how to call function inside ascx files and give value to textbox.text

 Hi,
I need help. I would like to read text file inside my listview contril. I saved text file address to my database. Now my problem is I want to read thoese text file via text file address inside my ListView Control in ASCX file. So I need to call my ReadTxt function in my ASCX file.
<asp:textbox id="MyText" runat="server" text=' call my ReadTxt(text_address)  '/>
Please help me, I tried my best, But I faild. I don't know how to do it.  So I need help please.................

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