Ios 如何在我的应用程序中为缓存图像集成网络?
我正在使用带有自定义单元格的表视图。我想在缓存中存储图像。Ios 如何在我的应用程序中为缓存图像集成网络?,ios,objective-c,uitableview,caching,afnetworking,Ios,Objective C,Uitableview,Caching,Afnetworking,我正在使用带有自定义单元格的表视图。我想在缓存中存储图像。 这是我的代码: 我的表视图委托方法: - (UITableViewCell*)tableView:(UITableView*)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath { LiveCameraCell* cell = ( LiveCameraCell* )[self.tableView dequeueReusableCellWithIdentifier:@"
这是我的代码:
我的表视图委托方法:
- (UITableViewCell*)tableView:(UITableView*)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath {
LiveCameraCell* cell = ( LiveCameraCell* )[self.tableView dequeueReusableCellWithIdentifier:@"livecameracell"];
if (cell == nil) {
NSLog(@"Error dequeuing prototype cell");
}else{
cell.cameraData = [self getCamera:tableView forRowAtIndexPath:indexPath];
}
return cell;
}
- (CameraData*) getCamera:(UITableView*)tableView forRowAtIndexPath:(NSIndexPath*) indexPath {
CameraData* cameraData = nil;
if (tableView == self.searchDisplayController.searchResultsTableView) {
cameraData = (CameraData*) [searchResultsCameras objectAtIndex:indexPath.row];
} else {
cameraData = (CameraData*) [allCameras objectAtIndex:indexPath.row];
}
return cameraData;
}
-(void)tableView:(UITableView*)tableView willDisplayCell:(UITableViewCell*)cell forRowAtIndexPath:(NSIndexPath*)indexPath {
LiveCameraCell* liveCameraCell = (LiveCameraCell*)cell;
CameraData* cameraData = [self getCamera:tableView forRowAtIndexPath:indexPath];
liveCameraCell.mapButton.hidden = [cameraData hasGeoLocation] ? NO : YES;
if (![cameraData isSnapshotLoaded] && ![cameraData isLoadingImage]) {
/*[cameraData loadImageAsync1:^{
liveCameraCell.cameraImage.image = cameraData.snapshotImage;
[cell setNeedsLayout];
[cell setNeedsDisplay];
}];*/
[cameraData loadImageAsync1:^(UIImage* image) {
dispatch_async(dispatch_get_main_queue(), ^{
//NSLog(@"Image load");
if (![cameraData isThumbnailCachedWithHeight:[self thumbnailHeight] width:[self thumbnailWidth]])
{
if(cameraData.name == cameraData.name)
{
NSLog(@"Image load");
[liveCameraCell showThumbnail:cameraData.snapshotImage];
//liveCameraCell.cameraImage.image = cameraData.snapshotImage;
}
}
[cell setNeedsLayout];
[cell setNeedsDisplay];
});
}];
}
else
{
if (![cameraData isThumbnailCachedWithHeight:[self thumbnailHeight] width:[self thumbnailWidth]])
{
if (cameraData.snapshotImage !=liveCameraCell.cameraImage.image) {
liveCameraCell.cameraImage.image = cameraData.snapshotImage;
}
}
/*[cameraData downloadThumbnailWithHeight:[self thumbnailHeight] width:[self thumbnailWidth] callback:^(UIImage* thumbnail) {
dispatch_async(dispatch_get_main_queue(), ^{
[liveCameraCell showThumbnail:thumbnail];
});
}];*/
}
liveCameraCell.label.text = cameraData.name;
liveCameraCell.description.text = cameraData.description;
[cell setNeedsLayout];
[cell setNeedsDisplay];
}
所有工作都在我的willDisplayCell:
方法中完成。这是我的另一个方法,在
willDisplayCell:
中使用:
-(void)loadImageAsync1:(void (^)(UIImage*))callback {
if (_snapshotImage) { callback(_snapshotImage); return; }
_loadingImage = YES;
HttpRequest* request = [HttpRequest requestWithRelativePath:[NSString stringWithFormat:@"/api/v1/camera/%@/snapshot?width=64", _uuid]];
[HttpResponse processAsynchronousRequest:request onCompletion:^(HttpResponse* response){
_snapshotImage = [UIImage imageWithData:response.responseData];
_loadingImage = NO;
if (!_snapshotImage) _snapshotImage = [UIImage imageNamed:@"gray_thumbnail_background.png"];
callback(_snapshotImage);
}];
}
请帮助集成此库。我已经在我的项目中添加了类。现在,下一步怎么办?
如何在
willDisplayCell:
中添加此项
提前感谢。根据单元格数量将所有url存储在一个数组中 然后在willDisplayCell方法中就是这样做的
-(void)tableView:(UITableView*)tableView willDisplayCell:(UITableViewCell*)cell forRowAtIndexPath:(NSIndexPath*)indexPath {
[youCellImageView setImagewithUrl:[arrayUrl objectAtIndex:indexPath.row] placeholderImage:"placeHOlderImage"];
}
您可以使用SDWebImage库,并使用以下方法下载图像
[cell.imgProductImage setImageWithURL:[NSURL URLWithString:[[self.arrProduct objectAtIndex:indexPath.item] valueForKey:@"variant_image"]] placeholderImage:[UIImage imageNamed:@"Placeholder.png"]];
使用afnetworkings afnetworking+uiimageView类,该类提供了从url获取图像并将其缓存在内存中的直接方法。。。这样地。。[imageView setImageforUrl:url占位符图像:yourimage];是的,我知道。但如何在我的willDisplayCell中使用它?因为我已经尝试过了。不,我没有使用数据库。所以请告诉我如何在我的willDisplayCell方法中使用这个?目前只有一个问题,第一次滚动后图像会发生变化。是否有任何解决方案,缓存正在工作,但主要问题是在滚动时更改图像?