About non-escaping, escaping closure and optional closure.

What is escaping meaning.

Use Objective-C class in Swift project.

Bridging objective-c to swift.

Use Swift class in Objective-C project.

Bridging Swift to Objective-c.

Basic behavior for between reusableView and contentView.

ContentView in UICollectionView and UITableView.

Show keyboard with "done" toolbar.

add toolBar, if view is UITextView and UITextField.