Incremental Search

In This Topic

With True DBGrid, you can easily perform search either on the whole grid or just a specific column. Incremental search for a column in the grid, positions a grid to that row if a match is found. The incremental searching feature specifically uses the grid's KeyPress event and the grid's indexer to retrieve and compare data for the particular column.

Let's say the user wants to search for entries in a column using incremental search, for this purpose, the user can add a Timer component to the form, and then set the KeyPress and Tick events.

Complete the following steps:

Add a Timer component from the Visual Studio Toolbox to the form.

Set the Timer's Interval property to 1 second.

In the Designer

Locate the Interval property for Timer1 in the Properties window and set it to 1000.

In Code

Add the following code to the Form_Load event:

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this.timer1.Interval = 1000;

Add the KeyPress event:

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private void c1TrueDBGrid1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) { // we're handling the keystroke e.Handled = true; this._searchString += e.KeyChar; int count = this.c1TrueDBGrid1.Splits[0].Rows.Count; int start = this.c1TrueDBGrid1.Row; int current = (start + 1) % count; // we'll stop if we get back to our starting position while( current != start ) { // get the value string s = this.c1TrueDBGrid1[current, this.c1TrueDBGrid1.Col].ToString(); // if we find a match, we're done if(!string.IsNullOrEmpty(s) && s.Length >= _searchString.Length && s.Substring(0, _searchString.Length).ToUpper() == _searchString.ToUpper() ) break; // search the next row, wrap if we need too current = (current + 1) % count; } // update the grid's current row this.c1TrueDBGrid1.Row = current; // clears the search string this.timer1.Enabled = true; }

Copy Code

private void c1TrueDBGrid1_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e)
        {
            // we're handling the keystroke
            e.Handled = true;
            this._searchString += e.KeyChar;
            int count = this.c1TrueDBGrid1.Splits[0].Rows.Count;
            int start = this.c1TrueDBGrid1.Row;
            int current = (start + 1) % count;
            // we'll stop if we get back to our starting position
            while( current != start )
            {
                // get the value
                string s = this.c1TrueDBGrid1[current, this.c1TrueDBGrid1.Col].ToString();
                // if we find a match, we're done
                if(!string.IsNullOrEmpty(s) && s.Length >= _searchString.Length && s.Substring(0, _searchString.Length).ToUpper() == _searchString.ToUpper() )
                    break;
                // search the next row, wrap if we need too
                current = (current + 1) % count;
            }
            // update the grid's current row
            this.c1TrueDBGrid1.Row = current;
            // clears the search string
            this.timer1.Enabled = true;
        }

Add the Tick event for the timer:

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private void timer1_Elapsed(object sender, System.Timers.ElapsedEventArgs e) { this._searchString = string.Empty; this.timer1.Enabled = false; }

As the user types, the search will highlight the cell containing that letter. If more than one entry begins with the same letter, typing the next letter will highlight the entry with those letters.

Note: After 1 second, the search string will reset.