String.StartsWith Method (String)
Determines whether the beginning of this instance matches the specified string.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Parameters
- value
- Type: System.String
The string to compare.
Return Value
Type: System.Booleantrue if value matches the beginning of this string; otherwise, false.
| Exception | Condition |
|---|---|
| ArgumentNullException | value is Nothing. |
This method compares value to the substring at the beginning of this instance that is the same length as value, and returns an indication whether they are equal. To be equal, value must be an empty string (String.Empty), a reference to this same instance, or match the beginning of this instance.
This method performs a word (case-sensitive and culture-sensitive) comparison using the current culture.
Notes to CallersStarting in Silverlight 4, the behavior of the String.StartsWith(String) method has changed. In Silverlight 4, it performs a case-sensitive and culture-sensitive comparison using the current culture to determine whether the current instance begins with value. This conforms to the behavior of the String.StartsWith(String) method in the full .NET Framework. In Silverlight 2 and Silverlight 3, String.StartsWith(String) performs an ordinal comparison using the current culture. If the common language runtime determines that a Silverlight-based application was compiled against Silverlight 2 or Silverlight 3, it performs an ordinal comparison; otherwise, it performs a culture-sensitive comparison.
The following code example demonstrates how you can use the StartsWith method.
Public Class Example Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock) Dim strSource As String() = {"<b>This is bold text</b>", _ "<H1>This is large Text</H1>", _ "<b><i><font color = green>This has multiple tags</font></i></b>", _ "<b>This has <i>embedded</i> tags.</b>", _ "<This line simply begins with a lesser than symbol, it should not be modified"} ' process a string that contains html tags ' this sample does not remove embedded tags (tags in the middle of a line) outputBlock.Text &= "The following lists the items before the tags have been stripped:" & vbCrLf outputBlock.Text &= "-----------------------------------------------------------------" & vbCrLf ' print out the initial array of strings Dim s As String For Each s In strSource outputBlock.Text &= s & vbCrLf Next s outputBlock.Text &= vbCrLf outputBlock.Text &= "The following lists the items after the tags have been stripped:" & vbCrLf outputBlock.Text &= "----------------------------------------------------------------" & vbCrLf ' print out the array of strings For Each s In strSource outputBlock.Text &= StripStartTags(s) & vbCrLf Next s End Sub 'Main Private Shared Function StripStartTags(ByVal item As String) As String ' try to find a tag at the start of the line using StartsWith If item.Trim().StartsWith("<") Then ' now search for the closing tag... Dim lastLocation As Integer = item.IndexOf(">") If lastLocation >= 0 Then ' remove the identified section, if it is a valid region item = item.Substring((lastLocation + 1)) End If End If Return item End Function 'StripStartTags End Class 'EndsWithTest
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.