JavaFx实例2：制作简单的计算器【Create a Calculator GUI】

        下面将介绍JavaFx的第二个实例，制作简单的计算器（真的只是一个简简单单的计算机，有很多功能还没有实现，有兴趣的同学可以自己完善，之后有空的话也会详细讲一下，程序有bug大家可以多多提出哈）

package com.example.chatclient;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.effect.DropShadow;
import javafx.scene.input.DragEvent;
import javafx.scene.input.MouseButton;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Border;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.scene.shape.Circle;
import javafx.scene.text.Font;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

public class Calculator extends Application {
    double result = 0;//结果
    String Laststr = "0";//上一字符,用于保存输入的数字
    TextField textField1;//输出窗口
    char LastOperator = ' ';//上一个运算符
    String show= new String();
    @Override
    public void start(Stage primaryStage){
        //1>设置上方栏
        TextField textField = new TextField("Calculator");
        textField.setFont(new Font(30));//设置字体大小为30
        textField.setAlignment(Pos.CENTER);//将文本居中
        textField.setEditable(false);//使文本不可编辑
        textField.setStyle("-fx-background-color: #B65C61;-fx-text-fill: white");//设置字体以及填充色
        textField.setPrefWidth(300);//设置文本框宽度
        textField.setPrefHeight(85);//设置文本框高度
        //设置按钮及其属性
        Button f1 = new Button("-");
        Button f2 = new Button("·");
        Button f3 = new Button("□");
        f1.setPrefWidth(85);//设置按钮大小:宽
        f1.setPrefHeight(85);//设置按钮大小:高
        f2.setPrefWidth(85);
        f2.setPrefHeight(85);
        f3.setPrefWidth(85);
        f3.setPrefHeight(85);
        f1.setStyle("-fx-background-color: #B65C61;-fx-font-size: 30");//设置按钮填充色以及大小
        f2.setStyle("-fx-background-color: #B65C61;-fx-font-size: 30");
        f3.setStyle("-fx-background-color: #B65C61;-fx-font-size: 30");
        //设计鼠标置于按钮上方时按钮效果
        f1.setOnMouseEntered(o->((Button)o.getSource()).setStyle("-fx-border-width: 1;-fx-border-color: blue;-fx-font-size: 30"));
        f2.setOnMouseEntered(o->((Button)o.getSource()).setStyle("-fx-border-width: 1;-fx-border-color: blue;-fx-font-size: 30"));
        f3.setOnMouseEntered(o->((Button)o.getSource()).setStyle("-fx-border-width: 1;-fx-border-color: blue;-fx-font-size: 30"));
        f1.setOnMouseExited(o->((Button)o.getSource()).setStyle("-fx-background-color: #B65C61;-fx-font-size: 30"));
        f2.setOnMouseExited(o->((Button)o.getSource()).setStyle("-fx-background-color: #B65C61;-fx-font-size: 30"));
        f3.setOnMouseExited(o->((Button)o.getSource()).setStyle("-fx-background-color: #B65C61;-fx-font-size: 30"));
        //设计单击时按钮效果
        f1.setOnAction(o->{
            primaryStage.setIconified(true);//最小化窗口
        });
        f2.setOnAction(o->{//清零显示屏
            result = 0;
            Laststr = "0";
            LastOperator = ' ';
            show = new String();
            textField1.setText("0.0");
        });
        f3.setOnAction(o->{
            primaryStage.close();//关闭窗口
        });
        //置于HBox中
        HBox hBox = new HBox(2);//设置元素间隔为2
        hBox.setPadding(new Insets(2,2,2,2));
        hBox.getChildren().addAll(f1,textField,f2,f3);
        //2>设置显示器
        textField1 = new TextField("0.0");//定义显示器并设置初始值
        textField1.setAlignment(Pos.BASELINE_RIGHT);//设置显示内容右对齐
        textField1.setStyle("-fx-background-color: #D9C1B2;-fx-border-width: 0;-fx-font-size: 20");
        //3>设置键盘
        //设置按钮
        String string = "789+456-123*0.=/";
        Button[] buttonarray = new Button[16];
        for(int i=0;i<16;i++){
            buttonarray[i]= new Buttons(string.charAt(i)+"");
            buttonarray[i].setOnMouseEntered(o->{
                ((Button)o.getSource()).setStyle("-fx-background-color: #B65C61");
            });
            buttonarray[i].setOnMouseExited(o->{
                ((Button)o.getSource()).setStyle("-fx-border-width :0");
            });
            buttonarray[i].setOnAction(new CalculatorHandler());//为按钮添加触发事件
        }
        //填充按钮到单元格
        GridPane gridPane = new GridPane();
        gridPane.setVgap(3);//设置单元格之间的垂直间隙
        gridPane.setHgap(2);//设置单元格之间的水平间隙
        gridPane.setPadding(new Insets(0,2,2,2));//设置girdPane距离上边,右边,下边,左边的距离
        int count=0;
        for(int i=0;i<4;i++)
            for(int j=0;j<4;j++)
                gridPane.add(buttonarray[count++],j,i);
        //将各元素放在BorderPane中
        BorderPane borderPane = new BorderPane();
        borderPane.setTop(hBox);
        borderPane.setStyle("-fx-background-color: #D9C1B2;-fx-border-color: #B65C61;-fx-border-width: 8");
        borderPane.setCenter(textField1);
        borderPane.setBottom(gridPane);
        DragWindowHandler handler = new DragWindowHandler(primaryStage);//创建DragWindowHandler
        borderPane.setOnMouseDragged(handler::handle2);//设置鼠标拖动事件,鼠标放开时
        borderPane.setOnMouseReleased(handler::handle1);//设置鼠标拖动事件,鼠标拖动时
        //置入舞台
        Scene scene = new Scene(borderPane);
        primaryStage.setTitle("Calculator");
        primaryStage.initStyle(StageStyle.UNDECORATED);//设置舞台属性,隐藏舞台自带的上边栏
        primaryStage.setScene(scene);
        primaryStage.setWidth(500);
        primaryStage.setHeight(600);
        primaryStage.show();
    }
    public static  void main(String[] args){launch(args);}
    class Buttons extends Button{
        public Buttons(String args){
            super(args);//调用父类的构造方法
            setPrefWidth(130);//设置每个单元格的宽度
            setPrefHeight(90);//设置每个单元格的长度
            setFont(new Font(30));//设置字体大小
        }
    }
    public class DragWindowHandler{//用于设置拖拽事件
        private Stage primaryStage;
        private double oldStageX;
        private double oldStageY;
        private double oldScreenX;
        private double oldScreenY;
        private boolean move = true;
        public  DragWindowHandler(Stage primaryStage){
            this.primaryStage=primaryStage;
        }
        public void handle2(MouseEvent e){
            if(move){//获取旧坐标
                this.oldStageX = this.primaryStage.getX();
                this.oldStageY = this.primaryStage.getY();
                this.oldScreenX = e.getScreenX();
                this.oldScreenY = e.getScreenY();
                move=false;
            }
            else {
                this.primaryStage.setX(e.getScreenX() - this.oldScreenX + this.oldStageX);//设置新X轴
                this.primaryStage.setY(e.getScreenY() - this.oldScreenY + this.oldStageY);//设置新Y轴
            }
        }
        public void handle1(MouseEvent e){move = true;}
    }
    class CalculatorHandler implements EventHandler{//设置按钮点击事件
        @Override
        public void handle(ActionEvent event){
            String currentButton = ((Button)event.getSource()).getText();//获取目前点击的按钮
            show+=currentButton;//展示框中展示的字符串
            textField1.setText(show);
            switch(currentButton){
                case "0": case"1": case"2": case"3": case"4": case"5": case"6": case"7": case"8": case"9": case".":
                    if(Laststr.equals("0"))
                        Laststr = currentButton;//如果上一个输入的是0的话,刷新Laststr
                    else Laststr += currentButton;break;//小数有奇效
                default:
                    compute();//计算
                    LastOperator=currentButton.charAt(0);
                    if(LastOperator=='=')compute();//等于时再计算一遍,因为即时性
            }
        }
        private void compute(){//用于处理输入的数字
            double Number = Double.parseDouble(Laststr);
            System.out.println(Laststr);
            Laststr = "0";
            int o=0;
            switch(LastOperator){
                case ' ': result = Number;break;
                case '+': result += Number;break;
                case '-': result -= Number;break;
                case '*': result *= Number;break;
                case '/': result /= Number;break;
                case '=':
                    textField1.setText(result + " ");
                    result=0;
                    LastOperator=' ';
                    Laststr = "0";
                    show= new String();break;
                default:break;
            }
        }
    }
}