Ios 在UITableViewCell中显示MKMapView而不减慢UI

我试图在一些UiTableViewCell中放置一个MKMapView，但是（在iPhone 5上，甚至在其他设备上），当应用程序加载带有地图的单元格时，滚动变得不太平滑

有什么方法，用GCD或者别的什么，可以更好地做到这一点吗

以下是结果的屏幕截图：

我从Nib加载单元格，下面是设置坐标和注释的代码（使用自定义视图，但这不是问题所在）

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我最终使用MKMapSnapshotter来支持这个强大而快速的功能，并对运行iOS6的设备使用googlestaticmapsapi。我认为这是我能得到的最好、最快的解决方案

谢谢你的建议

if ( IS_IOS7 ) {

    // Placeholder
    cell.objectImage.image = [UIImage imageNamed:@"mapPlaceholder"];

    // Cooridinate
    MKCoordinateRegion region;
    region.center = activity.object.location.coordinate;
    MKCoordinateSpan span;
    span.latitudeDelta = 0.055;
    span.longitudeDelta = 0.055;
    region.span = span;
    [self.mapViewForScreenshot setRegion:region animated:NO];

    MKMapSnapshotOptions *options = [[MKMapSnapshotOptions alloc] init];
    options.region = self.mapViewForScreenshot.region;
    options.scale = [UIScreen mainScreen].scale;
    options.size = CGSizeMake(300, 168);

    MKMapSnapshotter *snapshotter = [[MKMapSnapshotter alloc] initWithOptions:options];
    [snapshotter startWithCompletionHandler:^(MKMapSnapshot *snapshot, NSError *error) {

        UIImage *image = snapshot.image;
        [cell.objectImage setImage:image];
        cell.mapPinImageView.hidden = NO;

    }];

}else{

    cell.mapPinImageView.hidden = NO;
    [cell.objectImage setImageWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/staticmap?center=%f,%f&zoom=14&size=600x338&maptype=roadmap&sensor=false&key=APIKEY",activity.object.location.coordinate.latitude, activity.object.location.coordinate.longitude]] placeholderImage:nil];

}

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根据您的回答，您还可以在后台创建快照，并在主队列上执行结果（请不要忘记在更新单元格之前检查错误）：

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它需要实际的地图视图吗？出于性能原因，您通常希望拍摄地图快照并插入该图像，而不是实际的地图视图。iOS 7有一个专门为此设计的

MKMapSnapshotter

。或者你也需要支持早期版本吗？是的，我也需要支持iOS6。MKMapSnapshotter很酷，速度也很快。iOS6中也有类似的东西？当然没有什么比iOS7的

MKMapSnapshotter

更优雅的了。我见过一些手动尝试使用

mapViewDidFinishLoadingMap

和

renderInContext

，但它非常难看。

if ( IS_IOS7 ) {

    // Placeholder
    cell.objectImage.image = [UIImage imageNamed:@"mapPlaceholder"];

    // Cooridinate
    MKCoordinateRegion region;
    region.center = activity.object.location.coordinate;
    MKCoordinateSpan span;
    span.latitudeDelta = 0.055;
    span.longitudeDelta = 0.055;
    region.span = span;
    [self.mapViewForScreenshot setRegion:region animated:NO];

    MKMapSnapshotOptions *options = [[MKMapSnapshotOptions alloc] init];
    options.region = self.mapViewForScreenshot.region;
    options.scale = [UIScreen mainScreen].scale;
    options.size = CGSizeMake(300, 168);

    MKMapSnapshotter *snapshotter = [[MKMapSnapshotter alloc] initWithOptions:options];
    [snapshotter startWithCompletionHandler:^(MKMapSnapshot *snapshot, NSError *error) {

        UIImage *image = snapshot.image;
        [cell.objectImage setImage:image];
        cell.mapPinImageView.hidden = NO;

    }];

}else{

    cell.mapPinImageView.hidden = NO;
    [cell.objectImage setImageWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/staticmap?center=%f,%f&zoom=14&size=600x338&maptype=roadmap&sensor=false&key=APIKEY",activity.object.location.coordinate.latitude, activity.object.location.coordinate.longitude]] placeholderImage:nil];

}

if ( IS_IOS7 ) {

    cell.objectImage.image = [UIImage imageNamed:@"mapPlaceholder"];

    // Cooridinate
    MKCoordinateRegion region;
    region.center = activity.object.location.coordinate;
    MKCoordinateSpan span;
    span.latitudeDelta = 0.055;
    span.longitudeDelta = 0.055;
    region.span = span;
    [self.mapViewForScreenshot setRegion:region animated:NO];

    MKMapSnapshotOptions *options = [[MKMapSnapshotOptions alloc] init];
    options.region = self.mapViewForScreenshot.region;
    options.scale = [UIScreen mainScreen].scale;
    options.size = CGSizeMake(300, 168);

    MKMapSnapshotter *snapshotter = [[MKMapSnapshotter alloc] initWithOptions:options];

    dispatch_queue_t executeOnBackground = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

    [snapshotter startWithQueue:executeOnBackground completionHandler:^(MKMapSnapshot *snapshot, NSError *error) {

        dispatch_async(dispatch_get_main_queue(), ^{
                if (!error) {
                    cell.objectImage.image = snapshot.image;
                    cell.mapPinImageView.hidden = NO;
                } 
            });
        }];
    }];

} else {
    cell.mapPinImageView.hidden = NO;
    [cell.objectImage setImageWithURL:[NSURL URLWithString:@""] placeholderImage:nil];
}