How to put the following Object-C code into MonoMac code C#?

NSImage * pic = [[NSImage alloc] initWithContentsOfFile:@"/Users/Anne/Desktop/Sample.png"]; NSTextAttachmentCell *attachmentCell = [[NSTextAttachmentCell alloc] initImageCell:pic]; NSTextAttachment *attachment = [[NSTextAttachment alloc] init]; [attachment setAttachmentCell: attachmentCell ]; NSAttributedString *attributedString = [NSAttributedString attributedStringWithAttachment: attachment]; [[textView textStorage] appendAttributedString:attributedString];