如何使用UITableViewController释放内存

I'm using Instruments to monitor memory usage. I notice that memory always increase and not release anymore on my UITableViewController. I don't understand why. Following I list my codes

我用仪器来监控内存的使用。我注意到在我的UITableViewController上内存总是增加而不再释放。我不明白为什么。下面我列出我的代码

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    int row =  [indexPath section];
    static NSString *CellIdentifier = @"ApplicationCell";
    BookCell *cell = (BookCell *)[tableViewdequeueReusableCellWithIdentifier:CellIdentifier];
    if(cell == nil) {
        [[NSBundle mainBundle] loadNibNamed:@"BookCell" owner:self options:nil];
        cell = bookCell;
        self.bookCell=nil;
    }   
    Book *book = [books objectAtIndex:row];
    cell.selectionStyle = UITableViewCellSelectionStyleNone;
    cell.bookNameLabel.text = book.author;  
    cell.bookPriceLabel.text = book.price;
    cell.accessoryType=UITableViewCellAccessoryDisclosureIndicator;
        return cell;
}

3 个解决方案

#1

Hie...

快走…

Just try it this way, i hope i would work

就这样试试，我希望我能工作

(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { int row = [indexPath section];

(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {int row = [indexPath section];

if(cell == nil) { [[NSBundle mainBundle] loadNibNamed:@"BookCell" owner:self options:nil]; cell = bookCell; self.bookCell=nil; }
Book *book = [books objectAtIndex:row]; cell.selectionStyle = UITableViewCellSelectionStyleNone; cell.bookNameLabel.text = book.author;
cell.bookPriceLabel.text = book.price; cell.accessoryType=UITableViewCellAccessoryDisclosureIndicator; return cell; }

如果(cell == nil) {[NSBundle mainBundle] loadNibNamed:@"BookCell" owner:self options:nil];细胞= bookCell;self.bookCell =零;图书= [books objectAtIndex:row];细胞。selectionStyle = UITableViewCellSelectionStyleNone;cell.bookNameLabel。文本= book.author;cell.bookPriceLabel。文本= book.price;cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;返回单元;}

#2

Answer #1:

回答1:

If you are referring to memory allocation and not leaking memory, here is a suggestion.

如果您指的是内存分配而不是泄漏内存，这里有一个建议。

Implement viewDidUnload to release parts of your viewcontroller that are no longer needed. Typically, you would re-instantate these objects in viewDidLoad (or loadView if you are not using xib files).

实现viewDidUnload来释放视图控制器中不再需要的部分。通常，您将在viewDidLoad中重新实例化这些对象(或者如果不使用xib文件，则使用loadView)。

You can visualize this by placing NSLog statements inside viewDidUnload and in iphone simulator and click "Hardware->Simulate Memory Warning", unless they already unloaded, most of your non-visible viewcontrollers will run the viewdidunload method.

您可以通过在viewDidUnload和iphone模拟器中放置NSLog语句并单击“硬件->模拟内存警告”来实现可视化，除非它们已经卸载，否则大多数不可见的viewcontroller会运行viewDidUnload方法。

Answer #2:

答案2:

If you are referring to memory leaks, then I would suspect the way you are loading table cells is leaking memory. Here is a good reference for loading tablecells from xibs. Your method might be correct, I'm just not familiar with it.

如果您指的是内存泄漏，那么我将怀疑您加载表单元格的方式是内存泄漏。这里有一个从xibs装载台布的很好的参考。你的方法可能是对的，只是我不熟悉而已。

#3

Your code looks leak-free to me.

我觉得你的代码没有漏洞。

I also noticed that the following line looks like it should be causing release of your custom cell object early (assuming the bookCell property is declared as "retain"):

我还注意到，以下一行看起来应该会使您的自定义单元格对象提前释放(假设bookCell属性被声明为“retain”):

self.bookCell=nil;

I would recommend removing it completely. You could also change it to (assuming the instance variable name matches the property name):

我建议把它完全移除。还可以将其更改为(假设实例变量名与属性名匹配):

bookCell=nil;

#1