我有一个名为 ProductiPadCell 的自定义单元格类,专为 iPad 设计。 (iOS 5 SDK)
我想要实现的是根据当前状态(扩展与否)和界面方向加载我的自定义单元格。我在 View Controller 中处理这两种情况,问题是我不喜欢它的性能。我NOT为下面定义的任何xibs定义了一个cellIdentifier,最近我检测到我的tableView 的cellForRowAtIndexPath:
ProductiPadCell 有 4 个不同的 XIB;
ProductiPadCell-Regular.xib
ProductiPadCell-Regular-Landscape.xib
ProductiPadCell-Expanded.xib
ProductiPadCell-Expanded-Landscape.xib
ProductiPadCell 定义;
@interface ProductiPadCell : UITableViewCell
@property (weak, nonatomic) IBOutlet UIButton *detailButton;
@property (weak, nonatomic) IBOutlet UILabel *productDescriptionLabel;
@property (weak, nonatomic) IBOutlet TTTAttributedLabel *timeLabel;
@property (weak, nonatomic) IBOutlet TTTAttributedLabel *def1Label;
@property (weak, nonatomic) IBOutlet TTTAttributedLabel *def2Label;
@property (weak, nonatomic) IBOutlet UIImageView *thumbnail;
// appears in case the cell is expanded
@property (weak, nonatomic) IBOutlet UIView *detailHolderView;
@property (weak, nonatomic) IBOutlet UILabel *detailLabel;
// calls a method at the superview's ViewController
- (void)presentDetailViewWithIndexNSInteger)index;
@end
TableView 的 cellForForAtIndexPath
- (UITableViewCell *)tableViewUITableView *)tableView cellForRowAtIndexPathNSIndexPath *)indexPath
{
// table identifier does not matches the xib's cell identifier
// cell identifier of all 4 xibs are "" (empty)
static NSString *simpleTableIdentifier = @"Cell";
BOOL isExpanded = [[[targetDictionary objectForKey"isItemExpanded"] objectAtIndex:indexPath.row] boolValue];
ProductiPadCell *cell = (ProductiPadCell *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil)
{
// Load the required nib for the current orientation and detail selection style
if (deviceOrientation == UIDeviceOrientationPortrait) {
if (isExpanded) {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed"roductiPadCell-Regular-Expanded" owner:self options:nil];
cell = [nib objectAtIndex:0];
// additional settings for expanded case
}
else {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed"roductiPadCell-Regular" owner:self options:nil];
cell = [nib objectAtIndex:0];
// additional settings for NOT expanded case
}
}
else {
if (isExpanded) {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed"roductiPadCell-Landscape-Expanded" owner:self options:nil];
cell = [nib objectAtIndex:0];
}
else {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed"roductiPadCell-Regular-Landscape" owner:self options:nil];
cell = [nib objectAtIndex:0];
}
}
}
// connect cell information with cell IBOutlets
cell.productDescriptionLabel.text = [[targetDictionary objectForKey"key"] objectAtIndex:indexPath.row];
// ....
[cell.thumbnail setImage:[UIImage imageNamed"thumb_image.jpg"]];
[cell.thumbnail.layer setCornerRadius:7.0f];
[cell.thumbnail.layer setBorderWidth:5.0f];
[cell.thumbnail.layer setBorderColor:[UIColor clearColor].CGColor];
[cell.thumbnail setClipsToBounds:YES];
if (isExpanded) {
cell.detailLabel.text = [[targetDictionary objectForKey"key"] objectAtIndex:indexPath.row];
}
return cell;
}
除了我目前的方法之外,我应该怎么做才能加载我的 xib?在每次更改方向和单击按钮时,我都会调用 [tableView reloadData] 并且由于 dequeueReusableCellWithIdentifier:simpleTableIdentifier 找不到 simpleTableIdentifier,它总是会创建新单元格。如果我将 simpleIdentifier 定义为我的单元格 xib,它们在大小写更改(方向更改、展开状态更改)期间不会更改。
小区标识符的最佳用途是什么?我是否应该使用 dequeueReusableCellWithIdentifier:simpleTableIdentifier 以外的其他方法
我正在等待针对当前情况的任何解决方案,因为我确信一遍又一遍地加载每个单元格并不是最有效的方法。
Best Answer-推荐答案 strong>
这是一种方式,缓存 Nib
合成这个属性
@property (nonatomic, strong) id cellNib;
@synthesize cellNib = _cellNib;
自定义getter
-(id)cellNib
{
if (!_cellNib)
{
Class cls = NSClassFromString(@"UINib");
if ([cls respondsToSelectorselector(nibWithNibName:bundle])
{
_cellNib = [[cls nibWithNibName"SomeCell" bundle:[NSBundle mainBundle]] retain];
}
}
return _cellNib;
}
在 viewDidLoad
[self.tableView registerNib:[UINib nibWithNibName:@"SomeCell" bundle:nil] forCellReuseIdentifier:kCellIdentification];
在 tableView:cellForRowAtIndexPath:
SomeCell *cell = [tableView dequeueReusableCellWithIdentifier:kCellIdentification];
if (cell == nil)
{
//If nib cache
if ([self cellNib]) {
NSArray* viewFromNib = [[self cellNib] instantiateWithOwner:self options:nil];
cell = (SomeCell *)[viewFromNib objectAtIndex:0];
}else { //nib not cache
NSArray *views = [[NSBundle mainBundle] loadNibNamed:@"SomeCell" owner:nil options:nil];
cell = (SomeCell *)[views objectAtIndex:0];
}
}
希望有帮助
关于ios - UITableViewCell 为不同的方向和单元格类型加载自定义 XIB,我们在Stack Overflow上找到一个类似的问题:
https://stackoverflow.com/questions/14960216/
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