在我的程序中，我有一个NSMutableData变量，它从http://www.nhara.org/scored_races-2013.htm收集信息。在大约第三次从网站获取信息之后，当它包含90810字节时，它消失了或变为null，因为如果我将其打印为NSString，则它为null。这是代码
- (void)viewWillAppear:(BOOL)animated
{
// Create a new data container for the stuff that comes back from the service
xmlData = [[NSMutableData alloc] initWithCapacity:180000];
[self fetchEntries];
[super viewWillAppear:animated];
}
- (void)fetchEntries
{
// Construct a URL that will ask the service for what you want
NSURL *url = [NSURL URLWithString: @"http://www.nhara.org/scored_races-2013.htm"];//
// Put that URL into an NSURLRequest
NSURLRequest *req = [NSURLRequest requestWithURL:url];
// Create a connection that will exchange this request for data from the URL
connection = [[NSURLConnection alloc] initWithRequest:req delegate:self startImmediately:YES];
}
- (void)connection:(NSURLConnection *)conn didReceiveData:(NSData *)data
{
// Add the incoming chunk of data to the container we are keeping
// The data always comes in the correct order
[xmlData appendData:data];
NSLog(@"%@",xmlData);
NSString *xmlCheck = [[[NSString alloc] initWithData:xmlData encoding:NSUTF8StringEncoding]autorelease];
NSLog(@"xmlCheck = %@", xmlCheck);
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
NSLog(@"error= %@",error);
}
- (void)connectionDidFinishLoading:(NSURLConnection *)conn {
// We are just checking to make sure we are getting the XML
NSString *xmlCheck = [[[NSString alloc] initWithData:xmlData encoding:NSUTF8StringEncoding] autorelease];
NSLog(@"xmlCheck2 = %@", xmlCheck);
}
最让我感到困惑的是，我的NSMutableData存储数据，但是在声称具有相同数量的字节时丢失了数据。
NSMutableData的大小是否受到限制？或者我的问题仅仅是内存管理吗？
最佳答案
您需要为xmlData变量创建一个属性。在您的头文件之后
@interface MyClass，像这样
@property (nonatomic, retain) NSMutableData * xmlData;
如果您使用的是ARC，则将其保留为坚固，如果使用的是低于ARC，则将其更改为保留。当您想使用变量时，请执行
self.xmlData关于ios - NSMutableData消失，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/13770770/