按钮文本字段等。这些控件由包 **javafx.scene.control** 的不同类表示。我们可以通过实例化其相应的类来创建控件。

以下是设计 JavaFX 中 GUI 时常用的控件列表。

示例

下面的程序是一个示例，它在 JavaFX 中显示一个登录页面。在这里，我们使用 **标签、文本字段、密码字段** 和 **按钮** 控件。将此代码保存在名为 **LoginPage.java** 的文件中。

import javafx.application.Application; 
import javafx.geometry.Insets; 
import javafx.geometry.Pos; 
import javafx.scene.Scene; 
import javafx.scene.control.Button; 
import javafx.scene.control.PasswordField; 
import javafx.scene.layout.GridPane; 
import javafx.scene.text.Text; 
import javafx.scene.control.TextField; 
import javafx.stage.Stage;  
         
public class LoginPage extends Application { 
   @Override 
   public void start(Stage stage) {      
      //creating label email 
      Text text1 = new Text("Email");       
      
      //creating label password 
      Text text2 = new Text("Password"); 
       
      //Creating Text Filed for email        
      TextField textField1 = new TextField();       
      
      //Creating Text Filed for password        
      PasswordField textField2 = new PasswordField();  
       
      //Creating Buttons 
      Button button1 = new Button("Submit"); 
      Button button2 = new Button("Clear");  
      
      //Creating a Grid Pane 
      GridPane gridPane = new GridPane();    
      
      //Setting size for the pane 
      gridPane.setMinSize(400, 200); 
      
      //Setting the padding  
      gridPane.setPadding(new Insets(10, 10, 10, 10)); 
      
      //Setting the vertical and horizontal gaps between the columns 
      gridPane.setVgap(5); 
      gridPane.setHgap(5);       
      
      //Setting the Grid alignment 
      gridPane.setAlignment(Pos.CENTER); 
       
      //Arranging all the nodes in the grid 
      gridPane.add(text1, 0, 0); 
      gridPane.add(textField1, 1, 0); 
      gridPane.add(text2, 0, 1);       
      gridPane.add(textField2, 1, 1); 
      gridPane.add(button1, 0, 2); 
      gridPane.add(button2, 1, 2); 
      gridPane.setStyle("-fx-background-color: BEIGE;"); 
       
      //Creating a scene object 
      Scene scene = new Scene(gridPane); 
       
      //Setting title to the Stage 
      stage.setTitle("CSS Example"); 
         
      //Adding scene to the stage 
      stage.setScene(scene);
      
      //Displaying the contents of the stage 
      stage.show(); 
   }      
   public static void main(String args[]){ 
      launch(args); 
   } 
}

使用以下命令从命令提示符编译并执行保存的 java 文件。

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

输出

执行后，上述程序将生成如下所示的 JavaFX 窗口。

示例

下面的程序是一个注册表单的示例，它演示了 JavaFX 中的控件，例如 **日期选择器、单选按钮、切换按钮、复选框、列表视图和选择列表**。将此代码保存在名为 **Registration.java** 的文件中。

import javafx.application.Application; 
import javafx.collections.FXCollections; 
import javafx.collections.ObservableList; 
import javafx.geometry.Insets; 
import javafx.geometry.Pos; 
import javafx.scene.Scene; 
import javafx.scene.control.Button; 
import javafx.scene.control.CheckBox; 
import javafx.scene.control.ChoiceBox; 
import javafx.scene.control.DatePicker; 
import javafx.scene.control.ListView; 
import javafx.scene.control.RadioButton; 
import javafx.scene.layout.GridPane; 
import javafx.scene.text.Text; 
import javafx.scene.control.TextField; 
import javafx.scene.control.ToggleGroup;  
import javafx.scene.control.ToggleButton; 
import javafx.stage.Stage; 
         
public class Registration extends Application { 
   @Override 
   public void start(Stage stage) {    
      //Label for name 
      Text nameLabel = new Text("Name"); 
      
      //Text field for name 
      TextField nameText = new TextField(); 
       
      //Label for date of birth 
      Text dobLabel = new Text("Date of birth"); 
      
      //date picker to choose date 
      DatePicker datePicker = new DatePicker(); 
       
      //Label for gender
      Text genderLabel = new Text("gender"); 
      
      //Toggle group of radio buttons       
      ToggleGroup groupGender = new ToggleGroup(); 
      RadioButton maleRadio = new RadioButton("male"); 
      maleRadio.setToggleGroup(groupGender); 
      RadioButton femaleRadio = new RadioButton("female"); 
      femaleRadio.setToggleGroup(groupGender); 
       
      //Label for reservation 
      Text reservationLabel = new Text("Reservation"); 
      
      //Toggle button for reservation 
      ToggleButton Reservation = new ToggleButton(); 
      ToggleButton yes = new ToggleButton("Yes"); 
      ToggleButton no = new ToggleButton("No"); 
      ToggleGroup groupReservation = new ToggleGroup(); 
      yes.setToggleGroup(groupReservation);   
      no.setToggleGroup(groupReservation); 
       
      //Label for technologies known 
      Text technologiesLabel = new Text("Technologies Known"); 
      
      //check box for education 
      CheckBox javaCheckBox = new CheckBox("Java"); 
      javaCheckBox.setIndeterminate(false); 
      
      //check box for education 
      CheckBox dotnetCheckBox = new CheckBox("DotNet"); 
      javaCheckBox.setIndeterminate(false); 
       
      //Label for education 
      Text educationLabel = new Text("Educational qualification"); 
      
      //list View for educational qualification 
      ObservableList<String> names = FXCollections.observableArrayList( 
         "Engineering", "MCA", "MBA", "Graduation", "MTECH", "Mphil", "Phd"); 
      ListView<String> educationListView = new ListView<String>(names); 
      
      //Label for location 
      Text locationLabel = new Text("location"); 
      
      //Choice box for location 
      ChoiceBox locationchoiceBox = new ChoiceBox(); 
      locationchoiceBox.getItems().addAll
         ("Hyderabad", "Chennai", "Delhi", "Mumbai", "Vishakhapatnam"); 
       
      //Label for register 
      Button buttonRegister = new Button("Register");  
      
      //Creating a Grid Pane 
      GridPane gridPane = new GridPane();    
      
      //Setting size for the pane 
      gridPane.setMinSize(500, 500); 
       
      //Setting the padding    
      gridPane.setPadding(new Insets(10, 10, 10, 10));  
      
      //Setting the vertical and horizontal gaps between the columns 
      gridPane.setVgap(5); 
      gridPane.setHgap(5);       
      
      //Setting the Grid alignment 
      gridPane.setAlignment(Pos.CENTER); 
       
      //Arranging all the nodes in the grid 
      gridPane.add(nameLabel, 0, 0); 
      gridPane.add(nameText, 1, 0); 
       
      gridPane.add(dobLabel, 0, 1);       
      gridPane.add(datePicker, 1, 1); 
      
      gridPane.add(genderLabel, 0, 2); 
      gridPane.add(maleRadio, 1, 2);       
      gridPane.add(femaleRadio, 2, 2); 
      gridPane.add(reservationLabel, 0, 3); 
      gridPane.add(yes, 1, 3);       
      gridPane.add(no, 2, 3);  
       
      gridPane.add(technologiesLabel, 0, 4); 
      gridPane.add(javaCheckBox, 1, 4);       
      gridPane.add(dotnetCheckBox, 2, 4);  
       
      gridPane.add(educationLabel, 0, 5); 
      gridPane.add(educationListView, 1, 5);      
       
      gridPane.add(locationLabel, 0, 6); 
      gridPane.add(locationchoiceBox, 1, 6);    
       
      gridPane.add(buttonRegister, 2, 8);      
      
      //Styling nodes   
      buttonRegister.setStyle(
         "-fx-background-color: darkslateblue; -fx-textfill: white;"); 
       
      nameLabel.setStyle("-fx-font: normal bold 15px 'serif' "); 
      dobLabel.setStyle("-fx-font: normal bold 15px 'serif' "); 
      genderLabel.setStyle("-fx-font: normal bold 15px 'serif' "); 
      reservationLabel.setStyle("-fx-font: normal bold 15px 'serif' "); 
      technologiesLabel.setStyle("-fx-font: normal bold 15px 'serif' "); 
      educationLabel.setStyle("-fx-font: normal bold 15px 'serif' "); 
      locationLabel.setStyle("-fx-font: normal bold 15px 'serif' "); 
       
      //Setting the back ground color 
      gridPane.setStyle("-fx-background-color: BEIGE;");       
       
      //Creating a scene object 
      Scene scene = new Scene(gridPane); 
      
      //Setting title to the Stage 
      stage.setTitle("Registration Form"); 
         
      //Adding scene to the stage 
      stage.setScene(scene);  
      
      //Displaying the contents of the stage 
      stage.show(); 
   }      
   public static void main(String args[]){ 
      launch(args); 
   } 
}

使用以下命令从命令提示符编译并执行保存的 java 文件。

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

输出

执行后，上述程序将生成如下所示的 JavaFX 窗口。