I have a C# program that utilizes a find function however it is able to find the word but does not highlights the found word in the richTextBox.
Can someone please advise me on the codes?
Thanks.
Find Function Class Form:
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 Syscrawl
{
public partial class Find_Form : Form
{
FTK_Menu_Browsing_History fmbh = new FTK_Menu_Browsing_History();
public Find_Form()
{
InitializeComponent();
}
public void searchButton_Click(object sender, EventArgs e)
{
string s1 = fmbh.getSearchBrowsing().ToLower();
string s2 = textBoxSearch.Text.ToLower();
if (s1.Contains(s2))
{
MessageBox.Show("Word found!");
this.fmbh.richTextBoxBrowsing.Find(s2);
this.fmbh.richTextBoxBrowsing.SelectionLength = s2.Length;
this.fmbh.richTextBoxBrowsing.SelectionColor = Color.Red;
this.Close();
}
else
{
MessageBox.Show("Word not found!");
}
}
}
}
You need to select what you are looking for first. This:
int offset = s1.IndexOf(s2);
richTextBox1.Select(offset, s2.Length);
After that you can make the whole highlightining. Another tip, to prevent the flickering in the selection process, use this code in your form:
protected override void WndProc(ref Message m)
{
if (m.Msg == 0) {
if (!_doPaint)
return;
}
base.WndProc(ref m);
}
Before selecting anything set _doPaint to false and after the selection set it to true.
Hope I can help!
You need to call s1.IndexOf(s2, StringComparison.CurrentCultureIgnoreCase) to find the position of the match.
Also, it looks like your Find form creates its own instance of the History form; it doesn't use the existing instance.
You should consider accepting a constructor parameter.
Related
I use a GD4430 handheld scanner from the company Datalogic with the included OPOS driver. With the following code I manage to address the scanner. When I start the program, the scanner becomes active and you can scan. But I can not display the results in a TextBox.
Does anyone see where the error lies?
Visual Studio 2010 C#
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 TestRead
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
axOPOSScanner1.BeginInit();
axOPOSScanner1.Open("USBHHScanner");
axOPOSScanner1.ClaimDevice(0);
axOPOSScanner1.DeviceEnabled = true;
axOPOSScanner1.DataEventEnabled = true;
axOPOSScanner1.PowerNotify = 1; //(OPOS_PN_ENABLED);
axOPOSScanner1.DecodeData = true;
}
void axOPOSScanner1_DataEvent(object sender, AxOposScanner_CCO._IOPOSScannerEvents_DataEventEvent e)
{
textBox1.Text = axOPOSScanner1.ScanDataLabel;
textBox2.Text = axOPOSScanner1.ScanData.ToString();
axOPOSScanner1.DataEventEnabled = true;
axOPOSScanner1.DataEventEnabled = true;
}
}
}
Was not the processing of AxOPOSScanner1.BeginInit() on the source originally in Form1.Designer.cs instead of here?
(I am assuming that the source file name is Form1.cs)
As below(in Form1.Designer.cs):
this.axOPOSScanner1 = new AxOposScanner_CCO.AxOPOSScanner();
((System.ComponentModel.ISupportInitialize)(this.axOPOSScanner1)).BeginInit();
this.SuspendLayout();
There is a possibility that the problem has occurred because you moved it to Form1.cs or calling BiginInit() on both Form1.Designer.cs and Form1.cs.
Or, the following processing does not exist in Form1.Designer.cs, or there is a possibility that the specified function name(axOPOSScanner1_DataEvent) is wrong.
this.axOPOSScanner1.DataEvent += new AxOposScanner_CCO._IOPOSScannerEvents_DataEventEventHandler(this.axOPOSScanner1_DataEvent);
In addition:
What you should do is to temporarily store the return value of all the methods, add a process to determine whether the method was executed normally, likewise It is to read the ResultCode property immediately after setting the property(possibly causing an error) and add processing to judge whether the property setting was done normally.
Also, although not related to DataEvent, PowerNotify setting must be done before DeviceEnabled = true.
I am new at C#. I hope someone can help me.
I am programing a small Windows Forms Application.
Two textBoxes and one result label.
For hours I am trying to get from the Strings in the textBoxes a Float Value.
Later some one will write for example 1.25 in TextBox1 and divide it with a value in the second TextBox.
I tryed lot of code. If a code is working (not red underlined) than I get this
Error Message: "Error kind of System.Format.Exception in mscorlib.dll".
"The entered String has wrong format".
How can I fix this?! Or what am I m doing wrong?! Please help. I am a Noob.
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
string a = textBox1.Text;
string b = textBox2.Text;
float num = float.Parse(textBox1.Text);
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
}
}
}
`
If you use the Parse function & an invalid number is entered - then you will get an error message (in the form of an unhandled exception) of the type you described.
You can either implement exception handling :
float num;
try
{
num = float.Parse(textBox1.Text);
}
catch (FormatException)
{
// report format error here
}
you can also catch the out of range & null argument exceptions : https://msdn.microsoft.com/en-us/library/2thct5cb(v=vs.110).aspx
Or use the TryParse method :
float num;
bool NumberOK = float.TryParse(textBox1.Text, out num);
if (!NumberOK)
{
// report error here
}
https://msdn.microsoft.com/en-us/library/26sxas5t(v=vs.110).aspx
So I'm trying to make a simple program in Visual C# that counts the number of "Connected Devices", which can be seen as the amount of buttons clicked.
The code should check which button was clicked and change it's background image. It should also update the count and label on the form.
First of all, here's my code:
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 Device_Storage
{
public partial class Form1 : Form
{
int totalDevices = 0;
public Form1()
{
InitializeComponent();
}
private void addDevice(object sender, EventArgs e)
{
try
{
Button clickedBtn = sender as Button;
Image add_image = Properties.Resources.addDevice;
Image remove_image = Properties.Resources.removeDevice;
if (clickedBtn.BackgroundImage == Properties.Resources.addDevice)
{
clickedBtn.BackgroundImage = remove_image;
totalDevices++;
}
else if (clickedBtn.BackgroundImage == Properties.Resources.removeDevice)
{
clickedBtn.BackgroundImage = add_image;
totalDevices--;
}
updateLabel();
} catch (Exception ex)
{
MessageBox.Show(ex.Message, "An Error Occured");
}
}
private void updateLabel()
{
label1.Text = "Connected devices: " + totalDevices;
}
}
}
(I didn't change any of the using statements yet, I usually do that when I'm finished or am 100% sure I won't be using the namespace)
I can't find anything wrong with the code myself and Visual Studio (2015) doesn't give an error.
When I click a button (there are 36 total buttons) nothing happens, the label doesn't update, the image doesn't change, nothing. I don't even get an error, the program doesn't crash.
If anyone can see what I did wrong and can help me fix it that would be really appreciated.
(Edit: My resources folder contains 2 png files, "addDevice.png" and "removeDevice.png")
(New info: all buttons start with the background image "addDevice.png" as to represent an empty slot)
So im attempting to create a auto typer. And the problem is if i spam the message, And click the application to stop the spam it just freezes up. I as then told i need to use Threads. So i had a read around and this is what i came up with:
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;
using System.Threading;
namespace tf2trade
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public bool started = true;
private void spam()
{
string test = text1.Text;
Thread.Sleep(2000);
while (started == false)
{
foreach (char c in test)
{
SendKeys.Send(c.ToString());
}
SendKeys.Send("{ENTER}");
}
}
Thread test = new Thread(spam);
private void richTextBox1_TextChanged(object sender, EventArgs e)
{
}
private void submit_Click(object sender, EventArgs e)
{
if (started == true)
{
started = false;
submit.Text = "Stop";
submit.Refresh();
spam();
}
else
{
started = true;
submit.Text = "Start";
}
}
}
}
Now this code gives me the error:
A field initializer cannot reference the non-static field, method, or property 'tf2trade.Form1.spam()'
What did i do wrong? :(
Thanks in advance,
Alana.
Honestly I wouldn't waste your time troubleshooting this error. Instead, consider using one of the existing approaches to writing multi-threaded applications in .NET . The technology you use will depend on the type of problem you are trying to solve. For short/quick tasks consider using:
thread pool
.net task library
If you are creating a "long" running task you could create 1 or more native threads, but I wouldn't recommend doing this until you have a better understanding of what you are doing. There are a lot of pitfalls. For example, A lot of developers think more threads equals better performance... this is not true.
REFERENCES
thread pool:
http://msdn.microsoft.com/en-us/library/system.threading.threadpool(v=vs.110).aspx
tasks: http://msdn.microsoft.com/en-us/library/dd460717(v=vs.110).aspx
native thread: http://msdn.microsoft.com/en-us/library/system.threading.thread(v=vs.110).aspx
With the below code, I've tested it out and the loading of the form works fine standalone, but when the program goes to check if a file exists, the form doesn't load properly and I'm at a loss as to what to do. Is there another method of checking to see if a file exists that I could use in this instance?
EDIT I've made a new 'startup' form to run the file exists check, but it still doesn't work. Again the form loads, but the contents of the form don't and the form itself freezes.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Timers;
using System.IO;
using System.Collections;
using System.Runtime.InteropServices;
using Microsoft.Win32;
using System.Diagnostics;
using System.Windows.Input;
namespace program1
{
public partial class Startup : Form
{
public Startup()
{
InitializeComponent();
}
private void Startup_Load(object sender, EventArgs e)
{
notifyIcons norm = new notifyIcons();
Settings set = new Settings();
set.Show();
string curFile = Environment.CurrentDirectory + "\\age.txt";
if (File.Exists(curFile))
{
norm.Show();
this.Close();
}
else
{
set.Show();
for (;;)
{
if (File.Exists(curFile)) norm.Show(); this.Close();
Application.DoEvents();
}
}
}
}
}
I have no idea what this code is supposed to do.. but I can tell you why its not working.
while (ageFileExists)
That is never false. Therefore, your loop will continually loop... forever. You need to set it false somehow in the loop. I have no idea what sort of rules govern that though.
The reason the form doesn't load is because the loop never exits.. and so the message loop that makes the window do anything can never continue processing window messages.
If you can give more context around what you're trying to do I could help you with a proper solution. As it stands though, I can only see the problem.
while(ageFileExists)
{
if (File.Exists(curFile)) ageFileExists = true;
set.WindowState = FormWindowState.Normal;
}
If that file exists you have an infinite loop. You never set ageFileExists to false and that loop does nothing at all. And where does that label go? I seriously doubt you need to be using goto. Your code doesn't make much sense as it stands.
By using the following code in the main form, it seemed to work a treat! I think the critical part was Application.DoEvents();
Thanks for all of your assistance
InitializeComponent();
set.Show();
set.WindowState = FormWindowState.Minimized;
string curFile = Environment.CurrentDirectory + "\\age.txt";
if (File.Exists(curFile)) goto Labelx;
set.WindowState = FormWindowState.Normal;
for (; ; ) { Application.DoEvents(); if (File.Exists(curFile)) break; }
set.WindowState = FormWindowState.Minimized;
Labelx:TextReader reader = File.OpenText(Environment.CurrentDirectory + "\\age.txt");