我有一个 UITableViewController，它有一个带有自定义单元格的表格视图（它们有一个子类和一个 xib）。问题是我从博客加载数据并且显示正常，但是当我尝试滚动或触摸时，单元格会重置，就像它们没有加载一样。
这是它的外观：
这就是我尝试滚动时发生的情况：
这是我的视图控制器代码：
#import "TLDRCategoryViewController.h"
@interface TLDRCategoryViewController ()
@property(nonatomic,strong) IBOutlet UIView *headerView;
@property(nonatomic,strong) NSMutableArray *posts;
@property(nonatomic, assign, readonly) TLDRTag category;
@property(nonatomic, strong) IBOutlet UILabel *category_label;
@end
@implementation TLDRCategoryViewController
@synthesize headerView = _headerView, posts = _posts, category = _category, category_label = _category_label;
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
-(void)setCategory:(TLDRTag)_cat {
_category = _cat;
}
- (void)viewDidLoad
{
[super viewDidLoad];
self.tableView.tableHeaderView = _headerView;
_category_label.text = [TLDRHelper showableNameForTag:_category];
_category_label.textColor = [TLDRHelper colorForTag:_category];
TLDRRetriever *retriever = [[TLDRRetriever alloc] initWithDelegate:self];
[retriever postsByCategory:_category];
if (_posts == nil)
_posts = [[NSMutableArray alloc] init];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)postsLoaded:(NSDictionary *)postsDict {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, (unsigned long)NULL), ^(void) {
for (NSDictionary *key in postsDict[@"response"][@"posts"]) {
TLDRNewsItem *newsPost = [[TLDRNewsItem alloc] initWithDictionary:key];
[self.posts addObject:newsPost];
}
dispatch_sync(dispatch_get_main_queue(), ^{
[self.tableView reloadData];
});
});
}
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// Return the number of sections.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [self.posts count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"TLDRNewsCell";
TLDRNewsCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil){
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"TLDRNewsCell" owner:nil options:nil];
for(id currentObject in topLevelObjects) {
if([currentObject isKindOfClass:[TLDRNewsCell class]]) {
cell = (TLDRNewsCell *)currentObject;
break;
}
}
}
cell.title.text = ((TLDRNewsItem*)self.posts[indexPath.row]).articleTitle;
cell.content.text = ((TLDRNewsItem*)self.posts[indexPath.row]).articleTLDR;
return cell;
}
-(float)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *text = ((TLDRNewsItem*)self.posts[indexPath.row]).articleTLDR;
CGSize textSize = [text sizeWithFont:[UIFont systemFontOfSize:14.0f] constrainedToSize:CGSizeMake(self.tableView.frame.size.width - PADDING * 3, 1000.0f)];
return textSize.height + PADDING * 3;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Navigation logic may go here. Create and push another view controller.
/*
<#DetailViewController#> *detailViewController = [[<#DetailViewController#> alloc] initWithNibName:@"<#Nib name#>" bundle:nil];
// ...
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
*/
}
这是 TLDRRetriever 的相关部分：
-(void)postsByCategory:(NSInteger)cat {
NSString *string_cat = @"";
switch (cat) {
case TLDRTagWorldNews:
string_cat = @"world%20news";
break;
case TLDRTagBusiness:
string_cat = @"business";
break;
case TLDRTagDesign:
string_cat = @"design";
break;
case TLDRTagEntertainment:
string_cat = @"entertainment";
break;
case TLDRTagFacts:
string_cat = @"facts";
break;
case TLDRTagHealth:
string_cat = @"health";
break;
case TLDRTagPolitics:
string_cat = @"politics";
break;
case TLDRTagScience:
string_cat = @"science";
break;
case TLDRTagSports:
string_cat = @"sports";
break;
case TLDRTagTech:
string_cat = @"tech";
break;
case TLDRTagWeb:
string_cat = @"web";
break;
default:
string_cat = @"";
break;
}
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_async(queue, ^{
NSData* data = [NSData dataWithContentsOfURL:[NSURL URLWithString:[NSString stringWithFormat:@"%@%@", kTLDRAPIURLCats, string_cat]]];
NSError *error;
NSDictionary* json = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];
[[self delegate] postsLoaded:json];
});
}
我在该应用程序上也有一个几乎完全相同的视图控制器，它工作正常（我正在使用该控制器的大部分代码，这个控制器可以重复用于其他类似类别）。这个控制器是批量分配的（我分配了 11 个这个控制器并将它们保存在一个数组中）。我无法调试这个，所以我不知道发生了什么。代码有问题吗？谢谢！