CODEWITHSUNDEEP
c#asp.netregex
Developer
Developer

Reputation: 8636

How can I exclude some pattern using regex

Hi all I using the following Regex to extract the control form a form

string MessageBody = String.Empty;
string filePath = System.Web.HttpContext.Current.Request.PhysicalApplicationPath;
filePath = filePath + "WebForm8.aspx";
using (StreamReader sr = new StreamReader(filePath))
{
   MessageBody = sr.ReadToEnd();
   MatchCollection mLabelCollection1 = Regex.Matches(MessageBody, "(?<openingtag><asp:Label.*?>)(?<content>.*?)(?<closingtag><.*?/asp:Label>)", RegexOptions.Singleline);
}

This is working fine but I need to extract the labels which are on the form and exclude the labels which are in some other external controls like Gridview and all

This is my aspx part

<asp:Label ID="lbl" runat="server"></asp:Label>
<asp:GridView runat="server">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:Label ID="lblGrid" runat="server"></asp:Label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

I need to exclude the Gridview label in my regex

Update as per Alex answer enter image description here

<asp:Label ID="lbl" runat="server"></asp:Label>
<asp:GridView runat="server">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:Label ID="lblGrid" runat="server"></asp:Label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

from the above design I need to extract only the labels which are placed directly and need to exclude the labels from Gridview or any external controls the sample output after regex should be <asp:Label ID="lbl" runat="server"></asp:Label>

Upvotes: 0

Views: 170

Answers (1)

Stephan
Stephan

Reputation: 43013

Solution

(?<unwanted><asp:GridView .*?>.*?(?<openingtag><asp:Label.*?>)(?<content>.*?)(?<closingtag></asp:Label>).*?</asp:GridView>)|(?<wanted>(?<openingtag><asp:Label.*?>)(?<content>.*?)(?<closingtag></asp:Label>))

Use the named capture group wanted to find the labels you are looking for.

Discussion

An xml parser would more suited in the current case. If you ever find other tags like GridView that bring unwanted labels, you can customize the pattern like this.

string[] unwantedTags = {"GridView", "MyOtherTag", "AnotherUnwantedTag"};<br>
string unwantedTagsPattern = "(?:" + String.Join("|",unwantedTags) + ")";
string pattern = "(?<unwanted><asp:" + unwantedTagsPattern + ".*?>.*?(?<openingtag><asp:Label.*?>)(?<content>.*?)(?<closingtag></asp:Label>).*?</asp:" + unwantedTagsPattern + ">)|(?<wanted>(?<openingtag><asp:Label.*?>)(?<content>.*?)(?<closingtag></asp:Label>))"

Upvotes: 1

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