How to delete a file using Application.dataPath ?

Questions & Answers
1

I have the following code in the Update() function:

		if(Input.GetKeyDown(KeyCode.F9))
		{
			File.Delete (Application.dataPath + "/Ob4.txt");
		}

I want to be able to delete the saved file whenever I press a button.
But whenever I press F9 the file still remains in the Assets folder.

2

You need to tab out of Unity then tab back in for the project folder to refresh. Or refresh the asset database in code:

// refresh editor view
#if UNITY_EDITOR
UnityEditor.AssetDatabase.Refresh();
#endif

Also, simply just check the file location with your file explorer to see if the file has been added/removed.

Edit : here is an example script. Create a new scene, attach script to an empty gameObject, and hit play. Editor project window refreshes when a file is created or deleted.

CreateAndDeleteFile.cs

using UnityEngine;
using System.Collections;
using System.IO;

public class CreateAndDeleteFile : MonoBehaviour 
{
	public string fileName = "ob04";
	public string fileExtension = ".txt";
	
	private string guiMessage = "type in a file name and hit save";
	
	
	void OnGUI() 
	{
		GUI.Box( new Rect( 160, 20, 400, 25 ), guiMessage );
		
		fileName = GUI.TextField( new Rect( 20, 20, 120, 25 ), fileName );
		
		if ( GUI.Button( new Rect ( 20, 60, 100, 30 ), "LOAD" ) )
		{
			LoadFile();
		}
		
		if ( GUI.Button( new Rect ( 20, 100, 100, 30 ), "SAVE" ) )
		{
			SaveFile();
		}
		
		if ( GUI.Button( new Rect ( 20, 140, 100, 30 ), "DELETE" ) )
		{
			DeleteFile();
		}
	}
	
	
	void LoadFile() 
	{
		string filePath = Application.dataPath + "/" + fileName + fileExtension;
		
		// check if file exists
		if ( !File.Exists( filePath ) )
		{
			guiMessage = "no " + fileName + " file exists"; //Debug.Log( "no " + fileName + " file exists" );
		}
		else
		{
			guiMessage = fileName + " file exists, reading..."; //Debug.Log( fileName + " file exists, reading ..." );
			
			// read file
			StreamReader readFile = new StreamReader( filePath );
			string readString = readFile.ReadToEnd(); //Debug.Log( readFile.ReadToEnd() );
			readFile.Close();
			
			guiMessage = guiMessage + " : " + readString;
		}
	}
	
	
	void SaveFile() 
	{
		string filePath = Application.dataPath + "/" + fileName + fileExtension;
		
		// check if file exists
		if ( !File.Exists( filePath ) )
		{
			guiMessage = "no " + fileName + " file exists, creating..."; //Debug.Log( "no " + fileName + " file exists, creating..." );
			
			// create new file
			StreamWriter newFile = new StreamWriter( filePath );
			newFile.WriteLine( "Hello, I am a text file :)" );
			newFile.Close();
			
			RefreshEditorProjectWindow();
		}
		else
		{
			guiMessage = fileName + " file already exists"; //Debug.Log( fileName + " file already exists" );
		}
	}
	
	
	void DeleteFile() 
	{
		string filePath = Application.dataPath + "/" + fileName + fileExtension;
		
		// check if file exists
		if ( !File.Exists( filePath ) )
		{
			guiMessage = "no " + fileName + " file exists"; //Debug.Log( "no " + fileName + " file exists" );
		}
		else
		{
			guiMessage = fileName + " file exists, deleting..."; //Debug.Log( fileName + " file exists, deleting..." );
			
			File.Delete( filePath );
			
			RefreshEditorProjectWindow();
		}
	}
	
	
	void RefreshEditorProjectWindow() 
	{
		#if UNITY_EDITOR
		UnityEditor.AssetDatabase.Refresh();
		#endif
	}
}