using使用后释放资源.txt

c#的知识类库

try
			{
				using(StreamReader reader=File.OpenText(fileName))
			{
				textBoxEdit.Clear();
				textBoxEdit.Text=reader.ReadToEnd();
			}
			}
			catch(IOException ex)
			{
			MessageBox.Show(ex.Message,"Simple Editor",MessageBoxButtons.OK,MessageBoxIcon.Exclamation);				
			}