Picked some changes from 37c0b98, Try to dispose IDisposable objects more diligently

embroideryReader/frmMain.cs

@@ -244,6 +244,13 @@ namespace embroideryReader
                 tempImage = destImage;
             }
 
+            // About to abandon the current DrawArea object, dispose it now
+            if(DrawArea != null)
+            {
+                DrawArea.Dispose();
+                DrawArea = null;
+            }
+
             // Add transparency grid
             if (settings.transparencyGridEnabled)
             {
@@ -268,10 +275,15 @@ namespace embroideryReader
                     }
 
                     g.DrawImage(tempImage, 0, 0);
+
+                    // Done with tempImage
+                    tempImage.Dispose();
+                    tempImage = null;
                 }
             }
             else
             {
+                // Keeping the object tempImage was pointing at, so don't dispose it
                 DrawArea = tempImage;
             }
 
@@ -511,10 +523,12 @@ namespace embroideryReader
             {
                 float inchesPerMM = 0.03937007874015748031496062992126f;
                 e.Graphics.ScaleTransform((float)(e.PageSettings.PrinterResolution.X * inchesPerMM * 0.01f), (float)(e.PageSettings.PrinterResolution.Y * inchesPerMM * 0.01f));
-                Bitmap tempDrawArea = design.designToBitmap((float)settings.threadThickness, settings.filterStiches, settings.filterStitchesThreshold, e.PageSettings.PrinterResolution.X * inchesPerMM * 0.2f);
+                using (Bitmap tempDrawArea = design.designToBitmap((float)settings.threadThickness, settings.filterStiches, settings.filterStitchesThreshold, e.PageSettings.PrinterResolution.X * inchesPerMM * 0.2f))
+                {
                     e.Graphics.DrawImage(tempDrawArea, 30, 30);
                 }
             }
+        }
 
         private void printPreviewToolStripMenuItem_Click(object sender, EventArgs e)
         {
@@ -527,14 +541,17 @@ namespace embroideryReader
             if (DrawArea != null)
             {
                 Clipboard.Clear();
-                Bitmap temp = new Bitmap(DrawArea.Width, DrawArea.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
-                Graphics tempGraph = Graphics.FromImage(temp);
+                using (Bitmap temp = new Bitmap(DrawArea.Width, DrawArea.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb))
+                {
+                    using (Graphics tempGraph = Graphics.FromImage(temp))
+                    {
                         tempGraph.FillRectangle(Brushes.White, 0, 0, temp.Width, temp.Height);
                         tempGraph.DrawImageUnscaled(DrawArea, 0, 0);
-                tempGraph.Dispose();
+                    }
                     Clipboard.SetImage(temp);
                 }
             }
+        }
 
         private void refreshToolStripMenuItem_Click(object sender, EventArgs e)
         {
@@ -587,12 +604,13 @@ namespace embroideryReader
         {
             if (DrawArea != null)
             {
-                Bitmap temp = new Bitmap(DrawArea.Width, DrawArea.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
-
-                Graphics tempGraph = Graphics.FromImage(temp);
+                using (Bitmap temp = new Bitmap(DrawArea.Width, DrawArea.Height, System.Drawing.Imaging.PixelFormat.Format24bppRgb))
+                {
+                    using (Graphics tempGraph = Graphics.FromImage(temp))
+                    {
                         tempGraph.FillRectangle(Brushes.White, 0, 0, temp.Width, temp.Height);
                         tempGraph.DrawImageUnscaled(DrawArea, 0, 0);
-                tempGraph.Dispose();
+                    }
                     saveFileDialog1.FileName = "";
                     // "Bitmap (*.bmp)|*.bmp|PNG (*.png)|*.png|JPEG (*.jpg)|*.jpg|GIF (*.gif)|*.gif|TIFF (*.tif)|*.tif|All Files (*.*)|*.*"
                     saveFileDialog1.Filter = translation.GetTranslatedString(Translation.StringID.FILE_TYPE_BMP) + " (*.bmp)|*.bmp|" +
@@ -625,6 +643,7 @@ namespace embroideryReader
                     }
                 }
             }
+        }
 
         private void showStatus(string text, int msec)
         {