我想访问一个 URL 并从这个 URL 检索数据,基于检索到的数据我想从另一个 URL 检索数据
我尝试通过以下方式访问多个 URL:
- (void) showClassRoom:(NSString *)theMessage{
NSString *queryURL =[NSString stringWithFormat:@"http://nobert.cloudfoundry.com/CalOfEvents/tos"];
NSURL *url = [NSURL URLWithString: queryURL];
NSURLRequest *req = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
NSError *error;
NSURLResponse *response;
NSData *returnData = [NSURLConnection sendSynchronousRequest:req returningResponse:&response error:&error];
if(returnData){
NSString *strResult = [[NSString alloc] initWithBytes:[returnData bytes] length:[returnData length] encoding:NSUTF8StringEncoding];
NSDictionary *result = [strResult JSONValue];
for(id theKey in result){
for(id hello in theKey){
NSLog(@"The key:%@, The value:%@",hello,[theKey objectForKey:hello]);
}
}
if(TRUE){//based on some condition secondShowClassRoom is called
[self secondShowClassRoom];
}
}
}
- (void) secondShowClassRoom{
NSString *queryURL =[NSString stringWithFormat:@"http://nobert.cloudfoundry.com/CalOfEvents/to"];
NSURL *url = [NSURL URLWithString: queryURL];
NSURLRequest *req = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
NSError *error;
NSURLResponse *response;
NSData *returnData = [NSURLConnection sendSynchronousRequest:req returningResponse:&response error:&error];
if(returnData){
NSString *strResult = [[NSString alloc] initWithBytes:[returnData bytes] length:[returnData length] encoding:NSUTF8StringEncoding];
NSDictionary *result = [strResult JSONValue];
for(id theKey in result){
for(id hello in theKey){
NSLog(@"The key:%@, The value:%@",hello,[theKey objectForKey:hello]);
}
}
}
}
这会非常缓慢地检索数据,并且当我在增强现实上开发应用程序时,我的应用程序需要非常快速的访问
还有另一种更快的方法,但是我无法访问多个 URL:
- (void) showClassRoom:(NSString *)theMessage{
NSString *queryURL =[NSString stringWithFormat:@"http://nobert.cloudfoundry.com/CalOfEvents/to"];
NSURL *url = [NSURL URLWithString: queryURL];
NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:url];
conn = [[NSURLConnection alloc] initWithRequest:req delegate:self];
if (conn) {
webData = [[NSMutableData data] retain];
}
classRoomControl.hidden = NO;
labControl.hidden = YES;
placementControl.hidden = YES;
}
-(void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *) response{
[webData setLength: 0]; }
-(void) connection:(NSURLConnection *)connection didReceiveData:(NSData *) data {
[webData appendData:data];
}
-(void) connection:(NSURLConnection *)connection didFailWithError:(NSError *) error {
[conn release];
[webData release];
}
-(void) connectionDidFinishLoading:(NSURLConnection *) connection {
[conn release];
NSLog(@"DONE. Received Bytes: %d", [webData length]);
NSString *strResult = [[NSString alloc] initWithBytes:[webData mutableBytes] length:[webData length] encoding:NSUTF8StringEncoding];
NSDictionary *result = [strResult JSONValue];
for(id theKey in result){
for(id hello in theKey){
NSLog(@"The key:%@, The value:%@",h,hello);
}
}
[strResult release];
[webData release];
}
请帮助我。任何帮助将不胜感激..