Develop Reference

Taking Value From Text Box Into Total (VS - C#)

I am new to the C# scene, so don't really have much knowledge - This is my first project.
I am looking to create a very basic calorie counter, which eventually will include other functions.
Here's what I have so far;
I want to know how to take the value from the text box on the click of the 'Add' button - Which adds to the total value (bottom right)
I'm looking for any tips/videos to help so anything is appreciated.
TIA

I made a simple implementation for you, you could refer to it:
using System;
using System.Windows.Forms;
namespace WindowsFormsApp2
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void textBox1_KeyUp(object sender, KeyEventArgs e)
{
bool Flag = Int32.TryParse(textBox1.Text, out int result);//Determine if it is a number
if (textBox1.Text == "")//If it is null, falg takes true and skips the next judgment
{ Flag = true; }
else if (!Flag)
{
MessageBox.Show("Input Error");
textBox1.Text = null;
}
}
private void button1_Click(object sender, EventArgs e)
{
Int32.TryParse(textBox1.Text, out int result);
int total =result + Convert.ToInt32(label3.Text);
label3.Text = total.ToString();
}
private void button2_Click(object sender, EventArgs e)
{
label3.Text = "0";
}
}
}

Calculator in C# input from keyboard using "&" in text property

I'm developing a calculator in visual studio 2017. Everything is working fine, but input from keyboard isn't working properly.
I use "&" in text property of a button, and it works, but problem is that it's printing on the screen like "&1 + &2". I attach a code and images so you guys can see what's happening.
1 - result picture
2 - usage of "&" symbol
Thanks in advance,
Best regards,
Ram
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 Calculator
{
public partial class Form1 : Form
{
Double resultado_value = 0; // result is zero in the beginning
String operationPerformed = "";
bool is_pressed = false;
public Form1()
{
InitializeComponent();
}
private void button_click(object sender, EventArgs e)
{
if ((textBox_Result.Text == "0") || (is_pressed))
textBox_Result.Clear();
is_pressed = false;
Button button = (Button)sender;
if (button.Text == ".") //to avoid repetitive dots
{
if(!textBox_Result.Text.Contains("."))
textBox_Result.Text = textBox_Result.Text + button.Text;
}else
textBox_Result.Text = textBox_Result.Text + button.Text;
}
private void operator_click(object sender, EventArgs e)
{
Button button = (Button)sender;
if (resultado_value != 0) //if result value not equal to zero
{
button15.PerformClick();
operationPerformed = button.Text;
labelCurrentOperation.Text = resultado_value + " " + operationPerformed;
is_pressed = true;
}
else
{
operationPerformed = button.Text;
resultado_value = Double.Parse(textBox_Result.Text);
labelCurrentOperation.Text = resultado_value + " " + operationPerformed;
is_pressed = true;
}
}
//Clear entry
private void button4_Click(object sender, EventArgs e)
{
textBox_Result.Text = "0";
}
//button Clear
private void button5_Click(object sender, EventArgs e)
{
// this.BackColor = System.Drawing.Color.White;//can't find color "control"
textBox_Result.Text = "0";
resultado_value = 0;
}
// equal button
private void button15_Click(object sender, EventArgs e)
{
switch (operationPerformed)
{
case "+":
// this.BackColor = System.Drawing.Color.Red;//form change color to red
textBox_Result.Text = (resultado_value + Double.Parse(textBox_Result.Text)).ToString();
break;
case "-":
// this.BackColor = System.Drawing.Color.Aqua;
textBox_Result.Text = (resultado_value - Double.Parse(textBox_Result.Text)).ToString();
break;
case "X":
// this.BackColor = System.Drawing.Color.AliceBlue;
textBox_Result.Text = (resultado_value * Double.Parse(textBox_Result.Text)).ToString();
break;
case "÷":
// this.BackColor = System.Drawing.Color.BlueViolet;
textBox_Result.Text = (resultado_value / Double.Parse(textBox_Result.Text)).ToString();
break;
default:
break;
}
resultado_value = Double.Parse(textBox_Result.Text);
labelCurrentOperation.Text = "";
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void labelCurrentOperation_Click(object sender, EventArgs e)
{
}
}
}

If I understand what you are trying to do correctly then what you want to do is catch keypresses at the Form level. If this is what you want you should set the KeyPreview Property of your Form to true and override the OnKeyPress Method of the Form or add an Event Handler of KeyPressed and assign this to the Forms KeyPressed Event and do your thing there.
If you want me to provide an example let me know.
Ram Pawar I have written a quick example for you.
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Formkeypress
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
KeyPreview = true;
}
protected override void OnKeyPress(KeyPressEventArgs e)
{
base.OnKeyPress(e);
if (e.KeyChar == 'r') BackColor = Color.Red;
if (e.KeyChar == 'b') BackColor = Color.Blue;
if (e.KeyChar == 'g') BackColor = Color.Green;
}
}
}
Basicly if you type 'r' here the Form will change its Background color to Red. Typing 'b' will change it to Blue, typing 'g' will change it to Green.
Please note that you have to set KeyPreview to true in the constructor for this to work.
I override the OnKeyPress event here as this is the prefered way to add logic to an event when deriving from a Control or Form. You can however just attach a KeyPress event handler to the Form if you wish with the same code block as the OnKeyPress method.
Also rermove the '&'s from your Text Properties.
Hope this help
Danny

set a shortcut key for a button in C# [duplicate]

This question already has answers here:
Best way to implement keyboard shortcuts in a Windows Forms application?
(9 answers)
Closed 6 years ago.
i have a point of sale program made with C#
when pressing submit button it submit the sale and print the invoice
i want to make a shortcut for it so when i press a shortcut key on the keyboard
it does the buttons work
here is my button Code:
private void btnCompleteSalesAndPrint_Click(object sender, EventArgs e)
{
DialogResult result = MessageBox.Show("Do you want to Complete Sale and Print?\n\n -If you need any item [duplicate] (1 item 2 piece) \n -Please Increase item Quantity \n ----- by clicking + sign ", "Yes or No", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2);
if (result == DialogResult.Yes)
{
if (txtPaidAmount.Text == "")
{
MessageBox.Show("Sorry ! you have not enough product \n Please Purchase product or Increase Product Quantity");
// detail_info go = new detail_info();
// go.ShowDialog();
}
else
{
try
{
sales_item();
//Save payment info into sales_payment table
payment_item();
// 5 % Rewards Point add to customer Account for total Payable amount
AddCredit();
PrintPage mkc = new PrintPage();
mkc.saleno = txtInvoice.Text;
mkc.vat = txtVATRate.Text;
mkc.dis = txtDiscountRate.Text;
mkc.paidamt = txtPaidAmount.Text;
mkc.subtotal = lblsubtotal.Text;
mkc.ShowDialog();
showincrement();
ClearForm2();
}
catch (Exception exp)
{
MessageBox.Show(exp.Message);
}
}
}
}

How about using the KeyDown event on the form? Say for example that the shortcut key is "E".
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.E)
{
btnCompleteSalesAndPrint_Click(sender, new EventArgs());
}
}
However this wouldn't really work with multiple keys, so instead you may want to use a system that allows you to check if a certain key is pressed instead. Say that "CTRL" + "E" is the shortcut. Use the "PresentationCore" library in order to access the "System.Windows.Input" namespace.
using System.Windows.Input;
//[...]
private bool ControlPressed//Returns true if the left control button or the right control button is pressed. Returns false if neither are pressed.
{
get
{
return Keyboard.IsKeyDown(Key.LeftCtrl) || Keyboard.IsKeyDown(Key.RightCtrl);
}
}
private bool E_Pressed//Boolean that returns true if "E" is pressed and false if it isn't.
{
get
{
return Keyboard.IsKeyDown(Key.E);
}
}
And to check at regular intervals to see if these keys are pressed.
public Form1()
{
InitializeComponent();
Timer timer = new Timer();//Create new instance of Timer.
timer.Interval = 1;
timer.Tick += new EventHandler(timer_Tick);//Set an eventhandler to occur after each 1000th of a second.
timer.Enabled = true;
}
private void timer_Tick(object sender, EventArgs e)
{
if (ControlPressed && E_Pressed)
{
btnCompleteSalesAndPrint_Click(sender, new EventArgs());
}
}
Codf bflow:
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;
using System.Windows.Input;
namespace hmmmhmh
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
Timer timer = new Timer();
timer.Interval = 1;
timer.Tick += new EventHandler(timer_Tick);
timer.Enabled = true;
}
private void timer_Tick(object sender, EventArgs e)
{
if (Control_Pressed && F_Pressed)
{
button1_Click(sender, e);
}
}
private bool Control_Pressed
{
get
{
return Keyboard.IsKeyDown(Key.LeftCtrl) || Keyboard.IsKeyDown(Key.RightCtrl);
}
}
private bool F_Pressed
{
get
{
return Keyboard.IsKeyDown(Key.E);
}
}
private void button1_Click(object sender, EventArgs e)
{
MessageBox.Show("hlhlh");
}
}
}

How can I implement effective Undo/Redo into my WinForms application?

I have a WinForm text editor.
I would like to be able to allow the user to undo and redo changes in the Rich Text Box, like they can in Microsoft Word.
I have spent the past week or so researching how to do this, and most results seem to be regarding graphics applications.
The standard richTextBox1.Undo(); gives disappointing results, as it undoes everything that the user has written.
Does anybody have any idea how I could implement effective undo/redo? Preferably one which undoes/redoes the action word-by-word as opposed to character-by-character.

This is a very basic idea, and I'm sure that many improvements could be made.
I would create a String Array and incrementally store the value of the RichTextBox (In the TextChanged event, under your own conditions) in the array. As you store the value, increment the value of a counter, say stackcount. When the user undoes, decrement the stackcount and set the RichTextBox.Text = array(stackcount). If they redo, then increment the value of the counter and set the value again. If they undo and then change the text, then clear all values onwards.
I am sure that many other people may have better suggestions/changes for this, so please post in comments and I will update, or edit it yourself!
Example in C#
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace RedoUndoApp
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public string[] RTBRedoUndo;
public int StackCount = 0;
public int OldLength = 0;
public int ChangeToSave = 5;
public bool IsRedoUndo = false;
private void Form1_Load(object sender, EventArgs e)
{
RTBRedoUndo = new string[10000];
RTBRedoUndo[0] = "";
}
private void undo_Click(object sender, EventArgs e)
{
IsRedoUndo = true;
if (StackCount > 0 && RTBRedoUndo[StackCount - 1] != null)
{
StackCount = StackCount - 1;
richTextBox1.Text = RTBRedoUndo[StackCount];
}
}
private void redo_Click(object sender, EventArgs e)
{
IsRedoUndo = true;
if (StackCount > 0 && RTBRedoUndo[StackCount + 1] != null)
{
StackCount = StackCount + 1;
richTextBox1.Text = RTBRedoUndo[StackCount];
}
}
private void richTextBox1_TextChanged(object sender, EventArgs e)
{
if (IsRedoUndo == false && richTextBox1.Text.Substring(richTextBox1.Text.Length - 1, 1) == " ")//(Math.Abs(richTextBox1.Text.Length - OldLength) >= ChangeToSave && IsRedoUndo == false)
{
StackCount = StackCount + 1;
RTBRedoUndo[StackCount] = richTextBox1.Text;
OldLength = richTextBox1.Text.Length;
}
}
private void undo_MouseUp(object sender, MouseEventArgs e)
{
IsRedoUndo = false;
}
private void redo_MouseUp(object sender, MouseEventArgs e)
{
IsRedoUndo = false;
}
}
}

One way to do this is use the TextChanged event to periodically store the contents of richtextbox.text in an array or list, as a stack. When you undo, "pop the stack" and copy the most recent version on the stack into richtextbox.text.
TextChange can determine whether a change should be saved onto the stack, whether a new word, line, or character.

DoDragDrop from standard Label not working

I can't figure out why attempting to drag text from a standard Label to Notepad (or any other control accepting text) doesn't work. I've looked at documentation and examples and I'm not seeing the problem. The cursor remains a circle with a line through it and if I register a FeedBack callback the event is always NONE. Creating a standard Windows Forms Application, dropping a Label control and registering MouseDown & MouseMove events I have this code where I call label1.DoDragDrop (label1, DragDropEffects.All | DragDropEffects.Link). Any help would be appreciated.
Here is my form code:
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 DragDropLabel
{
public partial class Form1 : Form
{
Point m_ClickLocation;
bool _bDragging = false;
public Form1()
{
InitializeComponent();
}
private void OnLabelMouseDown(object sender, MouseEventArgs e)
{
m_ClickLocation = e.Location;
_bDragging = true;
}
private void OnLabelMouseMove(object sender, MouseEventArgs e)
{
if (_bDragging)
{
Point pt = e.Location;
Size dragSize = SystemInformation.DragSize;
if (Math.Abs(pt.X - m_ClickLocation.X) > dragSize.Width / 2 ||
Math.Abs(pt.Y - m_ClickLocation.Y) > dragSize.Height / 2)
{
DragDropEffects rc = label1.DoDragDrop(label1, DragDropEffects.All | DragDropEffects.Link);
_bDragging = false;
}
}
}
}
}

First, change
DragDropEffects rc = label1.DoDragDrop(label1, DragDropEffects.All | DragDropEffects.Link);
to
label1.DoDragDrop(label1.Text, DragDropEffects.Copy);
Second, you must prepare your drop target. Lets assume, it is textbox. Here is exmple extension method which will allow to cofigure any textbox by calling MyTextBox.EnableTextDrop():
static class TextBoxExtensions
{
public static void EnableTextDrop(this TextBox textBox)
{
if(textBox == null) throw new ArgumentNullException("textBox");
// first, allow drop events to occur
textBox.AllowDrop = true;
// handle DragOver to provide visual feedback
textBox.DragOver += (sender, e) =>
{
if(((e.AllowedEffect & DragDropEffects.Copy) == DragDropEffects.Copy) &&
e.Data.GetDataPresent(typeof(string)))
{
e.Effect = DragDropEffects.Copy;
}
};
// handle DragDrop to set text
textBox.DragDrop += (sender, e) =>
{
if(((e.AllowedEffect & DragDropEffects.Copy) == DragDropEffects.Copy) &&
e.Data.GetDataPresent(typeof(string)))
{
((TextBox)sender).Text = (string)e.Data.GetData(typeof(string));
}
};
}
}

Standard edit controls (textboxes) do not support drag&drop and will not accept any dropped text.