03 一个计算器，switch语句

最新推荐文章于 2024-09-25 20:49:05 发布

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最新推荐文章于 2024-09-25 20:49:05 发布

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分类专栏： java语言文章标签： netbeans string 存储 byte

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本教程详细介绍了如何在NetBeans中创建一个包含1个文本框和18个操作按钮的JFrame实例。通过编写特定的Java代码，实现了数字输入、运算符选择及计算结果显示的功能。

在NetBeans中创建一个项目，不要主类，新建一个JFrame，添加一个jTextFiled，18个jButton，如下图：

添加下面这些代码：

double temp;
double result;//存储结果
String s = "";//存储显示在屏幕上的值
String s1 = "";//存储参与计算的值
byte flag = 0;/*flag=0表示没有选择运算符，1表示加号，2表示减号，
3表示乘号，4表示除号，5表示取余*/

private void jButton1MouseReleased(java.awt.event.MouseEvent evt) {
flag = 1;
s1 = jTextField1.getText();
try {
temp = Double.parseDouble(s1);
result = temp;
} catch (NumberFormatException e) {
jTextField1.setText("还没有输入数字");
}
jTextField1.setText("+");
s = "";
}

private void jButton2MouseReleased(java.awt.event.MouseEvent evt) {
flag = 2;
s1 = jTextField1.getText();
try {
temp = Double.parseDouble(s1);
result = temp;
} catch (NumberFormatException e) {
jTextField1.setText("还没有输入数字");
}
jTextField1.setText("-");
s = "";
}

private void jButton3MouseReleased(java.awt.event.MouseEvent evt) {
flag = 3;
s1 = jTextField1.getText();
try {
temp = Double.parseDouble(s1);
result = temp;
} catch (NumberFormatException e) {
jTextField1.setText("还没有输入数字");
}
jTextField1.setText("*");
s = "";
}

private void jButton4MouseReleased(java.awt.event.MouseEvent evt) {
flag = 4;
s1 = jTextField1.getText();
try {
temp = Double.parseDouble(s1);
result = temp;
} catch (NumberFormatException e) {
jTextField1.setText("还没有输入数字");
}
jTextField1.setText("/");
s = "";
}

private void jButton5MouseReleased(java.awt.event.MouseEvent evt) {
flag = 5;
s1 = jTextField1.getText();
try {
temp = Double.parseDouble(s1);
result = temp;
} catch (NumberFormatException e) {
jTextField1.setText("还没有输入数字");
}
jTextField1.setText("%");
s = "";
}

private void jButton7MouseReleased(java.awt.event.MouseEvent evt) {
s = s + 1;
jTextField1.setText(s);
}

private void jButton8MouseReleased(java.awt.event.MouseEvent evt) {
s = s + 2;
jTextField1.setText(s);
}

private void jButton9MouseReleased(java.awt.event.MouseEvent evt) {
s = s + 3;
jTextField1.setText(s);
}

private void jButton11MouseReleased(java.awt.event.MouseEvent evt) {
s = s + 4;
jTextField1.setText(s);
}

private void jButton10MouseReleased(java.awt.event.MouseEvent evt) {
s = s + 5;
jTextField1.setText(s);
}

private void jButton12MouseReleased(java.awt.event.MouseEvent evt) {
s = s + 6;
jTextField1.setText(s);
}

private void jButton13MouseReleased(java.awt.event.MouseEvent evt) {
s = s + 7;
jTextField1.setText(s);
}

private void jButton15MouseReleased(java.awt.event.MouseEvent evt) {
s = s + 8;
jTextField1.setText(s);
}

private void jButton14MouseReleased(java.awt.event.MouseEvent evt) {
s = s + 9;
jTextField1.setText(s);
}

private void jButton17MouseReleased(java.awt.event.MouseEvent evt) {
s = s + '.';
jTextField1.setText(s);
}

private void jButton16MouseReleased(java.awt.event.MouseEvent evt) {
s = s + 0;
jTextField1.setText(s);
}

private void jButton18MouseReleased(java.awt.event.MouseEvent evt) {
s1 = jTextField1.getText().trim();
temp = Double.parseDouble(s1);
switch (flag) {
case 1:
result = result + temp;
break;
case 2:
result = result - temp;
break;
case 3:
result = result * temp;
break;
case 4:
result = result / temp;
break;
case 5:
result = result % temp;
break;
default:
jTextField1.setText("出现错误!");
}
jTextField1.setText(String.valueOf(result));
s = "";
}

private void jButton6MouseReleased(java.awt.event.MouseEvent evt) {
result = 0;
s = "";
s1 = "";
flag = 0;
jTextField1.setText("");
}