c#做的计算器怎么避免小数点以及计算符号被连续输入！！
代码如下
using System;
using System.IO;
using System.Windows.Forms;
//using static System.Windows.Forms.VisualStyles.VisualStyleElement;
namespace 计算器demo2
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private double currentResult; //临时结果
private string lastOperator;//上一次的操作
private void btn1_Click(object sender, EventArgs e)
{
textBox.Text += 1;
}
private void btn0_Click(object sender, EventArgs e)
{
textBox.Text += 0;
}
private void btn2_Click(object sender, EventArgs e)
{
textBox.Text += 2;
}
private void btn3_Click(object sender, EventArgs e)
{
textBox.Text += 3;
}
private void btn4_Click(object sender, EventArgs e)
{
textBox.Text += 4;
}
private void btn5_Click(object sender, EventArgs e)
{
textBox.Text += 5;
}
private void btn6_Click(object sender, EventArgs e)
{
textBox.Text += 6;
}
private void btn7_Click(object sender, EventArgs e)
{
textBox.Text += 7;
}
private void btn8_Click(object sender, EventArgs e)
{
textBox.Text += 8;
}
private void btn9_Click(object sender, EventArgs e)
{
textBox.Text += 9;
}
private void btn_Clear_Click(object sender, EventArgs e)
{
textBox.Text = "";//修改显示为kong，实现清楚
txtResult.Text = "";
}
private void btn_Add_Click(object sender, EventArgs e)
{
Button btn = (Button)sender;
textBox.Text = textBox.Text + " " + btn.Text + " ";
{
btnAdd.Enabled = false;
}
}
private void btn_Compute_Click(object sender, EventArgs e)
{
Single r; //r用于保存结果值
string t = textBox.Text; //t用于保存文本框中的算术表达式
int space = t.IndexOf(" "); //用于搜索空格位置
string s1 = t.Substring(0, space); //s1用于保存第一个运算数
char op = Convert.ToChar(t.Substring(space + 1, 1)); //op用于保存运算符
string s2 = t.Substring(space + 3); //s2用于保存第二个运算数
Single arg1 = Convert.ToSingle(s1);
Single arg2 = Convert.ToSingle(s2);//Convert.ToSingle方法将字符串或者其他可转换为数字的对象变量转换为float类型
switch (op)
{
case '+':
r = arg1 + arg2;
break;
case '-':
r = arg1 - arg2;
break;
case '*':
r = arg1 * arg2;
break;
case '/':
if (arg2 == 0)
{
MessageBox.Show("0不能作为除数!");
return;
}
else
{
r = arg1 / arg2;
break;
}
default:
throw new ApplicationException();
}
txtResult.Text = r.ToString();
}
private void btn_Cut_Click(object sender, EventArgs e)
{
Button btn = (Button)sender;
textBox.Text = textBox.Text + " " + btn.Text + " ";
}
private void btnMul_Click(object sender, EventArgs e)
{
Button btn = (Button)sender;
textBox.Text = textBox.Text + " " + btn.Text + " ";
}
private void btnDiv_Click(object sender, EventArgs e)
{
Button btn = (Button)sender;
textBox.Text = textBox.Text + " " + btn.Text + " ";
}
private void label1_Click(object sender, EventArgs e)
{
}
private void btn_Point_Click(object sender, EventArgs e)
{
textBox.Text += '.';
}
private void btn_Remove_Click(object sender, EventArgs e)
{
string old = textBox.Text;//取得当前的数据
if (old.Length > 0)
textBox.Text = old.Remove(old.Length - 1);//删掉最后一个字符
}
private void txtResult_TextChanged(object sender, EventArgs e)
{
}
private void Form1_Load(object sender, EventArgs e)
{
if (MessageBox.Show("计算机Demo", "", MessageBoxButtons.YesNo, MessageBoxIcon.Information) == DialogResult.Yes) ;
}
private void process1_Exited(object sender, EventArgs e)
{
}
private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
DialogResult dr = MessageBox.Show("确认退出吗", "提示", MessageBoxButtons.YesNo, MessageBoxIcon.Warning);
if (dr == DialogResult.Yes)
{
e.Cancel = false;
}
else
{
e.Cancel = true;
}
}
private void textBox_TextChanged(object sender, EventArgs e)
{
if (textBox.Text.StartsWith("."))
textBox.Text = textBox.Text.Remove(0, 1);
else if (textBox.Text.IndexOf('.') != textBox.Text.LastIndexOf('.'))
MessageBox.Show("你输入了两个点!!");
}
private void btn_Point_KeyPress(object sender, KeyPressEventArgs e)
{
}
private void btnAdd_Click(object sender, EventArgs e)
{
System.Windows.Forms.Button btn = (System.Windows.Forms.Button)sender;
textBox.Text = textBox.Text + " " + btn.Text + " ";
{
string add = "";
}
}
private void textBox_KeyPress(object sender, KeyPressEventArgs e)
{
//if (!(Char.IsNumber(e.KeyChar) || (e.KeyChar == '.' && (!((TextBox)sender).Text.Trim().Equals(string.Empty)) && ((TextBox)sender).Text.Trim().IndexOf('.') < 1)))
//{
// e.Handled = true;
//}
}
}
}
private void btn_Point_Click(object sender, EventArgs e)
{
if (!textBox.Contains("."))
textBox.Text += '.';
}
看样子你整个算式是放在一个文本框里的，那判断是否已存在小数点就不行了，因为可以输入两个小数；
而且正常都是输入完成开始计算后再进行算式检验，检验有误则报错，让用户修改或重新输入；
所以你应该先把算式的数值与符号拆分，判断数值是否有效，是否是 数值与符号 交替出现；
【以下回答由 GPT 生成】
要避免在C#计算器中连续输入小数点和运算符号，可以进行以下修改：
bool类型的变量isDecimalEntered，用于标记是否已经输入了小数点。bool类型的变量isOperatorEntered，用于标记是否已经输入了运算符号。isOperatorEntered的值。如果为true，则将文本框内容清空，再追加数字。isDecimalEntered的值。如果为false，则追加小数点并将isDecimalEntered设置为true，否则不操作。isOperatorEntered设置为true，再将isDecimalEntered设置为false。以下是修改后的代码：
private bool isDecimalEntered = false; // 标记是否输入了小数点
private bool isOperatorEntered = false; // 标记是否输入了运算符号
// ...
private void btn1_Click(object sender, EventArgs e)
{
if (isOperatorEntered)
{
textBox.Text = ""; // 清空文本框内容
isOperatorEntered = false;
}
textBox.Text += "1";
}
// ...
private void btnDecimal_Click(object sender, EventArgs e)
{
if (!isDecimalEntered)
{
textBox.Text += ".";
isDecimalEntered = true;
}
}
// ...
private void btnOperator_Click(object sender, EventArgs e)
{
isOperatorEntered = true;
isDecimalEntered = false;
// 获取运算符号，并进行相应的计算
}
// ...
这样修改之后，连续输入小数点和运算符号的问题应该得到解决了。
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