Introduction 
 
In Windows 10 we have OpenFileDialog which opens a dialog to pick the files. Here we are going to pick the text file in Windows 10.
Create a new Windows 10 project and create a button and image control to perform File Picker operation.
 
Firstly, create a new instance for FileOpenPicker as in the following code snippet:
- FileOpenPicker openPicker = new FileOpenPicker();       
 
Next, we have to set file picker ViewMode, you could ignore this, but if you would like to add, there are two options, such as List and Thumbnail. Here I will set thumbnail.
- openPicker.ViewMode = PickerViewMode.Thumbnail;    
 
Then set the suggested location as you wish. I am going to set the default location as a document library.
- openPicker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;     
 
We need to add FileTypeFilter; it is a mandatory field that you should add. It requires at least one type.
 
The FileTypeFilter is a read-only collection. We would be able to add values.
Here I am setting filter type for .txt files.
- openPicker.FileTypeFilter.Add(".txt");     
 
Finally, we are going to show the file picker dialog as in the following code snippet and we have the option to select single or multiple file selection.
- StorageFile file = await openPicker.PickSingleFileAsync();     
 
Finally, we are going to read the selected file using a stream and assign it to the text block.
- var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);    
 - using (StreamReader reader = new StreamReader(stream.AsStream()))    
 - {    
 -    textBlockShow.Text = reader.ReadToEnd();    
 - }    
 
The whole code looks like the following code:
- private async void buttonPick_Click(object sender, RoutedEventArgs e)    
 - {    
 -     FileOpenPicker openPicker = new FileOpenPicker();    
 -     openPicker.ViewMode = PickerViewMode.Thumbnail;    
 -     openPicker.SuggestedStartLocation = PickerLocationId.DocumentsLibrary;    
 -     openPicker.FileTypeFilter.Add(".txt");    
 -     StorageFile file = await openPicker.PickSingleFileAsync();    
 -     if(file != null)    
 -     {    
 -         var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read);    
 -         using(StreamReader reader = new StreamReader(stream.AsStream()))    
 -         {    
 -             textBlockShow.Text = reader.ReadToEnd();    
 -         }    
 -     }    
 -     else    
 -     {}    
 - }     
 
Now run, debug and run the app and here is the following output,
 
 
 
Summary
 
In this article, we learned about how to pick the text files in Windows 10.