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ListBox.FindString Method (String, Int32)

Finds the first item in the ListBox that starts with the specified string. The search starts at a specific starting index.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

'Declaration
Public Function FindString ( _
	s As String, _
	startIndex As Integer _
) As Integer

Parameters

s
Type: System.String

The text to search for.

startIndex
Type: System.Int32

The zero-based index of the item before the first item to be searched. Set to negative one (-1) to search from the beginning of the control.

Return Value

Type: System.Int32
The zero-based index of the first item found; returns ListBox.NoMatches if no match is found.

ExceptionCondition
ArgumentOutOfRangeException

The startIndex parameter is less than zero or greater than or equal to the value of the Count property of the ListBox.ObjectCollection class.

The search performed by this method is not case-sensitive. The search looks for words that partially match the specified search string parameter, s. You can use this method to search for the first item that matches the specified string at the specified starting index within the list of items for the ListBox. You can then perform tasks such as removing the item that contains the search text by using the Remove method or changing the item's text. This method is typically used after a call has been made using the version of this method that does not specify a starting index. Once an initial item has been found in the list, this method is typically used to find further instances of the search text by specifying the index position in the startIndex parameter of the item after the first found instance of the search text. If you want to perform a search for an exact word match instead of a partial match, use the FindStringExact method.

NoteNote

When the search reaches the bottom of the ListBox, it continues searching from the top of the ListBox back to the item specified by the startIndex parameter.

The following code example demonstrates how to use the FindString method to search for all instances of the search text in the items of the ListBox. The example uses the version of the FindString method that enables you to specify a starting search index from which to do a continual search of all items in the ListBox. The example also demonstrates how to determine when the FindString method begins searching from the top of the list after it reaches the bottom of the list of items to prevent a recursive search. Once items are found in the ListBox, they are selected using the SetSelected method.

Private Sub FindAllOfMyString(ByVal searchString As String)
   ' Set the SelectionMode property of the ListBox to select multiple items.
   listBox1.SelectionMode = SelectionMode.MultiExtended

   ' Set our intial index variable to -1. 
   Dim x As Integer = -1
   ' If the search string is empty exit. 
   If searchString.Length <> 0 Then 
      ' Loop through and find each item that matches the search string. 
      Do 
         ' Retrieve the item based on the previous index found. Starts with -1 which searches start.
         x = listBox1.FindString(searchString, x)
         ' If no item is found that matches exit. 
         If x <> -1 Then 
            ' Since the FindString loops infinitely, determine if we found first item again and exit. 
            If ListBox1.SelectedIndices.Count > 0 Then 
               If x = ListBox1.SelectedIndices(0) Then 
                  Return 
               End If 
            End If 
            ' Select the item in the ListBox once it is found.
            ListBox1.SetSelected(x, True)
         End If 
      Loop While x <> -1
   End If 
End Sub

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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