Question

此应用是带有标签栏控制器的表格视图。我正在记录数组的计数：arrayOfFavourites，即使我添加一个对象继续有一个nil值，我的相关代码，显示的所有对象都在代码中分配和初始化（之前或现在）有些是实例，有些是属性：

ListViewController.m：

  -(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

NSLog(@"TOUCHED CELL!");

// Push the web view controller onto the navigation stack - this implicitly 
// creates the web view controller's view the first time through
[[self navigationController] pushViewController:webViewController animated:YES];

// Grab the selected item
entry = [[channel items] objectAtIndex:[indexPath row]];

if (!entry) {
    NSLog(@"!entry");
}

// Construct a URL with the link string of the item
NSURL *url = [NSURL URLWithString:[entry link]];

// Construct a request object with that URL
NSURLRequest *req = [NSURLRequest requestWithURL:url];

  // Load the request into the web view 
[[webViewController webView] loadRequest:req];

// Take the cell we pressed
// IMPORTANT PART
CELL = [tableView cellForRowAtIndexPath:indexPath];

[webViewController setItem:entry];

webViewController = nil;
webViewController = [[WebViewController alloc] init];
[entry release];

  }

WebViewController.m：

你摇动到最喜欢的细胞

 -(void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event {

cellToPassOn = nil;

NSLog(@"Favouriting"); // YES I KNOW SPELLING

// This is pretty simple, what we do is we take the cell we touched and take its title and link 
// then put it inside an array in the Favourites class

Favourites *fav = [[Favourites alloc] init];
ListViewController *list = [[ListViewController alloc] init];
[self setCellToPassOn: [list CELL]];

if (!item) {
    NSLog(@"NILLED ITEM");

}

[[fav arrayOfFavourites] addObject:[item autorelease]];
[fav setCell: cellToPassOn];
[fav release];
[list release];
item = nil;

 }

Favourites.m：

 -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
  {

arrayOfFavourites = [[NSMutableArray alloc] init];


NSLog(@"ROWS NO.");
NSLog(@"%i", [arrayOfFavourites count]);

return [arrayOfFavourites count];
}

Answer 1

为什么要在tableview:numberOfRowsInSection中初始化数组？这将导致每次重新加载表视图时重置阵列。这可能是你的问题。

Answer 2

您要在-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

中分配数组

尝试将其分配到其他地方。

Answer 3

您可以在arrayOfFavorites中分配tableView:numberOfRowsInSectionMethod，但首先需要检查它是否为零。

if( !arrayOfFavorites )
    arrayOfFavoriges = [[NSMutableArray alloc] init];

您应该在dealloc方法中释放它：[arrayOfFavorites release]。

Answer 4

 -(void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event {
 cellToPassOn = nil;
 NSLog(@"Favouriting"); // YES I KNOW SPELLING
 // HERE creation of a Brand NEW empty Favourites instance
 Favourites *fav = [[Favourites alloc] init];
 // HERE creation of a Brand NEW empty ListViewController instance
 ListViewController *list = [[ListViewController alloc] init];
 // HERE we hope that the ListViewController as CELL other then nil when it is Brand NEW
 [self setCellToPassOn: [list CELL]];

 if (!item) {
     NSLog(@"NILLED ITEM");
 }

 [[fav arrayOfFavourites] addObject:[item autorelease]];
 [fav setCell: cellToPassOn];
 [fav release];
 // HERE the fav instance get deallocated and don't exist anymore
 [list release];
 // HERE the list instance get deallocated and don't exist anymore
 item = nil;
 }

在此代码中list和fav只存在于此方法的正文中，尝试获取他们执行的值将失败，因为list和{{1在该方法之外不存在。

addObject：to array not working（array仍为nil）

4 个答案: