从字符串中提取字符

Question

我想从条形码中的字符串中提取字符：

 <TextBox x:Name="Original_Code_TxtBox"
                     Text="£C131020019969120792A32305VPFE193015"/>

我想要：仅A32305VPFE1部分。但事实是，此字符串永远不会具有相同的长度。可以是：A32305或A32305F ...

那么我该如何编写类似于以下代码的代码：

private void Delimite_Btn_Click(object sender, RoutedEventArgs e)
{
    int beginstring = 20;
    int endstring = Original_Code_TxtBox.Text.Length - 5; // because the last 5 characters never change
    Original_Code_TxtBox.Select(beginstring, endstring);
}

Answer 1

private static readonly int beginIndex = 20;

private void Delimite_Btn_Click(object sender, RoutedEventArgs e)
{
    string barcode = Original_Code_TxtBox.Text;
    int endIndex = barcode.Length - 5;

    if (endIndex > beginIndex)
    {
        var selectedText = barcode.Substring(beginIndex, endIndex - beginIndex);
    }
}

Answer 2

class Program
    {
        public static void Main(string[] args)
        {
            string s = "£C131020019969120792A32305VPFE193015";
            string newstring = s.Substring(s.Length - 16, 6);
            Console.WriteLine(newstring);
        }
    }

结果：“ A32305”