我使用的NSData的initWithContentsOfURL从URL中加载图像。 不过，我不知道该图像的大小事先和我想的连接停止或失败，如果响应超过一定规模。
有没有办法在iPhone 3.0做到这一点？
提前致谢。
Answer 1:
你不能直接做它通过NSData的但是NSURLConnection的将通过异步加载图像和使用连接支持这样的事情：didReceiveData：检查你有多少数据接收。 如果你去了你的极限只是发送取消消息NSURLConnection的停止请求。
简单的例子：（receivedData在头作为NSMutableData定义）
@implementation TestConnection
- (id)init {
[self loadURL:[NSURL URLWithString:@"http://stackoverflow.com/content/img/so/logo.png"]];
return self;
}
- (BOOL)loadURL:(NSURL *)inURL {
NSURLRequest *request = [NSURLRequest requestWithURL:inURL];
NSURLConnection *conn = [NSURLConnection connectionWithRequest:request delegate:self];
if (conn) {
receivedData = [[NSMutableData data] retain];
} else {
return FALSE;
}
return TRUE;
}
- (void)connection:(NSURLConnection *)conn didReceiveResponse:(NSURLResponse *)response {
[receivedData setLength:0];
}
- (void)connection:(NSURLConnection *)conn didReceiveData:(NSData *)data {
[receivedData appendData:data];
if ([receivedData length] > 5120) { //5KB
[conn cancel];
}
}
- (void)connectionDidFinishLoading:(NSURLConnection *)conn {
// do something with the data
NSLog(@"Succeeded! Received %d bytes of data", [receivedData length]);
[receivedData release];
}
@end
文章来源: Load image from url in iPhone, only if small
