The type or namespace name 'Forms' does not exist in the namespace 'System.Windows'

Question

I need to select json file.

public void LoadChartData()
{
   var ofDialog = new System.Windows.Forms.OpenFileDialog { Filter = @"json (*.json)|*.json" };
   if (ofDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
   { }
}

Unfortunately compilation of this code returns error (twice, for each System.Windows.Forms ):

Error   CS0234  The type or namespace name 'Forms' does not exist in the namespace 'System.Windows' (are you missing an assembly reference?)    

How to handle with this error?

Answer 1

Include the System.Windows.Forms assembly in your project (as the error message suggested).

Go to your Solution Explorer, right click your project. Then click Add Reference. Choose System.Windows.Forms and hit OK.