需要对图片进行缓存 写入沙盒中，使用多线程下载图将队列放到字典中，value 线程 key 下载路径 判断是否有该key 没有创建添加一个线程下载
赋值图片只需刷新对应cell 就可以
@property(nonatomic,strong)NSMutableDictionary * imageCache;
@property(nonatomic,strong)NSMutableDictionary * operations;
@property(nonatomic,strong)NSOperationQueue * queue;
-(NSOperationQueue *)queue
{
if (!_queue) {
_queue=[[NSOperationQueue alloc]init];
}
return _queue;
}
-(NSMutableDictionary *)operations
{
if (!_operations) {
_operations=[NSMutableDictionary dictionary];
}
return _operations;
}
-(NSMutableDictionary *)imageCache{
if (!_imageCache) {
_imageCache=[NSMutableDictionary dictionary];
}
return _imageCache;
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
// CarTableViewCell *cell=[[CarTableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"int"];
static NSString* [email protected]"app";
CarTableViewCell * cell=[tableView dequeueReusableCellWithIdentifier:ID];
if (!cell) {
cell=[[CarTableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ID];
}
if (allDataArray.count>0) {
NSDictionary * unit=[allDataArray objectAtIndex:indexPath.row];
cell.titleName.text=[NSString stringWithFormat:@"%@ %@",[unit objectForKey:@"carcName"],[unit objectForKey:@"carkName"]];
cell.timeAndDistance.text=[NSString stringWithFormat:@"%@/%@公里数",[unit objectForKey:@"inspectionDate"],[unit objectForKey:@"mileage"]];
cell.money.text=[NSString stringWithFormat:@"%@万",[unit objectForKey:@"price"]];
NSString *imagearr=[unit objectForKey:@"img"];
NSArray * arr=[imagearr componentsSeparatedByString:@";"];
NSString * path=[NSString stringWithFormat:@"http://121.201.18.34:8080/CAR/upload/car/%@",arr[0]];
UIImage * image=self.imageCache[path];
if (image) {
cell.CarImageView.image=image;
}else {
NSString * cachesPath=[NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject];
NSString * filename=[path lastPathComponent];
//计算文件的全路径
NSString * file =[cachesPath stringByAppendingPathComponent:filename];
//加载沙盒的文件数据
NSData * data=[NSData dataWithContentsOfFile:file];
NSLog(@"%@",file);
if (data) {
UIImage * image=[UIImage imageWithData:data];
cell.CarImageView.image=image;
}else{
NSOperation * operation = self.operations[path];
if (operation==nil) {
operation=[NSBlockOperation blockOperationWithBlock:^{
//下载图片
NSData * data=[NSData dataWithContentsOfURL:[NSURL URLWithString:path]];
//数据加载失败
if (data==nil) {
//移除操作
[self.operations removeObjectForKey:path];
return ;
}
UIImage * image=[UIImage imageWithData:data];
//回到主线程显示图片
[[NSOperationQueue mainQueue]addOperationWithBlock:^{
[tableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationNone];
}];
//存放到字典中
self.imageCache[path]=image;
//将图片写到沙盒中
[data writeToFile:file atomically:YES];
}];
self.operations[path]=operation;
[self.queue addOperation:operation];
}
}
}
// [cell.CarImageView sd_setImageWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://121.201.18.34:8080/CAR/upload/car/%@",arr[0]]]];
}
return cell;
}