1、创建UIAlertController
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"新建" message:@"" preferredStyle:UIAlertControllerStyleAlert];
2、添加一个输入框 添加输入框文字改变监听
[alertController addTextFieldWithConfigurationHandler:^(UITextField *textField){
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(alertTextFieldDidChange:) name:UITextFieldTextDidChangeNotification object:textField];
textField.placeholder = @"请输入全称";
}];
3、在确定和取消按钮事件中相应的移除监听
UIAlertAction *cancleAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
[[NSNotificationCenter defaultCenter] removeObserver:self name:UITextFieldTextDidChangeNotification object:nil];
}];
UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"确认" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
UITextField * wordNameTextField = alertController.textFields.firstObject;//获取到textField
[[NSNotificationCenter defaultCenter] removeObserver:self name:UITextFieldTextDidChangeNotification object:nil];
}];
okAction.enabled = NO;//此处确定按钮在输入框内没有内容时置灰不可用
[alertController addAction:cancleAction];
[alertController addAction:okAction];
[self presentViewController:alertController animated:YES completion:nil];
4、实现监听方法
- (void)alertTextFieldDidChange:(NSNotification *)notification{
UIAlertController *alertController = (UIAlertController *)self.presentedViewController;
if (alertController) {
UITextField *wordNameTextField = alertController.textFields.firstObject;
UIAlertAction *okAction = alertController.actions.lastObject;
okAction.enabled = ![@"" isEqualToString:wordNameTextField.text];//输入框有内容时可用
}
}