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directory info get files show directories C# .Net
There is sometimes a misunderstanding between a “file” and a “folder” in filesystems. In C# .Net the following is often used to list all “files” in a folder.
DirectoryInfo di = new DirectoryInfo("yourpath");
foreach (FileInfo fi in di.GetFiles()) {
//do work
}
However, even though you can specify to search containing subdirectories, the above function will not inherently list folders. If you are looking for the equivalent to “dir” or “ls”, instead use “GetFileSystemInfos()”.
DirectoryInfo di = new DirectoryInfo("yourpath");
//note the difference here with getfilesysteminfos
foreach (dynamic d in di.GetFileSystemInfos()) {
}
Note the usage of dynamic in the above example compared to the first example. This avoids any potential issues with inheritance and choosing the right class for your temp iterator variable for unboxing etc.
call parent page from user control to invoke page methods
To illustrate how we will accomplish this using Reflections, we will be using repeater in a user control within a page.
Your repeater loads data easily within the user control code behind, but you want to utilize the “ItemCommand” event of the repeater to update some values on the page page.
Here’s how this can work:
Parent Page:
//the name doesn't have to match the corresponding method on user control but makes code more readable
public void rptRepeaterName_ItemCommand(object sender, RepeaterCommandEventArgs e)
{
try
{
if (e.CommandName == "commandname")
{
//do some work on data then call update on parent page to reload data and show within a modal
ParentPage_UpdatePanel.Update();
ParentPage_ModalPopup.Show();
}
}
catch (Exception ex)
{
//do something
throw new ApplicationException(ex.ToString());
}
}
User Control:
protected void rptRepeaterName_ItemCommand(object sender, RepeaterCommandEventArgs e)
{
MethodInfo mi = this.Page.GetType().GetMethod("rptRepeaterName_ItemCommand", BindingFlags.Public | BindingFlags.Instance);
//note we specify parent page as the object and pass in a new object representing our repeater and carrying its parameters
if (mi!=null) mi.Invoke(this.Page, new Object[] {sender,e });
}
Voila! Behold the power of Reflections! 8)
In particular, one of the references below (thanks Bruce Barker!) helped me come to this answer, however, the exact code he presents will result in a “Non-static method requires a target” error.
To avoid this error, make sure you always pass in the object when invoking a method that is non-static (within a class that is instantiated).
To learn more about reflections and how it works search my blog for other examples, and visit MSDN for a good overview.
References
Velocity Reviews, http://www.velocityreviews.com/forums/t71075-invoke-methods-on-the-parent-page-from-the-user-control.html
Reflection Overview (MSDN), http://msdn.microsoft.com/en-us/library/f7ykdhsy%28v=vs.71%29.aspx
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