在視圖控制器之間進行通信的最佳方式是什么？作為目標c、可可和iPhonedev的新手，我強烈希望充分利用語言和框架。我正在使用的資源之一是斯坦福大學的CS193P課程，這是他們在網絡上留下的。它包括課堂講稿、作業和示例代碼，而且由于這門課程是由Appledev提供的，所以我肯定認為它是“從馬嘴里來的”。班級網站：http：/www.stanford.edu/class/cs193p/cgi-bin/index.php第08課與構建一個基于UINavigationController的應用程序有關，該應用程序有多個UIViewController被推入UINavigationController堆棧。UINavigationController就是這樣工作的。這是合乎邏輯的。但是，幻燈片中有一些關于UIViewController之間通信的嚴厲警告。我要引用這一系列的幻燈片：http：/cs193p.stanford.edu/下載/08-NavigationTabBarControllers.pdf第16/51頁：如何不共享數據全局變量或單變量這包括你的申請委托直接依賴關系降低了代碼的可重用性。更難調試和測試好的。我受夠了。不要盲目地將用于在視圖控制器之間通信的所有方法拋到應用程序委托中，并在app委托方法中引用viewController實例。還不錯。再往前看，這張幻燈片告訴我們應做。第18/51頁：數據流的最佳實踐弄清楚一點兒沒錯需要傳達什么定義輸入參數用于視圖控制器為了恢復層次結構，使用松耦合為觀察者定義一個通用接口(如委托)這張幻燈片之后是一張看上去像是保持式幻燈片的幻燈片，講師隨后用UIImagePickerController的例子演示了最佳實踐。我希望錄影帶能提供！好吧那么.?？峙挛业膐bjc-fu沒那么強壯。我也有點困惑，最后一行在上面的報價。我一直在谷歌上搜索這方面的內容，我找到了一篇似乎不錯的文章，討論了各種觀察/通知技術的方法：http：/cocoawithlove.com/2008/06/5方法#5甚至指示委托為一種方法！除了.。對象一次只能設置一個委托。那么，當我有多個視圖控制器通信時，我該怎么辦呢？好吧，那是密謀團伙。我知道我可以很容易地在app委托中使用我的通信方法，通過引用我的appagent中的多個視圖控制器實例，但是我想做這樣的事情右（邊），正確的方式，道路。請回答以下問題，幫助我“做正確的事情”：當我試圖在UINavigationController堆棧上推送一個新的視圖控制器時，誰應該做這件事。哪一個類/文件在我的代碼中是正確的位置嗎？當我想影響我的UIViewController中的某個數據(一個IPAR的值)時，我在異類UIViewController，做這件事的“正確”方法是什么？假設我們一次只能在一個對象中設置一個委托，那么當講師說的時候，實現是什么樣子的呢？“為觀察員定義通用接口(如委托)”..如果可能的話，偽代碼示例在這里非常有用。
3 回答
慕哥9229398
TA貢獻1877條經驗 獲得超6個贊
第一
第二
第三
在視圖控制器中使用依賴項注入的示例
@implementation BookPickerViewController-(void) doSomething {
// I need to do something with the BookWarehouse so I'm going to look it up
// using the BookWarehouse class method (comparable to a global variable)
BookWarehouse *warehouse = [BookWarehouse getSingleton];
...}@implementation BookPickerViewController-(void) initWithWarehouse: (BookWarehouse*)warehouse {
// myBookWarehouse is an instance variable
myBookWarehouse = warehouse;
[myBookWarehouse retain];}-(void) doSomething {
// I need to do something with the BookWarehouse object which was
// injected for me
[myBookWarehouse listBooks];
...}@implementation BookPickerViewController-(void) initWithWarehouse: (BookWarehouse*)warehouse
andCheckoutController:(CheckoutController*)checkoutController
{
myBookWarehouse = warehouse;
myCheckoutController = checkoutController;}-(void) handleCheckout {
// We've collected the user's book picks in a "bookPicks" variable
[myCheckoutController handleCheckout: bookPicks];
...}@interface MyBookWarehouse : NSObject <BookWarehouse> { ... } @end@implementation MyBookWarehouse { ... }
@end@interface MyCheckoutController : NSObject <CheckoutController> { ... } @end@implementation MyCheckoutController { ... }
@end...-(void) applicationDidFinishLoading {
MyBookWarehouse *myWarehouse = [[MyBookWarehouse alloc]init];
MyCheckoutController *myCheckout = [[MyCheckoutController alloc]init];
BookPickerViewController *bookPicker = [[BookPickerViewController alloc]
initWithWarehouse:myWarehouse
andCheckoutController:myCheckout];
...
[window addSubview:[bookPicker view]];
[window makeKeyAndVisible];}-(void) testBookPickerController {
MockBookWarehouse *myWarehouse = [[MockBookWarehouse alloc]init];
MockCheckoutController *myCheckout = [[MockCheckoutController alloc]init];
BookPickerViewController *bookPicker = [[BookPickerViewController alloc] initWithWarehouse:myWarehouse andCheckoutController:myCheckout];
...
[bookPicker handleCheckout];
// Do stuff to verify that BookPickerViewController correctly called
// MockCheckoutController's handleCheckout: method and passed it a valid
// list of books
...}
慕尼黑的夜晚無繁華
TA貢獻1864條經驗 獲得超6個贊
@class Editor;@protocol EditorDelegate// called when you're finished. updated = YES for 'save' button, NO for 'cancel'- (void)editor:
(Editor*)editor finishedEditingModel:(id)model updated:(BOOL)updated; @end// this is an abstract class@interface Editor :
UIViewController {
id model;
id <EditorDelegate> delegate;}@property (retain) Model * model;@property (assign) id <EditorDelegate> delegate;...define
methods here...@end@interface AmountEditor : Editor...define interface here...@end@interface TextEditor : Editor...define
interface here...@end// TransactionController shows the transaction's details in a table view@interface TransactionController :
UITableViewController <EditorDelegate> {
AmountEditor * amountEditor;
TextEditor * textEditor;
Transaction * transaction;}...properties and methods here...@end- (void)viewDidLoad {
amountEditor.delegate = self;
textEditor.delegate = self;}- (void)editAmount {
amountEditor.model = self.transaction;
[self.navigationController pushViewController:amountEditor animated:YES];}- (void)editNote {
textEditor.model = self.transaction;
[self.navigationController pushViewController:textEditor animated:YES];}- (void)editor:(Editor*)editor finishedEditingModel:
(id)model updated:(BOOL)updated {
if(updated) {
[self.tableView reloadData];
}
[self.navigationController popViewControllerAnimated:YES];}
侃侃無極
TA貢獻2051條經驗 獲得超10個贊
- 3 回答
- 0 關注
- 477 瀏覽
添加回答
舉報
0/150
提交
取消