It don't need complicated as you say. First, i want a textbox on Form1 to always display the same text as a textbox on Form2 when i press a letter key. Second, i have a project about File Explore in Windows, when i want to rename a folder or a file(i have used ListView to show file and folder), i must be add a form named Rename. And i'm stuck here, i can rename file, but can't update file's name in ListView or TreeView.