Ios 为什么我的应用程序在使用[NSAttributedString initWithData]进行后台处理时崩溃
我有一个管理UICollectionView的viewController。我有一个从cellForItemAtIndexPath调用的helper方法，该方法为单元格中的标签提供NSAttribute字符串。helper方法从html字符串格式化NSAttributedString。当移动到后台时，应用程序将崩溃，但仅当indexath.item大于1时。换句话说，我可以退出应用程序，而不会从第一个或第二个单元格崩溃，但在第三个、第四个、第三个、第三个、第三个、第三个、第三个、第三个、第三个、第三个、第三个、第三个、第三个、第三个、第三个。。。牢房 这是我的助手方法和堆栈跟踪。知道我为什么退出应用程序会崩溃吗Ios 为什么我的应用程序在使用[NSAttributedString initWithData]进行后台处理时崩溃,ios,Ios,我有一个管理UICollectionView的viewController。我有一个从cellForItemAtIndexPath调用的helper方法，该方法为单元格中的标签提供NSAttribute字符串。helper方法从html字符串格式化NSAttributedString。当移动到后台时，应用程序将崩溃，但仅当indexath.item大于1时。换句话说，我可以退出应用程序，而不会从第一个或第二个单元格崩溃，但在第三个、第四个、第三个、第三个、第三个、第三个、第三个、第三个、第三个、
#pragma mark - === Utility Methods === -
- (NSAttributedString *)stepDescriptionStringForIndexPath:(NSIndexPath *)indexPath {
NSString *headerString;
NSString *htmlString;
NSString *categoryString = [NSString stringWithFormat:@"Category: %@", self.knot.category.categoryName];
NSString *abokString = [NSString stringWithFormat:@"ABOK #: %@", self.knot.abokNumber];
NSMutableString *activitiesString = [NSMutableString stringWithCapacity:10];
[activitiesString appendString:@"Activities: "];
// build a string of activities to append to the description html
NSArray *activities = [self.knot.activities allObjects];
if ([activities count] > 0) {
int counter = 1;
for (Activity *activity in activities) {
[activitiesString appendString:activity.activityName];
if (counter < [activities count]) {
[activitiesString appendString:@", "];
}
counter ++;
}
}
// build an HTML string by concatinating the activities to the step description
// and add the header string
if(indexPath.item > 0){
Step *step = (Step *)self.steps[indexPath.item - 1];
headerString = [NSString stringWithFormat:@"Step %ld of %lu", (long)indexPath.item, (unsigned long)[self.steps count]];
htmlString =[NSString stringWithFormat:@"<p>%@</p>%@", headerString, step.stepDescription];
} else {
headerString = @"Overview";
htmlString = [NSString stringWithFormat:@"<p>%@</p>%@<p>%@</br>%@</br>%@</p>", headerString, self.knot.knotDescription, categoryString, abokString, activitiesString];
}
// convert the html string to an attributed string
NSMutableAttributedString *attrStringFromHTML = [[NSMutableAttributedString alloc] initWithData:[htmlString dataUsingEncoding:NSUTF8StringEncoding]
options:@{NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType,
NSCharacterEncodingDocumentAttribute: [NSNumber numberWithInt:NSUTF8StringEncoding]}
documentAttributes:nil
error:nil];
// set the font for the body
NSRange totalRange;
totalRange.location = 0;
totalRange.length = attrStringFromHTML.length;
[attrStringFromHTML addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:16] range:totalRange];
// set the font for the header
NSString *temp = [attrStringFromHTML string];
NSRange headerRange = [temp rangeOfString:headerString];
NSRange categoryRange = [temp rangeOfString:categoryString];
NSRange abokRange = [temp rangeOfString:abokString];
NSRange activitiesRange = [temp rangeOfString:activitiesString];
[attrStringFromHTML addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:18] range:headerRange];
//set the font for the activities paragraph
if(indexPath.item == 1){
[attrStringFromHTML addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:12] range:categoryRange];
[attrStringFromHTML addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:12] range:abokRange];
[attrStringFromHTML addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:12] range:activitiesRange];
}
return attrStringFromHTML;
}
#pragma标记-==实用方法===-
-（NSAttributeString*）stepDescriptionStringForIndexPath:（NSIndexPath*）indexPath{
NSString*头串；
NSString*htmlString；
NSString*categoryString=[NSString stringWithFormat:@“Category:%@”，self.knot.Category.categoryName]；
NSString*abokString=[NSString stringWithFormat:@“ABOK:%@”，self.knot.abokNumber]；
NSMutableString*activitiesString=[NSMutableString stringWithCapacity:10]；
[activitiesString appendString:@“活动：”；
//构建要附加到html描述的活动字符串
NSArray*activities=[self.knot.activities allObjects]；
如果（[活动计数]>0）{
int计数器=1；
用于（活动*活动中的活动）{
[activitiesString appendString:activity.activityName]；
如果（计数器<[活动计数]）{
[activitiesString appendString:@“，”；
}
计数器++；
}
}
//通过将活动关联到步骤描述来构建HTML字符串
//并添加标题字符串
如果（indexath.item>0）{
Step*Step=（Step*）self.steps[indexPath.item-1]；
headerString=[NSString stringWithFormat:@“步骤%ld，共%lu”，（长）indexath.item，（未签名的长）[self.steps count]]；
htmlString=[NSString stringWithFormat:@“%@%@”，标题字符串，步骤.步骤说明]；
}否则{
headerString=@“概述”；
htmlString=[NSString STRINGWITH FORMAT:@“%@%@%@%@”，标题字符串，self.knot.knotDescription，categoryString，abokString，activitiesString]；
}
//将html字符串转换为属性字符串
NSMUTABLeAttributeString*attrStringFromHTML=[[NSMUTABLeAttributeString alloc]initWithData:[htmlString dataUsingEncoding:NSUTF8StringEncoding]
选项：@{NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType，
NSCharacterEncodingDocumentAttribute:[NSNumber numberWithInt:NSUTF8StringEncoding]}
文件属性：无
错误：无]；
//设置正文的字体
NSRange总范围；
totalRange.location=0；
totalRange.length=attrStringFromHTML.length；
[attrStringFromHTML addAttribute:NSFontAttributeName值：[UIFont systemFontOfSize:16]范围：totalRange]；
//设置标题的字体
NSString*temp=[attrStringFromHTML字符串]；
NSRange headerRange=[temp rangeOfString:headerString]；
NSRange categoryRange=[temp rangeOfString:categoryString]；
NSRange abokRange=[temp rangeOfString:abokString]；
NSRange activitiesRange=[temp rangeOfString:activitiesString]；
[attrStringFromHTML addAttribute:NSFontAttributeName值：[UIFont boldSystemFontOfSize:18]范围：headerRange]；
//设置活动段落的字体
if（indexath.item==1）{
[attrStringFromHTML addAttribute:NSFontAttributeName值：[UIFont systemFontOfSize:12]范围：categoryRange]；
[attrStringFromHTML addAttribute:NSFontAttributeName值：[UIFont systemFontOfSize:12]范围：abokRange]；
[attrStringFromHTML addAttribute:NSFontAttributeName值：[UIFont systemFontOfSize:12]范围：活动范围]；
}
从HTML返回属性字符串；
}
DispatchQueue.MainQueue.DispatchAsync(() =>
{
var encodingData = ((NSString)html).Encode(NSStringEncoding.Unicode, true);
NSAttributedString data = new NSAttributedString(
encodingData,
new NSAttributedStringDocumentAttributes()
{
DocumentType = NSDocumentType.HTML,
}, ref error);
});