How do I add second number to a texbox after emptying it?Calculator

Question

1.00/5 (1 vote)

See more:

C#

Button[] numbers = new Button[10];
Button[] operators = new Button[5];
Button[] soperators = new Button[15];
string[] symbols = new string[]{ "+", "-", "*", "/" ,"="};
string[] scientific = new string[] {"sin","cos","tan","log","e","x2","^","!","(",")","[","]","Ans","rad","exp" };
public Form1()
{
    InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{
    for (int i = 0; i < 10; i++)
    {
        if (i < 9)
        {
            numbers[i] = new Button();
            numbers[i].Text = (i + 1).ToString();
            numbers[i].Size = new Size(40, 40);
        }
        else
        {
            numbers[9] = new Button();
            numbers[9].Text = "0";
            numbers[9].Size = new Size(130, 40);
        }
        numbers[i].Click += btn_Click;
        this.flowLayoutPanel2.Controls.Add(numbers[i]);
    }
    for (int i = 0; i < 5; i++)
    {
        operators[i] = new Button();
        operators[i].Text = symbols[i];
        operators[i].Click += op_Click;
        this.flowLayoutPanel3.Controls.Add(operators[i]);
    }

    for (int i = 0; i < 15; i++)
    {
        soperators[i] = new Button();
        soperators[i].Text = scientific[i];
        soperators[i].Size = new Size(50, 30);
        this.flowLayoutPanel1.Controls.Add(soperators[i]);
    }
}
public void btn_Click(object sender,EventArgs e)
{
    Button b = (Button)sender;
    textBox1.Text = textBox1.Text + b.Text;
}
int firstNo;int secondNo=0;
string si;
public void op_Click(object sender,EventArgs e)
{
    Int32 result;
    Button b = (Button)sender;
    si = b.Text;
    firstNo = int.Parse(textBox1.Text);
    result = firstNo;
    textBox1.Text = "";
    secondNo = int.Parse(textBox1.Text);
    if (textBox1.Text!= "")
    {
        switch(si)
        {
            case "+":
                result = firstNo + secondNo;
                break;
            case "-":
                result = firstNo - secondNo;
                break;
            case "*":
                result = firstNo * secondNo;
                break;
            case "/":
                result = firstNo / secondNo;
                break;
            case "=":
                textBox1.Text = result.ToString();
                break;
        }

    }
}

Posted 25-Oct-14 7:05am

Member 10528646

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

BillWoodruff · Accepted Answer · 2014-10-25T10:28:00

I think you are very close to being able to make this work: just focus on the fact that the moment one of the +-*/ operator buttons is pressed you need:

1. to store the value in the TextBox, as well as which operator was pressed

2. when the = operator button is pressed you need to get the second value, and then execute the stored operator, using the first value entered

I suggest you make the = operator button Click EventHandler a separate function in order to do this. I also suggest you switch to using 'double, not Int32, since you will lose all fractional values using Int32.

Here's a rough outline in psuedo-code:

C#

private double firstValue;

private string operatorToExecute;

private void ActionOperator_Click((object sender, EventArgs e))
{
    operatorToExecute = // get the operator from the button's Text property

    firstValue = // parse the entry TextBox to get the first value

    // clear the entry TextBox
}

private void EqualOperator_Click()
{
    // do you need to check and see if you have a valid action operator ?
    // do you need to check and see if you have a valid first value ?
    // do you need to handle more than one click at a time of this button ?
    
    double secondValue = // get the second value from the entry TextBox
    
    // switch statement goes here to execute action operator
    
    // display result or error message
}