所以我有问题...对我来说，在cellForRowAtIndexPath方法中使用dispatch_async代码对我来说太笨重和混乱。
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath {
static NSString *CellIdentifier = @"myCellID";
myCell * cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
// someData - an array of dictionary for the tableview datasource
NSURL * imageURL = [NSURL URLWithString:someData[indexPath.row][@"photoURL"]];
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
dispatch_async(queue, ^{
NSData *data = [NSData dataWithContentsOfURL:imageURL];
UIImage *image = [UIImage imageWithData:data];
dispatch_async(dispatch_get_main_queue(), ^{
cell.myImageView.image = image;
});
});
}
经过一番研究后，我对此的解决方案是：
-(void)loadAsyncImage:(NSIndexPath *)indexPath{
NSURL * imageURL = [NSURL URLWithString:someData[indexPath.row][@"photoURL"] ];
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
dispatch_async(queue, ^{
NSData *data = [NSData dataWithContentsOfURL:imageURL];
UIImage *myImage = [UIImage imageWithData:data];
dispatch_async(dispatch_get_main_queue(), ^{
// _myTableView a property link from the interface builder
myCell * cell = (id)[_myTableView cellForRowAtIndexPath:indexPath];
cell.myImageView.image = myImage;
});
});
}
然后在
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath {
static NSString *CellIdentifier = @"myCellID";
myCell * cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
[self loadAsyncImage: indexPath];
}
令我惊讶的是它有效并且更清洁......但......我不知道这是否是正确的方法。有没有更好的方法来解决这个问题？或者这样可以吗？