我有一个 UItableViewCell ，我正在 tableView:CellForRowAtIndexpath 内以编程方式创建它，在您滚动一段时间后性能不佳。
我最初将它作为InterfaceBuilder中的自定义UITableViewCell，但是我没有以编程方式创建这个视图，它提高了大约40％的性能但是在滚动说40 - 100行之后它开始变得非常小故障..我正在考虑工作了解如何缓存单元格的 UITableView 的高度，但是如果它是我的代码中的一个基本错误，我现在会感到很痛苦。例如 mybe 我的双端队列不工作？我不确定如何检查这一点，并希望在诊断我的问题时得到一些帮助。
这就是我的 tableview 方法的样子
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
// Configure the cell...
cell.selectionStyle = UITableViewCellSelectionStyleNone;
if ([sortedItemsArray count] > 0) {
NSDictionary *currentInstallDictionary = [sortedItemsArray objectAtIndex:indexPath.row];
NSNumber *tempDUP = [currentInstallDictionary objectForKey:@"dup"];
NSInteger myInteger = [tempDUP integerValue];
if (myInteger == 0) {
//assign vals to labels
areaLabel = [[UILabel alloc] initWithFrame:CGRectMake(10.0, -2.0, 140.0, 35.0)];
NSString *areaString = [currentInstallDictionary objectForKey:@"area"];
if ((NSNull *) areaString != [NSNull null]) {
areaLabel.text = areaString;
} else {
areaLabel.text = @" ";
}
areaLabel.lineBreakMode = NSLineBreakByCharWrapping;
areaLabel.numberOfLines = 0;
[areaLabel sizeToFit];
[cell addSubview:areaLabel];
// removed other UIlabel that were here for readability
descriptionLabel = [[UILabel alloc] initWithFrame:CGRectMake(450.0, 5.0, 140.0, 35.0)];
NSString *descriptionString = [currentInstallDictionary objectForKey:@"partDesc"];
if ((NSNull *) descriptionString != [NSNull null]) {
descriptionLabel.text = descriptionString;
} else {
descriptionLabel.text = @" ";
}
descriptionLabel.lineBreakMode = NSLineBreakByCharWrapping;
descriptionLabel.numberOfLines = 0;
[descriptionLabel sizeToFit];
[cell addSubview:descriptionLabel];
shipmentLabel = [[UILabel alloc] initWithFrame:CGRectMake(605.0, 5.0, 140.0, 35.0)];
NSString *shipString = [currentInstallDictionary objectForKey:@"totShip"];
if ((NSNull *) shipString != [NSNull null]) {
shipmentLabel.text = shipString;
} else {
shipmentLabel.text = @" ";
}
shipmentLabel.lineBreakMode = NSLineBreakByCharWrapping;
shipmentLabel.numberOfLines = 0;
[shipmentLabel sizeToFit];
[cell addSubview:shipmentLabel];
quantityALabel = [[UILabel alloc] initWithFrame:CGRectMake(755.0, 5.0, 50.0, 35.0)];
NSString *totDryQtyString = [currentInstallDictionary objectForKey:@"totDryQty"];
if ((NSNull *) totDryQtyString != [NSNull null]) {
quantityALabel.text = totDryQtyString;
} else {
quantityALabel.text = @" ";
}
quantityALabel.lineBreakMode = NSLineBreakByCharWrapping;
quantityALabel.numberOfLines = 0;
[quantityALabel sizeToFit];
[cell addSubview:quantityALabel];
quantityBLabel = [[UILabel alloc] initWithFrame:CGRectMake(815.0, 5.0, 50.0, 35.0)];
NSString *totInsQtyString = [currentInstallDictionary objectForKey:@"totInsQty"];
if ((NSNull *) totInsQtyString != [NSNull null]) {
quantityBLabel.text = totInsQtyString;
} else {
quantityBLabel.text = @" ";
}
quantityBLabel.lineBreakMode = NSLineBreakByCharWrapping;
quantityBLabel.numberOfLines = 0;
[quantityBLabel sizeToFit];
[cell addSubview:quantityBLabel];
NSString *tDStateAString = [currentInstallDictionary objectForKey:@"totDryStateA"];
NSString *tDStateBString = [currentInstallDictionary objectForKey:@"totDryStateB"];
fitButtonImage = [UIButton buttonWithType:UIButtonTypeCustom];
fitButtonImage.frame = CGRectMake(888.0, 5.0, 35.0, 35.0);
if (([tDStateAString isEqualToString:@"T"]) && ([tDStateBString isEqualToString:@"W"])) {
UIImage *checkedOnImage = [UIImage imageNamed:@"CheckedOn.png"];
[fitButtonImage setImage:checkedOnImage forState:UIControlStateNormal];
[cell addSubview:fitButtonImage];
} else if (([tDStateAString isEqualToString:@"T"]) && ([tDStateBString isEqualToString:@"R"])) {
UIImage *checkedOnDisabledImage = [UIImage imageNamed:@"CheckedOnDisabled.png"];
[fitButtonImage setImage:checkedOnDisabledImage forState:UIControlStateNormal];
[cell addSubview:fitButtonImage];
} else {
if (![quantityALabel.text isEqualToString:@"0"]) {
UIImage *checkedOffImage = [UIImage imageNamed:@"CheckedOff.png"];
[fitButtonImage setImage:checkedOffImage forState:UIControlStateNormal];
fitButtonImage.userInteractionEnabled = YES;
} else {
fitButtonImage.userInteractionEnabled = NO;
}
}
NSString *tIStateAString = [currentInstallDictionary objectForKey:@"totInstStateA"];
NSString *tIStateBString = [currentInstallDictionary objectForKey:@"totInstStateB"];
insButtonImage = [UIButton buttonWithType:UIButtonTypeCustom];
insButtonImage.frame = CGRectMake(968.0, 5.0, 35.0, 35.0);
if (([tIStateAString isEqualToString:@"T"]) && ([tIStateBString isEqualToString:@"W"])) {
UIImage *checkedOnImage = [UIImage imageNamed:@"CheckedOn.png"];
[insButtonImage setImage:checkedOnImage forState:UIControlStateNormal];
[cell addSubview:insButtonImage];
} else if (([tIStateAString isEqualToString:@"T"]) && ([tIStateBString isEqualToString:@"R"])) {
UIImage *checkedOnDisabledImage = [UIImage imageNamed:@"CheckedOnDisabled.png"];
[insButtonImage setImage:checkedOnDisabledImage forState:UIControlStateNormal];
[cell addSubview:insButtonImage];
} else {
UIImage *checkedOffImage = [UIImage imageNamed:@"CheckedOff.png"];
[insButtonImage setImage:checkedOffImage forState:UIControlStateNormal];
[cell addSubview:insButtonImage];
}
//add lines to cell
lineBreakOneView = [[UIView alloc] initWithFrame:CGRectMake(140.0, 0.0, 0.5, 44.0)];
lineBreakOneView.backgroundColor = [UIColor lightGrayColor];
[cell addSubview:lineBreakOneView];
lineBreakTwoView = [[UIView alloc] initWithFrame:CGRectMake(290.0, 0.0, 0.5, 44.0)];
lineBreakTwoView.backgroundColor = [UIColor lightGrayColor];
[cell addSubview:lineBreakTwoView];
lineBreakThreeView = [[UIView alloc] initWithFrame:CGRectMake(440.0, 0.0, 0.5, 44.0)];
lineBreakThreeView.backgroundColor = [UIColor lightGrayColor];
[cell addSubview:lineBreakThreeView];
lineBreakFourView = [[UIView alloc] initWithFrame:CGRectMake(590.0, 0.0, 0.5, 44.0)];
lineBreakFourView.backgroundColor = [UIColor lightGrayColor];
[cell addSubview:lineBreakFourView];
lineBreakFiveView = [[UIView alloc] initWithFrame:CGRectMake(745.0, 0.0, 0.5, 44.0)];
lineBreakFiveView.backgroundColor = [UIColor lightGrayColor];
[cell addSubview:lineBreakFiveView];
lineBreakSixView = [[UIView alloc] initWithFrame:CGRectMake(805.0, 0.0, 0.5, 44.0)];
lineBreakSixView.backgroundColor = [UIColor lightGrayColor];
lineBreakSixView.alpha = 0.3;
[cell addSubview:lineBreakSixView];
lineBreakSevenView = [[UIView alloc] initWithFrame:CGRectMake(865.0, 0.0, 0.5, 44.0)];
lineBreakSevenView.backgroundColor = [UIColor lightGrayColor];
[cell addSubview:lineBreakSevenView];
lineBreakEightView = [[UIView alloc] initWithFrame:CGRectMake(945.0, 0.0, 0.5, 44.0)];
lineBreakEightView.backgroundColor = [UIColor lightGrayColor];
lineBreakEightView.alpha = 0.3;
[cell addSubview:lineBreakEightView];
return cell;
}
}
return cell; // this shouldnt happen if the data is correct
}
实际上那里还有更多标签..所以它是一个相当复杂的 UITableViewCell ，我也想添加更多图像等等......但在我这样做之前，我需要帮助解决我的性能问题我正在受苦。
任何想法或帮助解决我的 UITableView 的滚动性能将不胜感激。