Function CutStr(ByVal s As String, ByVal num As Integer) As String
If s.Length <= num Then
Return s
End If
Dim stemp As String = Mid(s, 1, num)
Dim i As Integer = num
While System.Text.Encoding.Default.GetByteCount(stemp) < 2 * num
i = i + 1
stemp = Mid(s, 1, i)
End While
Return stemp
End Function
从此实例检索子字符串。子字符串从指定的字符位置开始且具有指定的长度。
Dim myString As String = "abc"
Dim test1 As Boolean = String.Compare(myString.Substring(2, 1), "c") = 0 ' This is true.
myString.Substring(3, 1) ' This throws ArgumentOutOfRangeException.
Dim test2 As Boolean = String.Compare(myString.Substring(3, 0), String.Empty) = 0 ' This is true.
[C#]
String myString = "abc";
bool test1 = String.Compare(myString.Substring(2, 1), "c") == 0; // This is true.
myString.Substring(3, 1); // This throws ArgumentOutOfRangeException.
bool test2 = String.Compare(myString.Substring(3, 0), String.Empty) == 0; // This is true.