Find Function with RichTextBox with Labels - richtextbox

Question

What I'm trying to do is to make it where the user can type in a textbox and then click on a button and it will search the richtextbox for what they are looking for and if it found something it will change the label.
(Instances)
`
Button = btn_Search
Textbox = InputBox
RichTextBox = rtb
Label = Results`

Answer 1

Use this method, to find any Text inside your RichTextBox.
public int FindMyText(string searchText, int searchStart, int searchEnd)
{
// Initialize the return value to false by default.
int returnValue = -1;
// Ensure that a search string and a valid starting point are specified.
if (searchText.Length > 0 && searchStart >= 0)
{
// Ensure that a valid ending value is provided.
if (searchEnd > searchStart || searchEnd == -1)
{
// Obtain the location of the search string in richTextBox1.
int indexToText = richTextBox1.Find(searchText, searchStart, searchEnd, RichTextBoxFinds.MatchCase);
// Determine whether the text was found in richTextBox1.
if(indexToText >= 0)
{
// Return the index to the specified search text.
returnValue = indexToText;
}
}
}
return returnValue;
}
call this method like this:
var res= FindMyText("hello",0. richTextBox1.Text.Length);
now if res>-1, that means positive match, then you can set your labels i.e.
if(res>-1){
lbl1.Text = "hello found";
}
source here and here

Answer 2

Another method of searching text that is far more clean is as below,but first you need to add
System.Text.RegularExpressions namespace to your project;
private void SearchButton_Click(object sender, EventArgs e)
{
if (textBox1.TextLength >= 1)
{
string word = textBox1.Text;//The text you want to search.
Regex searchterm = new Regex(word);//A Regular Expression is most efficient way of working with text.
MatchCollection matches = searchterm.Matches(richTextBox1.Text);
if (matches.Count >= 1)
{
Results=matches.Count.ToString();//Your label to display match instances.
richTextBox1.SelectAll();
richTextBox1.SelectionBackColor = Color.White;
richTextBox1.DeselectAll();
foreach (Match match in matches)
{
richTextBox1.Select(match.Index, match.Length);
richTextBox1.SelectionBackColor = Color.Orange;
richTextBox1.DeselectAll();
}
}
}
}
This should do the job,furthermore if you want to specify additional search options,replace the line with Regex searchterm with anyone below,
Case Insensitive
Regex searchterm = new Regex(word,RegexOptions.IgnoreCase);
Whole Word Search
Regex searchterm = new Regex(#"\b"+word+"\b");
Case Insensitive and Whole Word Search
Regex searchterm = new Regex(#"\b"+word+"\b",RegexOptions.IgnoreCase);
and one more thing,Regex searches are case-sensitive by default.