objective-c - NSTextField becomeFirstResponder 在 awakeFromNib 中不起作用

Question

我想在表单加载时设置焦点，但它在 awakeFromNib 中不起作用。

[myTextField becomeFirstResponder];

Answer 1

只是引用苹果文档：

Use the NSWindow makeFirstResponder: method, not this method, to make an object the first responder. Never invoke this method directly.

改为这样做：

[[myTextField window] makeFirstResponder:myTextField];

Answer 2

这个问题的 Swift 版本：

textField.window?.makeFirstResponder(textField)

Answer 3

- (BOOL) becomeFirstResponder
 {
 if (someCondition)
 {
     return NO;
 }

 BOOL retVal = [super becomeFirstResponder];

 // do your stuff
 return retVal;
}