当我加载与此类关联的 View 时,我似乎无法调用委托(delegate)方法。它们都没有触发。我敢肯定这是我忽略的事情,但我终生无法弄清楚原因。
下载更新.h
#import <UIKit/UIKit.h>
@interface DownloadUpdates : UIViewController
@property (strong, nonatomic) NSMutableData *responseData;
@property (strong, nonatomic) NSURLConnection *connection;
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response;
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data;
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error;
- (void)connectionDidFinishLoading:(NSURLConnection *)connection;
@end
下载更新.m
出于保护隐私的目的,该 URL 已被删除,但它只是调用将返回 JSON 数据的 API。此 URL 按预期运行,因此它是代码问题。
#import "DownloadUpdates.h"
@interface DownloadUpdates ()
@end
@implementation DownloadUpdates
- (void)connection:(NSURLConnection *)_connection didReceiveResponse:(NSURLResponse *)response
{
_responseData = [[NSMutableData alloc] init];
NSLog(@"Response received");
}
- (void)connection:(NSURLConnection *)_connection didReceiveData:(NSData *)data
{
[_responseData appendData:data];
NSLog(@"Data received");
}
- (void)connection:(NSURLConnection *)_connection didFailWithError:(NSError *)error
{
NSLog(@"Unable to fetch data");
}
- (void)connectionDidFinishLoading:(NSURLConnection *)_connection
{
NSLog(@"Succeeded! Received %d bytes of data",[_responseData
length]);
// NSString *txt = [[NSString alloc] initWithData:_responseData encoding: NSASCIIStringEncoding];
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
NSURL *myURL = [NSURL URLWithString:@"URL HERE"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:myURL cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:60];
_connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
// Do any additional setup after loading the view.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
如果您能提供任何帮助/建议,我将不胜感激。
最佳答案
使用属性应用强修饰符:
self.responsedata = [[NSMutableData alloc] init];
(.....)
self.connection = [[NSURLConnection alloc] initWithRequest: ....etc...
关于iphone - 如何让 NSURLConnection 委托(delegate)方法触发?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17026311/