I am designing a basic calculator using C#. I am facing difficulties while I am entering a decimal point. Example, if I am entering .8 then it gives me 0.8 which is correct if there is nothing on the display screen but after that if I am entering the decimal symbol, then also it accepts it that is 0.8….. I want only one decimal symbol to be accepted for one number. My code is
private void btn_Decimal_Click(object sender, EventArgs e)
{
if (txt_Result.Text == "" || LastcharIssymbol==true)
{
txt_Result.Text = txt_Result.Text + 0 + ".";
}
else
txt_Result.Text = txt_Result.Text + ".";
}
Here, if I am entering 0.9.999 then also it accepts and if I am entering 999….. then also it accepts. I want only one decimal symbol to be accepted for one number that is 999.999. Please help me. Also I am adding two additional labels that can show the current system date and time. I am unable to show the date as well as the time but I am able to show the date and time using VB.Net. I don’t know where I am getting the errors. My whole code is
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace CS_Calculator
{
public partial class Form1 : Form
{
Boolean LastcharIssymbol {get;set;}
string op;
double a, memory;
public Form1()
{
InitializeComponent();
}
private void btn_1_Click(object sender, EventArgs e)
{
txt_Result.Text = txt_Result.Text + "1";
LastcharIssymbol= false;
}
private void btn_2_Click(object sender, EventArgs e)
{
txt_Result.Text = txt_Result.Text + "2";
LastcharIssymbol = false;
}
private void btn_3_Click(object sender, EventArgs e)
{
txt_Result.Text = txt_Result.Text + "3";
LastcharIssymbol = false;
}
private void btn_4_Click(object sender, EventArgs e)
{
txt_Result.Text = txt_Result.Text + "4";
LastcharIssymbol = false;
}
private void btn_5_Click(object sender, EventArgs e)
{
txt_Result.Text = txt_Result.Text + "5";
LastcharIssymbol = false;
}
private void btn_6_Click(object sender, EventArgs e)
{
txt_Result.Text = txt_Result.Text + "6";
LastcharIssymbol = false;
}
private void btn_7_Click(object sender, EventArgs e)
{
txt_Result.Text = txt_Result.Text + "7";
LastcharIssymbol = false;
}
private void btn_8_Click(object sender, EventArgs e)
{
txt_Result.Text = txt_Result.Text + "8";
LastcharIssymbol = false;
}
private void btn_9_Click(object sender, EventArgs e)
{
txt_Result.Text = txt_Result.Text + "9";
LastcharIssymbol = false;
}
private void btn_0_Click(object sender, EventArgs e)
{
txt_Result.Text = txt_Result.Text + "0";
LastcharIssymbol = false;
}
private void btn_Decimal_Click(object sender, EventArgs e)
{
if (txt_Result.Text == "" || LastcharIssymbol==true)
{
txt_Result.Text = txt_Result.Text + 0 + ".";
}
else
txt_Result.Text = txt_Result.Text + ".";
}
private void btn_Plus_Click(object sender, EventArgs e)
{
if(txt_Result.Text=="" || LastcharIssymbol)
{
MessageBox.Show("Please Enter first number to perform the addition operation.");
}
else
{
op = "+";
txt_Result.Text = txt_Result.Text + op;
LastcharIssymbol=true;
}
}
private void btn_Minus_Click(object sender, EventArgs e)
{
if (txt_Result.Text == "" || LastcharIssymbol)
{
MessageBox.Show("Please enter first number to erform the substraction operation.");
}
else
{
op = "-";
txt_Result.Text = txt_Result.Text + op;
LastcharIssymbol = true;
}
}
private void btn_Division_Click(object sender, EventArgs e)
{
if (txt_Result.Text == "" || LastcharIssymbol)
{
MessageBox.Show("Please enter first number to perform the division operation.");
}
else
{
op = "/";
txt_Result.Text = txt_Result.Text + op;
LastcharIssymbol = true;
}
}
private void btn_Mult_Click(object sender, EventArgs e)
{
if (txt_Result.Text == "" || LastcharIssymbol)
{
MessageBox.Show("Please enter first number to perform the multiplication operation.");
}
else
{
op = "*";
txt_Result.Text = txt_Result.Text + op;
LastcharIssymbol = true;
}
}
private void btn_Equal_Click(object sender, EventArgs e)
{
}
private void button4_Click(object sender, EventArgs e)
{
txt_Result.Text = "";
}
private void btn_Clear_All_Click(object sender, EventArgs e)
{
txt_Result.Text = "";
op = "";
a = 0;
memory = 0;
}
private void btn_Memory_Click(object sender, EventArgs e)
{
memory = Convert.ToDouble(txt_Result.Text);
}
private void btn_Show_Memory_Click(object sender, EventArgs e)
{
txt_Result.Text = memory.ToString();
}
}
}
for the case you have text like ‘11.9+12’ which has operations in it you can do the following