iOS GCD用于UITableView

我有一个非常密集的UITableView,需要进行一些优化.问题是,如何使用大中央站有效地做到这一点.每个单元格都有一个带有几个标签和两个图像的UIView.我已经将TableViewCell子类化了,并且视图正在被重用,尽管当表变大时它仍然有点滞后.我将如何使用GCD优化表格？或者有更好的方法吗？我在线程管理方面不是很强,并且正在寻找一些建议.

这是我的tableview的代码：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowATindexPath:(NSIndexPath *)indexPath
{

static NSString *CellIdentifier = @"Cell";
JointCAD *currentCall = [[xmlParser calls] objectATindex:indexPath.row];
self.tableView.BACkgroundColor = [UIColor colorWithPatternImage:[UIImage imagenamed:@"texture3.png"]];

TableViewCell *cell = (TableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil)
{
    cell = [[TableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reusEIDentifier:CellIdentifier];
}

cell.callTypeLabel.text = currentCall.currentCallType;
cell.LOCATIOnLabel.text = currentCall.LOCATIOn;
cell.unitsLabel.text = currentCall.units;
cell.stationLabel.text = [@"Station: " StringByAppendingString:currentCall.station];
cell.SELEctedBACkgroundView = cell.SELEctionView;

if ([currentCall.callType isEqualToString:@"F"]) {
    cell.imageType = Fire;
}
else {
    cell.imageType = EMS;
}

if ([currentCall.county isEqualToString:@"W"]) {
    cell.imageType1 = Washington;
}
else {
    cell.imageType1 = Clackamas;
}

return cell;
}

这是子类表viewcell：

- (id)initWithStyle:(UITableViewCellStylE)style reusEIDentifier:(NSString *)reusEIDentifier
{
if (self = [super initWithStyle:style reusEIDentifier:reusEIDentifier]) {

    callView = [[UIView alloc] initWithFrame:CGRectMake(7.5,7,305,65)];
    [callView setAutoresizingMask:UIViewAutoresizingFlexibleLeftMargin |
     UIViewAutoresizingFlexibleRightMargin |
     UIViewAutoresizingFlexibleWidth];
    [callView setContentMode:UIViewContentModeTopLeft];
    [callView setBACkgroundColor: [UIColor colorWithRed:240.0/255.0 green:240.0/255.0 blue:240.0/255.0 alpha:1.0]];
    callView.layer.borderWidth = 1.0;
    callView.layer.borderColor = [UIColor colorWithRed:(0/255.0)  green:(0/255.0)  blue:(0/255.0)  alpha:1.0].CGColor;

    [self.contentView addSubview:callView];

    callTypeLabel = [[UILabel alloc]initWithFrame:CGRectMake(5,2,190,21)];
    callTypeLabel.font = [UIFont boldSystemFontOfSize:12.0];
    callTypeLabel.textColor = [UIColor blackColor];
    callTypeLabel.BACkgroundColor = [UIColor clearColor];
    callTypeLabel.highlightedTextColor = [UIColor whiteColor];
    callTypeLabel.adjustsFontSizeToFitWidth = YES;
    [callView addSubview:callTypeLabel];

    LOCATIOnLabel = [[UILabel alloc]initWithFrame:CGRectMake(5,17,15)];
    LOCATIOnLabel.font = [UIFont systemFontOfSize:10.0];
    LOCATIOnLabel.textColor = [UIColor blackColor];
    LOCATIOnLabel.BACkgroundColor = [UIColor clearColor];
    LOCATIOnLabel.highlightedTextColor = [UIColor whiteColor];
    LOCATIOnLabel.adjustsFontSizeToFitWidth = YES;
    [callView addSubview:LOCATIOnLabel];

    unitsLabel = [[UILabel alloc]initWithFrame:CGRectMake(4,43,21)];
    unitsLabel.font = [UIFont systemFontOfSize:10.0];
    unitsLabel.textColor = [UIColor blackColor];
    unitsLabel.BACkgroundColor = [UIColor clearColor];
    unitsLabel.highlightedTextColor = [UIColor whiteColor];
    unitsLabel.adjustsFontSizeToFitWidth = NO;
    [callView addSubview:unitsLabel];

    stationLabel = [[UILabel alloc]initWithFrame:CGRectMake(195,25,75,20)];
    stationLabel.font = [UIFont systemFontOfSize:12.0];
    stationLabel.textColor = [UIColor blackColor];
    stationLabel.BACkgroundColor = [UIColor clearColor];
    stationLabel.highlightedTextColor = [UIColor whiteColor];
    stationLabel.adjustsFontSizeToFitWidth = YES;
    [callView addSubview:stationLabel];

    CGRect countyImageFrame = CGRectMake(275,10,18,18);
    UIImageView *countyImageView = [[UIImageView alloc] initWithFrame:countyImageFrame];
    countyImageView.image = countyImage;
    [callView addSubview:countyImageView];

    CGRect callTypeImageFrame = CGRectMake(275,37,18);
    UIImageView *callTypeImageView = [[UIImageView alloc] initWithFrame:callTypeImageFrame];
    callTypeImageView.image = callTypeImage;
    [callView addSubview:callTypeImageView];

    SELEctionView = [[UIView alloc] initWithFrame:CGRectMake(10,200,65)];
    [SELEctionView setBACkgroundColor: [UIColor clearColor]];

    }

    return self;
}

- (void)setImageType:(CallTypE)newImageType {
imageType = newImageType;

if (imageType == FirE) {
    CGRect callTypeImageFrame = CGRectMake(275,18);
    UIImageView *callTypeImageView = [[UIImageView alloc] initWithFrame:callTypeImageFrame];
    callTypeImageView.image = [UIImage imagenamed:@"red.png"];
    [callView addSubview:callTypeImageView];
}
else if (imageType == EMS) {
    CGRect callTypeImageFrame = CGRectMake(275,18);
    UIImageView *callTypeImageView = [[UIImageView alloc] initWithFrame:callTypeImageFrame];
    callTypeImageView.image = [UIImage imagenamed:@"yellow.png"];
    [callView addSubview:callTypeImageView];
    }
}

- (void)setImageType1:(county)newImageType1 {
imageType1 = newImageType1;

if (imageType1 == Washington) {
    CGRect callTypeImageFrame = CGRectMake(275,18);
    UIImageView *countyImageView = [[UIImageView alloc] initWithFrame:callTypeImageFrame];
    countyImageView.image = [UIImage imagenamed:@"blue.png"];
    [callView addSubview:countyImageView];
}
else if (imageType1 == Clackamas) {
    CGRect callTypeImageFrame = CGRectMake(275,18);
    UIImageView *countyImageView = [[UIImageView alloc] initWithFrame:callTypeImageFrame];
    countyImageView.image = [UIImage imagenamed:@"green.png"];
    [callView addSubview:countyImageView];
    }
}

UIImageView *callTypeImageView = [[UIImageView alloc] initWithFrame:callTypeImageFrame];
callTypeImageView.image = [UIImage imagenamed:@"red.png"];
[callView addSubview:callTypeImageView];