NSTextField作为FirstResponder没有stringValue，除非手动点击其他地方。

I have a NSView that when opened, the third NSTextField on it becomes FirstResponder to set the cursor there. If I open this form and start typing then click a save button then the NSTextField.stringValue in code is empty, even though it contains characters on the view. If I click off the field just before clicking the save button then the field stringValue is available in code. I have a NSView that when opened, the third NST