Как получить массив из NSMutablatedata
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09-12-2019 - |
Вопрос
У меня есть текстовый файл с 5 строками.Мне нужно использовать NSURLConnection, чтобы получить кондентунт этого файла.Но NSLog показывает мне, что «дамп» пусто.Как я могу преобразовать данные из NSMutBabledata в Nsarray.Массивы - это потому, что мне нужно показать эти 5 элементов в табличном обзоре.
NSURLRequest *theRequest=[NSURLRequest
requestWithURL:[NSURL URLWithString:@"http://dl.dropbox.com/u/25105800/names.txt"]
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:60.0];
NSURLConnection *theConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if (theConnection) {
receivedData = [NSMutableData data];
NSString *dump = [[NSString alloc] initWithData:receivedData
encoding:NSUTF8StringEncoding];
NSLog(@"data: %@", dump);
NSArray *outputArray=[dump componentsSeparatedByString:@"\n"];
self.namesArray = outputArray;
.
Спасибо заранее.WTW URL работает, вы можете увидеть файл.
Решение
If you don't want to use a delegate, you can use a synchronous call with NSURLConnection, like this:
NSURLRequest *theRequest=[NSURLRequest
requestWithURL:[NSURL URLWithString:@"http://dl.dropbox.com/u/25105800/names.txt"]
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:60.0];
NSError *error = nil;
NSHTTPURLResponse *response = nil;
NSData *receivedData = [NSURLConnection sendSynchronousRequest:theRequest response:&response error:&error];
if (error == nil) {
NSString *dump = [[NSString alloc] initWithData:receivedData
encoding:NSUTF8StringEncoding];
NSLog(@"data: %@", dump);
NSArray *outputArray=[dump componentsSeparatedByString:@"\n"];
self.namesArray = outputArray;
}
Just beware that this will not be running asynchronously. If you don't want it to run on the main thread and block your main thread/UI, consider using a separate thread to execute that code or use GCD.
Другие советы
Here's how you implement this solution with a delegate:
In your .h file:
@interface MyClass : NSObject <NSURLConnectionDelegate, NSURLConnectionDataDelegate>
@property (nonatomic, retain) NSMutableData *receivedData;
@property (nonatomic, retain) NSArray *namesArray;
@end
In you .m file:
@implementation MyClass
@synthesize receivedData = _receivedData;
@synthesize namesArray = _namesArray;
- (id)init {
self = [super init];
if (self) {
self.receivedData = [NSMutableData data];
NSURLRequest *theRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://dl.dropbox.com/u/25105800/names.txt"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
[connection start];
}
return self;
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
NSLog(@"Received response! %@", response);
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
[self.receivedData appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
NSString *dump = [[NSString alloc] initWithData:self.receivedData encoding:NSUTF8StringEncoding];
NSLog(@"data: %@", dump);
self.namesArray = [dump componentsSeparatedByString:@"\n"];
}
@end
You have to use the delegate, then save the received data into receivedData (which is of course empty right now.. you just initalized it.) and then you transform the data into a string, like you did it in your example. Have a look at NSURLConnectionDelegate
You need to implement the delegate methods for NSURLConnection to be notified of incoming data. You are using the asynchronous methods.
Also note that [NSMutableData data]
just creates an empty data-object.. so you can't expect it to contain any data..
I suggest you read https://developer.apple.com/library/ios/#documentation/Cocoa/Conceptual/URLLoadingSystem/Tasks/UsingNSURLConnection.html#//apple_ref/doc/uid/20001836-BAJEAIEE (completely!)