存储数据时出现问题

Question

我无法获取我存储的数据......这是代码：

 if ([string isEqualToString:@""]) {
        //RECUPERO DATA 
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
        NSString *pathToDocuments=[paths objectAtIndex:0];
        pathToDocuments=[pathToDocuments stringByAppendingString:@"getSubscriptionsListShowOnlyWithUnreadFeeds.txt"];
        NSLog(pathToDocuments);
        dataReply=[[NSData alloc] initWithContentsOfFile:pathToDocuments];
        NSString *string = [[NSString alloc] initWithData:dataReply encoding:NSASCIIStringEncoding];
        NSLog(@"string recuperata %@",string);
    }
    if ([string isEqualToString:@""]==NO) {
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
        NSString *pathToDocuments=[paths objectAtIndex:0];
        pathToDocuments=[pathToDocuments stringByAppendingString:@"getSubscriptionsListShowOnlyWithUnreadFeeds.txt"];
        NSLog(pathToDocuments);
        [dataReply writeToFile:pathToDocuments atomically:YES];}

有什么问题吗？

编辑 没有错误，没有崩溃，但是 NSLog(@"string recuperata %@",string); 打印一个空字符串！ （数据存储在设备中，因为当字符串！=空时我至少运行过一次我的应用程序 谢谢

Answer 1

    if ([string length]<=0) {
            //RECUPERO DATA 
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
        NSString *pathToDocuments=[paths objectAtIndex:0];
        pathToDocuments=[pathToDocuments stringByAppendingString:@"getSubscriptionsListShowOnlyWithUnreadFeeds.txt"];
        NSLog(pathToDocuments);
        dataReply=[[NSData alloc] initWithContentsOfFile:pathToDocuments];
        NSString *string = [[NSString alloc] initWithData:dataReply encoding:NSASCIIStringEncoding];
        NSLog(@"string recuperata %@",string);
    }

    else {

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
        NSString *pathToDocuments=[paths objectAtIndex:0];
        pathToDocuments=[pathToDocuments stringByAppendingString:@"getSubscriptionsListShowOnlyWithUnreadFeeds.txt"];
        NSLog(pathToDocuments);
        [dataReply writeToFile:pathToDocuments atomically:YES];

    }

Answer 2

我认为第二个 if 缺少 else 。我不确定这是否是您想要的，或者是否是您的拼写错误。检查这是否是问题所在。

 if ([string isEqualToString:@""]) {
        //RECUPERO DATA 
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
        NSString *pathToDocuments=[paths objectAtIndex:0];
        pathToDocuments=[pathToDocuments stringByAppendingString:@"getSubscriptionsListShowOnlyWithUnreadFeeds.txt"];
        NSLog(pathToDocuments);
        dataReply=[[NSData alloc] initWithContentsOfFile:pathToDocuments];
        NSString *string = [[NSString alloc] initWithData:dataReply encoding:NSASCIIStringEncoding];
        NSLog(@"string recuperata %@",string);
    } else if ([string isEqualToString:@""]==NO) {
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
        NSString *pathToDocuments=[paths objectAtIndex:0];
        pathToDocuments=[pathToDocuments stringByAppendingString:@"getSubscriptionsListShowOnlyWithUnreadFeeds.txt"];
        NSLog(pathToDocuments);
        [dataReply writeToFile:pathToDocuments atomically:YES];

Answer 3

如果您不确定编码，请尝试更改为 NSUTF8StringEncoding，通常它可以工作。