JavaFX密码字段不起作用

1 回答

• 1

  Issues with your code

  @FXML 是控制器实例的注入注释，不应将其与 static 成员或使用 new 关键字初始化的成员一起使用 .

  相反，控制器中的定义应该是：

  @FXML private PasswordField passwordBox;
  

  Additional considerations which may or may not apply in your case

  • 控制器实例应始终通过新的FXMLLoader（） . load（...）调用创建（不要通过控制器本身的 new 关键字创建，除非您随后使用loader.setController()） .

  • fxml文件必须指定密码字段的名称，该名称与控制器中的名称相匹配（在您的情况下，此名称为 passwordBox ） .

  Example

  GatewayApplication.java

  package application;
  
  import javafx.application.Application;
  import javafx.fxml.FXMLLoader;
  import javafx.scene.Scene;
  import javafx.scene.layout.AnchorPane;
  import javafx.stage.Stage;
  
  import java.io.IOException;
  
  public class GatewayApplication extends Application {
      public static void main(String[] args) {
          launch(args);
      }
  
      @Override
      public void start(Stage stage) throws IOException {
          FXMLLoader loader = new FXMLLoader(getClass().getResource("passport.fxml"));
          AnchorPane layout = loader.load();
          stage.setScene(new Scene(layout));
          stage.show();
      }
  }
  

  MainController.java

  由SceneBuilder View | Show Sample Skeleton 生成 .

  package application;
  
  import java.net.URL;
  import java.util.ResourceBundle;
  import javafx.event.ActionEvent;
  import javafx.fxml.FXML;
  import javafx.scene.control.Button;
  import javafx.scene.control.Label;
  import javafx.scene.control.PasswordField;
  import javafx.scene.control.TextField;
  import javafx.scene.image.ImageView;
  import javafx.scene.input.MouseEvent;
  import javafx.scene.layout.AnchorPane;
  
  
  public class MainController {
  
      @FXML
      private ResourceBundle resources;
  
      @FXML
      private URL location;
  
      @FXML
      private Button connectButton;
  
      @FXML
      private ImageView favoritesButton;
  
      @FXML
      private AnchorPane mainAnchor;
  
      @FXML
      private PasswordField passwordBox;
  
      @FXML
      private Label passwordLbl;
  
      @FXML
      private TextField portBox;
  
      @FXML
      private Label portLbl;
  
      @FXML
      private TextField serverIPBox;
  
      @FXML
      private Label serverIPLbl;
  
      @FXML
      private ImageView settingsButton;
  
      @FXML
      private TextField usernameBox;
  
      @FXML
      private Label usernameLbl;
  
  
      @FXML
      void connectClicked(ActionEvent event) {
          System.out.println("password = " + passwordBox.getText());
      }
  
      @FXML
      void favoritesClicked(MouseEvent event) {
      }
  
      @FXML
      void settingsClicked(MouseEvent event) {
      }
  
      @FXML
      void initialize() {
          assert connectButton != null : "fx:id=\"connectButton\" was not injected: check your FXML file 'passport.fxml'.";
          assert favoritesButton != null : "fx:id=\"favoritesButton\" was not injected: check your FXML file 'passport.fxml'.";
          assert mainAnchor != null : "fx:id=\"mainAnchor\" was not injected: check your FXML file 'passport.fxml'.";
          assert passwordBox != null : "fx:id=\"passwordBox\" was not injected: check your FXML file 'passport.fxml'.";
          assert passwordLbl != null : "fx:id=\"passwordLbl\" was not injected: check your FXML file 'passport.fxml'.";
          assert portBox != null : "fx:id=\"portBox\" was not injected: check your FXML file 'passport.fxml'.";
          assert portLbl != null : "fx:id=\"portLbl\" was not injected: check your FXML file 'passport.fxml'.";
          assert serverIPBox != null : "fx:id=\"serverIPBox\" was not injected: check your FXML file 'passport.fxml'.";
          assert serverIPLbl != null : "fx:id=\"serverIPLbl\" was not injected: check your FXML file 'passport.fxml'.";
          assert settingsButton != null : "fx:id=\"settingsButton\" was not injected: check your FXML file 'passport.fxml'.";
          assert usernameBox != null : "fx:id=\"usernameBox\" was not injected: check your FXML file 'passport.fxml'.";
          assert usernameLbl != null : "fx:id=\"usernameLbl\" was not injected: check your FXML file 'passport.fxml'.";
      }
  
  }
  

  style.css文件

  .root {
      -fx-background-color: cornsilk;
  }
  

  passport.fxml

  <?xml version="1.0" encoding="UTF-8"?>
  
  <?import javafx.scene.control.*?>
  <?import javafx.scene.image.Image?>
  <?import javafx.scene.image.ImageView?>
  <?import javafx.scene.layout.AnchorPane?>
  <?import javafx.scene.text.Font?>
  <?import java.net.URL?>
  <AnchorPane fx:id="mainAnchor" opacity="1.0" prefHeight="200.0" prefWidth="408.0000999999975" styleClass="back" xmlns:fx="http://javafx.com/fxml" fx:controller="application.MainController">
      <children>
          <Label fx:id="serverIPLbl" layoutX="14.0" layoutY="28.0" prefWidth="175.0" text="Server IP">
              <font>
                  <Font name="Segoe UI" size="12.0" fx:id="x1" />
              </font>
          </Label>
          <TextField fx:id="serverIPBox" layoutX="14.0" layoutY="50.0" prefWidth="175.0" />
          <Label fx:id="portLbl" font="$x1" layoutX="215.0" layoutY="28.0" prefWidth="175.0" text="Port" />
          <TextField fx:id="portBox" layoutX="215.0" layoutY="50.0" prefWidth="175.0" />
          <Label fx:id="passwordLbl" font="$x1" layoutX="14.0" layoutY="81.0" prefWidth="175.0" text="Server Password" />
          <ImageView fx:id="settingsButton" fitHeight="23.0" fitWidth="23.0" layoutX="14.0" layoutY="137.0" onMouseClicked="#settingsClicked" pickOnBounds="true" preserveRatio="true">
              <image>
                  <Image url="http://icons.iconarchive.com/icons/hopstarter/soft-scraps/24/Gear-icon.png" />
              </image>
          </ImageView>
          <Button id="startServer" fx:id="connectButton" layoutX="14.0" layoutY="167.0" mnemonicParsing="false" onAction="#connectClicked" prefHeight="22.0" prefWidth="376.0" text="Connect" />
          <Label fx:id="usernameLbl" font="$x1" layoutX="215.0" layoutY="81.0" prefWidth="175.0" text="Username" />
          <TextField id="serverIPBox" fx:id="usernameBox" layoutX="215.0" layoutY="103.0" prefWidth="175.0" promptText="a-z A-Z 0-9 _ - chars allowed" />
          <ImageView id="favoriteButton" fx:id="favoritesButton" fitHeight="23.0" fitWidth="23.0" layoutX="55.0" layoutY="137.0" onMouseClicked="#favoritesClicked" pickOnBounds="true" preserveRatio="true">
              <image>
                  <Image url="http://icons.iconarchive.com/icons/hopstarter/soft-scraps/24/Button-Favorite-icon.png"/>
              </image>
          </ImageView>
          <PasswordField fx:id="passwordBox" layoutX="14.0" layoutY="103.0" prefWidth="175.0" promptText="Optional" />
      </children>
      <stylesheets>
          <URL value="@style.css" />
      </stylesheets>
  </AnchorPane>
  

  示例程序UI

  

  示例程序输出

  在密码字段中输入魔术作品“xyzzy”并按下连接后，程序将从字段中提取密码并将其打印到控制台：

  password = xyzzy
  

  ---

  使用的测试系统是运行Java 8b121的OS X 10.9 .

  在将来的这类问题中，您可能需要提供minimal, complete, tested and readable example . 所有问题都不需要这样的样本，但肯定会对此有所帮助 .

  回复于 2024-05-03T11:22:33+08:00