popViewController何時調用textFieldShouldReturn？

Question

我有一個簡單的UIViewController與UINavigationController。視圖控制器包含的所有內容都是單個UITextField。此視圖有兩個目的：

• 創建一個新項目。在這種情況下，UINavigationController中有「取消」和「保存」按鈕。
• 編輯現有項目的名稱。在這種情況下，左上角只有「返回」按鈕。

我想要的是iPhone鍵盤上的Return鍵來關閉UITextField。

這裏是我的textFieldShouldReturn代碼：

-(BOOL)textFieldShouldReturn:(UITextField *)textField { 
    if(self.navigationItem.rightBarButtonItem) { 
     //If we're creating a new item (there'd be a Save button in the top right) 
     [self saveItem]; //This method just saves the Core Data for this item. 
     [self.delegate addItemViewController:self didAddItem:item]; //This works fine; this method just tells the delegate to dismiss this view controller. 
    }else { 
     //If there's no button in the top-right corner, then we're editing an existing fridge. 
     [self saveItem]; //This method just saves the Core Data for this item. 
     [self.navigationController popViewControllerAnimated:YES]; //This is what doesn't work. 
    } 
    [textField resignFirstResponder]; 
    return YES; 
} 

Answer 1

好吧，我建議你UIButtons去作爲操作被依賴，你想在你地對其進行管理。

btnSave = [UIButton buttonWithType:UIButtonTypeCustom]; 
    btnSave.frame = CGRectMake(250, 6, 61, 30); 
    [btnSave setImage:[UIImage imageNamed:@"btn-save.png"] forState:UIControlStateNormal]; 
    btnSave.backgroundColor = [UIColor clearColor]; 
    [btnSave addTarget:self action:@selector(btnSave_clicked:) forControlEvents:UIControlEventTouchUpInside]; 
    [self.navigationController.navigationBar addSubview:btnSave]; 

    - (IBAction)btnSave_clicked:(id)sender 
    { 
     //If we're creating a new item (there'd be a Save button in the top right) 
     [self saveItem]; //This method just saves the Core Data for this item. 
     [self.delegate addItemViewController:self didAddItem:item]; //This works fine; this method just tells the delegate to dismiss this view controller. 
    }