Question

我正在构建一个计算器，我需要为按钮执行常规事件处理程序。以下问题阻止了我：

我怎样才能使它只在按下按钮时才有效，而不是在窗外。
如何存储显示的值？
当我不止一次按1，它不会继续。它只维持1 数字，我需要像：111111

谢谢

这是我到目前为止所做的，但它不起作用：

scene.addEventFilter(MouseEvent.MOUSE_PRESSED, new EventHandler<MouseEvent>() {
            @Override
            public void handle(MouseEvent mouseEvent) {

                tres.pressedProperty().addListener((o, old, newValue) ->
                                       Result.setText("3"));

                DisplayingText = Result.getText();
                System.out.println(DisplayingText);

                if(Result.getText().equals("3"))
                {
                    System.out.println("mouse click detected! ");
                }
            }
        });

Answer 1

您可以使用按钮javafx.scene.control.Button对场景进行数字和操作。按下按钮的操作句柄如下：

button.setOnAction((ActionEvent e) -> {
   displayingText = result.getText();
});

Answer 2

此应用程序模拟了一个淡化计算器。它显示了如何使用TextField的{{1}}。它还演示了如何使用一个appendText来处理多个EventHandler。

主要

Nodes

FXML

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

/**
 *
 * @author blj0011
 */
public class WateredDownCalCulator extends Application
{

    @Override
    public void start(Stage stage) throws Exception
    {
        Parent root = FXMLLoader.load(getClass().getResource("FXMLDocument.fxml"));

        Scene scene = new Scene(root);

        stage.setScene(scene);
        stage.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args)
    {
        launch(args);
    }

}

控制器

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.RowConstraints?>
<?import javafx.scene.layout.StackPane?>
<?import javafx.scene.layout.VBox?>

<AnchorPane id="AnchorPane" prefHeight="200" prefWidth="320" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.111" fx:controller="watereddowncalculator.FXMLDocumentController">
    <children>
      <VBox prefHeight="200.0" prefWidth="100.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
         <children>
            <TextField fx:id="tfDisplay">
               <VBox.margin>
                  <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
               </VBox.margin>
            </TextField>
            <StackPane prefHeight="150.0" prefWidth="200.0">
               <children>
                  <GridPane maxHeight="100.0" maxWidth="100.0" prefHeight="50.0" prefWidth="50.0">
                    <columnConstraints>
                      <ColumnConstraints hgrow="SOMETIMES" minWidth="50.0" prefWidth="50.0" />
                      <ColumnConstraints hgrow="SOMETIMES" minWidth="50.0" prefWidth="50.0" />
                    </columnConstraints>
                    <rowConstraints>
                      <RowConstraints vgrow="SOMETIMES" />
                      <RowConstraints vgrow="SOMETIMES" />
                      <RowConstraints vgrow="SOMETIMES" />
                    </rowConstraints>
                     <children>
                        <Button maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" onAction="#handleButtonAction" text="1">
                           <GridPane.margin>
                              <Insets bottom="2.0" left="2.0" right="2.0" top="2.0" />
                           </GridPane.margin>
                        </Button>
                        <Button maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" onAction="#handleButtonAction" text="2" GridPane.columnIndex="1">
                           <GridPane.margin>
                              <Insets bottom="2.0" left="2.0" right="2.0" top="2.0" />
                           </GridPane.margin>
                        </Button>
                        <Button maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" onAction="#handleButtonAction" text="3" GridPane.rowIndex="1">
                           <GridPane.margin>
                              <Insets bottom="2.0" left="2.0" right="2.0" top="2.0" />
                           </GridPane.margin>
                        </Button>
                        <Button maxHeight="1.7976931348623157E308" maxWidth="1.7976931348623157E308" mnemonicParsing="false" onAction="#handleButtonAction" text="+" GridPane.columnIndex="1" GridPane.rowIndex="1">
                           <GridPane.margin>
                              <Insets bottom="2.0" left="2.0" right="2.0" top="2.0" />
                           </GridPane.margin>
                        </Button>
                        <Button maxWidth="1.7976931348623157E308" mnemonicParsing="false" onAction="#handleButtonAction" text="=" GridPane.columnSpan="2" GridPane.rowIndex="2" />
                     </children>
                  </GridPane>
               </children>
            </StackPane>
         </children>
      </VBox>

    </children>
</AnchorPane>

Pure Code Version

import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;

/**
 *
 * @author blj0011
 */
public class FXMLDocumentController implements Initializable
{
    @FXML TextField tfDisplay;//TextField create using FXML

    //Method use the handle the different buttons' action.
    @FXML
    private void handleButtonAction(ActionEvent event)
    {
        Button tempButton = ((Button)event.getSource());//Get the Button that is being pressed

        String currentButtonPress = tempButton.getText();//Get the text of the button that is being pressed

        //Depending on the Button text do some action
        switch(currentButtonPress)
        {
            case "=":
                //do some calculation
                break;
            case "+":
                tfDisplay.appendText(currentButtonPress);
                break;
            default:
                tfDisplay.appendText(currentButtonPress);                
        }

    }

    @Override
    public void initialize(URL url, ResourceBundle rb)
    {
        // TODO
    }    

}

您可能希望以不同的方式处理import javafx.application.*; import javafx.event.*; import javafx.geometry.*; import javafx.scene.*; import javafx.scene.control.*; import javafx.scene.layout.*; import javafx.stage.*; /** * * @author Sedrick */ public class JavaFXApplication60 extends Application { @Override public void start(Stage primaryStage) { AnchorPane root = new AnchorPane(); VBox vBox = new VBox(); AnchorPane.setBottomAnchor(vBox, 0.0); AnchorPane.setTopAnchor(vBox, 0.0); AnchorPane.setRightAnchor(vBox, 0.0); AnchorPane.setLeftAnchor(vBox, 0.0); root.getChildren().add(vBox); TextField display = new TextField(); display.setEditable(false);//Don't allow the TextField to be editable. vBox.getChildren().add(display); VBox.setMargin(display, new Insets(10, 10, 10, 10)); StackPane stackPane = new StackPane(); stackPane.setPrefSize(200, 150); vBox.getChildren().add(stackPane); GridPane gridPane = new GridPane(); //gridPane.gridLinesVisibleProperty().set(true); gridPane.setMinSize(50, 50); gridPane.setPrefSize(50, 50); gridPane.setMaxSize(100, 100); gridPane.setVgap(2); gridPane.setHgap(2); RowConstraints rowConstraints = new RowConstraints(); rowConstraints.setVgrow(Priority.SOMETIMES); gridPane.getRowConstraints().addAll(rowConstraints, rowConstraints, rowConstraints); ColumnConstraints columnConstraints = new ColumnConstraints(); columnConstraints.setHgrow(Priority.SOMETIMES); columnConstraints.setMinWidth(50); columnConstraints.setPrefWidth(50); gridPane.getColumnConstraints().addAll(columnConstraints, columnConstraints); stackPane.getChildren().add(gridPane); //Create Buttons Button btn1 = new Button("1"); Button btn2 = new Button("2"); Button btn3 = new Button("3"); Button btnPlus = new Button("+"); Button btnEqual = new Button("="); btn1.setMaxSize(Double.MAX_VALUE, Double.MAX_VALUE); btn2.setMaxSize(Double.MAX_VALUE, Double.MAX_VALUE); btn3.setMaxSize(Double.MAX_VALUE, Double.MAX_VALUE); btnPlus.setMaxSize(Double.MAX_VALUE, Double.MAX_VALUE); btnEqual.setMaxSize(Double.MAX_VALUE, Double.MAX_VALUE); //Create event handler EventHandler handle = new EventHandler() { @Override public void handle(Event event) { Button tempButton = ((Button) event.getSource());//Get the Button that is being pressed String currentButtonPress = tempButton.getText();//Get the text of the button that is being pressed //Depending on the Button text do some action switch (currentButtonPress) { case "=": display.setText("results!"); break; case "+": display.appendText(currentButtonPress); break; default: display.appendText(currentButtonPress); } } }; //Set buttons' handlers; btn1.setOnAction(handle); btn2.setOnAction(handle); btn3.setOnAction(handle); btnPlus.setOnAction(handle); btnEqual.setOnAction(handle); gridPane.add(btn1, 0, 0, 1, 1); gridPane.add(btn2, 1, 0, 1, 1); gridPane.add(btn3, 0, 1, 1, 1); gridPane.add(btnPlus, 1, 1, 1, 1); gridPane.add(btnEqual, 0, 2, 2, 1); Scene scene = new Scene(root, 300, 220); primaryStage.setTitle("Hello World!"); primaryStage.setScene(scene); primaryStage.show(); } /** * @param args the command line arguments */ public static void main(String[] args) { launch(args); } }操作。

Answer 3

@Arturo，我记得你的申请。

对于＃1子问题：没有想法，不清楚最终目标。

对于＃2子问题：您已在结果字段中显示了值。

对于＃3子问题：要附加新的按下值，您可以执行下一个：

tres.pressedProperty().addListener((o, old, newValue) -> {
    if (newValue) {
        if ("0".equals(Result.getText()) {
            Result.setText("3");
        } else {
            Result.appendText("3");
        }
    }
});

结果你会得到：＆＃34; 11113＆＃34;

修改：从第一个零添加保护。为避免每个按钮上的重复，您可以将if / else提取到私有方法中并调用updateResult（＆＃34; 3＆＃34;）;

如何从textField（JavaFX）获取文本

3 个答案: