1浪箭、添加方法
[_phoneField addTarget:self action:@selector(textFieldDidChange:) forControlEvents:UIControlEventEditingChanged];
2穗椅、//監(jiān)聽輸入框
- (void)textFieldDidChange:(UITextField *)theTextField{
NSLog( @" %@", theTextField.text);
NSLog( @"輸入文本長度: %ld", theTextField.text.length);
}