計算器——JAVA的AWT與swing組件

實現效果

友情提示：建議您把代碼複製到自己的編譯器裏去研究算法，博文看着實屬有些累，前提您需要一定的 java 基礎哦~

網格袋類

package jsj;
import java.awt.Component;
import java.awt.Container;
import java.awt.GridBagConstraints;
import java.awt.Insets;

public class LayoutUtil {
	//參數含義介紹     1. Container container 容器對象
	//             2. int fill 填充方式
	//             3. int anchor  停靠位置（對齊方式）
	//             4. int weightx 水平權值    與填充方式有內在關係
	//             5. int weighty 垂直權值    與填充方式有內在關係
	//             6. int x    水平起點
	//             7. int y    垂直起點
	//             8. int width  水平寬度(水平佔鋸的單元格數)
	//             9. int height  垂直寬度(垂直佔鋸的單元格數)
	//            10. Component comp 組件對象
    public static void add(Container container,int fill,
    		int anchor,int weightx,int weighty,
    		int x,int y,int width,int height,Component comp){
    	GridBagConstraints constraints=new GridBagConstraints();
    	constraints.fill=fill;
    	constraints.anchor=anchor;
    	constraints.weightx=weightx;
    	constraints.weighty=weighty;
    	constraints.gridx=x;
    	constraints.gridy=y;
    	constraints.gridwidth=width;
    	constraints.gridheight=height;
    	container.add(comp,constraints);
    }                     // 參數含義同上，只新增一個 外邊距參數
    public static void add(Container container,int fill,
    		int anchor,int weightx,int weighty,      // Insets insets 外邊距填充方式
    		int x,int y,int width,int height,Component comp,Insets insets){
    	GridBagConstraints constraints=new GridBagConstraints();
    	constraints.insets=insets;
    	constraints.fill=fill;
    	constraints.anchor=anchor;
    	constraints.weightx=weightx;
    	constraints.weighty=weighty;
    	constraints.gridx=x;
    	constraints.gridy=y;
    	constraints.gridwidth=width;
    	constraints.gridheight=height;
    	container.add(comp,constraints);
    }

}

計算器的實現

package jsj;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.TitledBorder;
import jsj.LayoutUtil;

public class Calculator extends JFrame {
	static int count1=0;//計數第一位數點擊按鈕次數,用來判斷小數位數，除以多少個10
	static int count2=0;//計數第二位數點擊按鈕次數,用來判斷小數位數，除以多少個10
	static int k=0;			//判斷是否點過運算符+-*/
	static float a=0;		//存第一位計算數
	static float b=0;		//存第二位計算數
	static float c=0;		//存運算結果
	static int pointt=0;//判斷是否點過小數點 .
	static int jiat=0;//判斷是否點過加號+
	static int jiant=0;//判斷是否點過減號-
	static int chengt=0;//判斷是否點過乘號*
	static int chut=0;//判斷是否點過除號/
	
	/*各個按鈕*/
	JButton jia=new JButton("+");
	JButton jian=new JButton("-");
	JButton cheng=new JButton("*");
	JButton chu=new JButton("/");
	JButton one=new JButton("1");
	JButton two=new JButton("2");
	JButton three=new JButton("3");
	JButton four=new JButton("4");
	JButton five=new JButton("5");
	JButton six=new JButton("6");
	JButton seven=new JButton("7");
	JButton eight=new JButton("8");
	JButton nine=new JButton("9");
	JButton zero=new JButton("0");
	JButton clean=new JButton("CE");
	JButton point=new JButton(".");
	JButton result=new JButton("=");
	
	/*顯示文字與運算結果面板*/
	JPanel showJPanel=new JPanel();
	/*顯示最上面文字標籤*/
	JLabel showresult2=new JLabel("鳳兮鳳兮歸故鄉，遨遊四海求其凰");
	/*顯示運算結果標籤*/
	JLabel showresult=new JLabel("0");
	
	/*存放各個按鈕面板*/
	JPanel show=new JPanel();
	
	public static void main(String[] args) {
		Calculator calculator=new Calculator();
		calculator.setVisible(true);
	}
	public Calculator(){
		super();
		setTitle("計算器");//設置框體標題
		setBounds(300, 300, 300, 250);//設置框體默認大小
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setResizable(false);
		
		showresult2.setBorder(new TitledBorder(null, "", TitledBorder.DEFAULT_JUSTIFICATION, TitledBorder.DEFAULT_POSITION, null,
				null));//給最上方文字加邊框
		showresult.setBorder(new TitledBorder(null, "", TitledBorder.DEFAULT_JUSTIFICATION, TitledBorder.DEFAULT_POSITION, null,
				null));//給運算結果加邊框
		showresult2.setForeground(new Color(255, 0, 0));//給最上方文字設置紅色
		showresult2.setFont(new Font("", Font.BOLD, 15));//給最上方文字設置大小
		
		showJPanel.setLayout(new GridBagLayout());//對顯示文字與運算結果面板設置網格袋佈局
		LayoutUtil.add(showJPanel,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,0,0,1,1,showresult2);
		LayoutUtil.add(showJPanel,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,0,1,1,1,showresult);
		getContentPane().add(showJPanel,BorderLayout.NORTH);//將面板放在內容窗格北方
		
		show.setLayout(new GridBagLayout());//對存放各個按鈕面板設置網格袋佈局
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,3,0,1,1,clean);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,0,1,1,1,seven);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,1,1,1,1,eight);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,2,1,1,1,nine);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,3,1,1,1,jia);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,0,2,1,1,four);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,1,2,1,1,five);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,2,2,1,1,six);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,3,2,1,1,jian);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,0,3,1,1,one);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,1,3,1,1,two);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,2,3,1,1,three);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,3,3,1,1,cheng);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,0,4,1,1,point);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,1,4,1,1,zero);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,2,4,1,1,result);
		LayoutUtil.add(show,GridBagConstraints.HORIZONTAL,GridBagConstraints.CENTER,1,0,3,4,1,1,chu);
		getContentPane().add(show,BorderLayout.SOUTH);//將面板放在內容窗格南方
		
		point.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				pointt=1;//如果點擊小數點，設置pointt=1計數
				/*令計數開始計數小數位個數*/
				count1=0;
				count2=0;
			}
		});
		clean.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
					//清空數值
					a=0;
					c=0;
					b=0;
					pointt=0;
					count1=0;count2=0;
					/*將float類型轉化成String類型，因爲setText()放String類型參數*/
					String d=Float.toString(c);
					showresult.setText(d);
			}
		});
		
	/*請翻到nine，這裏以nine爲例解釋算法 ，zero,one,two,three,four,five,six,seven,eight原理均同nine*/	
		zero.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(k==0) {
					a=a*10+0;
					count1++;
					if(pointt==1) {
						a=(float) (a/Math.pow(10, count1));
						String d=Float.toString(a);
						showresult.setText(d);
						a=(float) (a*Math.pow(10, count1));
					}
					else{
					String d=Float.toString(a);
					showresult.setText(d);
					}
				}
				if(k==1){
					b=b*10+0;
					count2++;
					if(pointt==1) {
						b=(float) (b/Math.pow(10, count2));
						pointt=0;
						String d=Float.toString(b);
						showresult.setText(d);
						b=(float) (b*Math.pow(10, count2));
					}
					else{
					String d=Float.toString(b);
					showresult.setText(d);
					}
				}
			}
		});
		one.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(k==0) {
					a=a*10+1;
					count1++;
					if(pointt==1) {
						a=(float) (a/Math.pow(10, count1));
						String d=Float.toString(a);
						showresult.setText(d);
						a=(float) (a*Math.pow(10, count1));
					}
					else{
					String d=Float.toString(a);
					showresult.setText(d);
					}
				}
				if(k==1){
					b=b*10+1;
					count2++;
					if(pointt==1) {
						b=(float) (b/Math.pow(10, count2));
						pointt=0;
						String d=Float.toString(b);
						showresult.setText(d);
						b=(float) (b*Math.pow(10, count2));
					}
					else{
					String d=Float.toString(b);
					showresult.setText(d);
					}
				}
			}
		});
		two.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(k==0) {
					a=a*10+2;
					count1++;
					if(pointt==1) {
						a=(float) (a/Math.pow(10, count1));
						String d=Float.toString(a);
						showresult.setText(d);
						a=(float) (a*Math.pow(10, count1));
					}
					else{
					String d=Float.toString(a);
					showresult.setText(d);
					}
				}
				if(k==1){
					b=b*10+2;
					count2++;
					if(pointt==1) {
						b=(float) (b/Math.pow(10, count2));
						pointt=0;
						String d=Float.toString(b);
						showresult.setText(d);
						b=(float) (b*Math.pow(10, count2));
					}
					else{
					String d=Float.toString(b);
					showresult.setText(d);
					}
				}
			}
		});
		three.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(k==0) {
					a=a*10+3;
					count1++;
					if(pointt==1) {
						a=(float) (a/Math.pow(10, count1));
						String d=Float.toString(a);
						showresult.setText(d);
						a=(float) (a*Math.pow(10, count1));
					}
					else{
					String d=Float.toString(a);
					showresult.setText(d);
					}
				}
				if(k==1){
					b=b*10+3;
					count2++;
					if(pointt==1) {
						b=(float) (b/Math.pow(10, count2));
						pointt=0;
						String d=Float.toString(b);
						showresult.setText(d);
						b=(float) (b*Math.pow(10, count2));
					}
					else{
					String d=Float.toString(b);
					showresult.setText(d);
					}
				}
			}
		});
		four.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(k==0) {
					a=a*10+4;
					count1++;
					if(pointt==1) {
						a=(float) (a/Math.pow(10, count1));
						String d=Float.toString(a);
						showresult.setText(d);
						a=(float) (a*Math.pow(10, count1));
					}
					else{
					String d=Float.toString(a);
					showresult.setText(d);
					}
				}
				if(k==1){
					b=b*10+4;
					count2++;
					if(pointt==1) {
						b=(float) (b/Math.pow(10, count2));
						pointt=0;
						String d=Float.toString(b);
						showresult.setText(d);
						b=(float) (b*Math.pow(10, count2));
					}
					else{
					String d=Float.toString(b);
					showresult.setText(d);
					}
				}
			}
		});
		five.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(k==0) {
					a=a*10+5;
					count1++;
					if(pointt==1) {
						a=(float) (a/Math.pow(10, count1));
						String d=Float.toString(a);
						showresult.setText(d);
						a=(float) (a*Math.pow(10, count1));
					}
					else{
					String d=Float.toString(a);
					showresult.setText(d);
					}
				}
				if(k==1){
					b=b*10+5;
					count2++;
					if(pointt==1) {
						b=(float) (b/Math.pow(10, count2));
						pointt=0;
						String d=Float.toString(b);
						showresult.setText(d);
						b=(float) (b*Math.pow(10, count2));
					}
					else{
					String d=Float.toString(b);
					showresult.setText(d);
					}
				}
			}
		});
		six.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(k==0) {
					a=a*10+6;
					count1++;
					if(pointt==1) {
						a=(float) (a/Math.pow(10, count1));
						String d=Float.toString(a);
						showresult.setText(d);
						a=(float) (a*Math.pow(10, count1));
					}
					else{
					String d=Float.toString(a);
					showresult.setText(d);
					}
				}
				if(k==1){
					b=b*10+6;
					count2++;
					if(pointt==1) {
						b=(float) (b/Math.pow(10, count2));
						pointt=0;
						String d=Float.toString(b);
						showresult.setText(d);
						b=(float) (b*Math.pow(10, count2));
					}
					else{
					String d=Float.toString(b);
					showresult.setText(d);
					}
				}
			}
		});
		seven.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(k==0) {
					a=a*10+7;
					count1++;
					if(pointt==1) {
						a=(float) (a/Math.pow(10, count1));
						String d=Float.toString(a);
						showresult.setText(d);
						a=(float) (a*Math.pow(10, count1));
					}
					else{
					String d=Float.toString(a);
					showresult.setText(d);
					}
				}
				if(k==1){
					b=b*10+7;
					count2++;
					if(pointt==1) {
						b=(float) (b/Math.pow(10, count2));
						pointt=0;
						String d=Float.toString(b);
						showresult.setText(d);
						b=(float) (b*Math.pow(10, count2));
					}
					else{
					String d=Float.toString(b);
					showresult.setText(d);
					}
				}
			}
		});
	eight.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(k==0) {
					a=a*10+8;
					count1++;
					if(pointt==1) {
						a=(float) (a/Math.pow(10, count1));
						String d=Float.toString(a);
						showresult.setText(d);
						a=(float) (a*Math.pow(10, count1));
					}
					else{
					String d=Float.toString(a);
					showresult.setText(d);
					}
				}
				if(k==1){
					b=b*10+8;
					count2++;
					if(pointt==1) {
						b=(float) (b/Math.pow(10, count2));
						pointt=0;
						String d=Float.toString(b);
						showresult.setText(d);
						b=(float) (b*Math.pow(10, count2));
					}
					else{
					String d=Float.toString(b);
					showresult.setText(d);
					}
				}
			}
		});
	/*算法解釋：*/
	nine.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(k==0) {//輸入第一位數
					a=a*10+9;//輸入爲999...一個個輸入，拼湊規則（初始化a=0） 9=0*10+9  ->  99=9*10+9->999=99*10+9...
					count1++;//count1加一
					if(pointt==1) {//如果點擊小數點後（point按鍵部分令count1=0，count1從頭開始即計數小數位數字個數）
						a=(float) (a/Math.pow(10, count1));//Math.pow(10,count1)即10的count1次方，此次獲得a的小數形式如9.99僅爲了顯示
						String d=Float.toString(a);
						showresult.setText(d);//顯示a的小數形式
						a=(float) (a*Math.pow(10, count1));//顯示後變回a的整數形式999(爲了按鍵下一個小數位此時，count1隨按鍵次數增加而增加一，因此小數點會根據按鍵次數“往前移”)
					}
					else{//爲涉及小數點的整數輸出
					String d=Float.toString(a);
					showresult.setText(d);
					}
				}
				if(k==1){//輸入第二位數，下面原理同第一個數的輸入
					b=b*10+9;
					count2++;
					if(pointt==1) {
						b=(float) (b/Math.pow(10, count2));
						pointt=0;
						String d=Float.toString(b);
						showresult.setText(d);
						b=(float) (b*Math.pow(10, count2));
					}
					else{
					String d=Float.toString(b);
					showresult.setText(d);
					}
				}
			}
		});
		jia.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				/*當點擊加號後，k=1即下面點擊數字輸入的是b的值，jiat用來在=輸出結果時計算方式判斷*/
				 k=1;
				jiat=1;
		if(pointt==1) {a=(float) (a/Math.pow(10, count1));pointt=0;}//涉及小數點，前面是爲了顯示，這次第一個數不在輸入，則這個a的值用於計算
			}
		});
		/*減乘除號原理均同加號原理*/
		jian.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				 k=1;
				jiant=1;
				if(pointt==1) {a=(float) (a/Math.pow(10, count1));pointt=0;}
			}
		});
		cheng.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				 k=1;
				chengt=1;
				if(pointt==1) {a=(float) (a/Math.pow(10, count1));pointt=0;}
			}
		});
		chu.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				 k=1;
				chut=1;
				if(pointt==1) {a=(float) (a/Math.pow(10, count1));pointt=0;}
			}
		});
		
		result.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent event) {
				if(pointt==1) {//涉及小數點，前面是爲了顯示，這次第二個數不在輸入，則這個b的值用於計算
				pointt=0;
				b=(float) (b/Math.pow(10, count2));
				}
			if(k==1) {//點擊過運算符
				 if(jiat==1) {c=a+b;a=c;jiat=0;}//最後把c的值給a，爲了銜接計算，即如2+3+4...
				 else if(jiant==1) {c=a-b;a=c;jiant=0;}
				 else if(chengt==1) {c=a*b;a=c;chengt=0;}
				 else if(chut==1) {c=a/b;chut=0;a=c;}
					String d=Float.toString(c);
					showresult.setText(d);
			}
			 else {//未點過運算符，輸入a的值後直接點=號，則直接輸出a的值
						String d=Float.toString(a);
						showresult.setText(d);
				 }
			/*計算完後重新初始化（a沒必要初始化,因爲要銜接計算）*/
			count1=0;count2=0;
           k=0;b=0;chengt=0;jiat=0;
          // 思考：如果不銜接計算了，a的值又要爲0重新開始輸入，那麼a=0放在什麼位置，否則會把上一次的c結果值如22給a進行下一次a的輸入，我們再輸個3，會變成223，不符合實際情況，我們應該只需要3
			
			}
		});
	}
}