Question

我使用JSON解析通过使用php从MySql获取数据我得到了我想要的所有数据，但是当我想要打印这些数据时，我创建了一个for循环，但它只给了我最后一个元素..这是我的代码

在DidViewLoad中

：

- (void)viewDidLoad
{
[super viewDidLoad];

NSString *phpUrl = @"http://dt-works.com/eman/bookOwn.php"; 
NSString *dbName = @"dbName";
NSString *localHost = @"localhost";
NSString *dbUser = @"dbUser";
NSString *dbPwd = @"dbPwd";

int u_id = 1;
NSString *user_id = [NSString stringWithFormat:@"%d",u_id];

SBJsonParser *parser = [[SBJsonParser alloc] init];

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:phpUrl]];

[request setHTTPMethod:@"POST"];

NSString *post = [[NSString alloc] initWithFormat:@"dbName=%@&localHost=%@&dbUser=%@&dbPwd=%@&user_id=%@&submit=", dbName, localHost, dbUser, dbPwd, user_id];

[request setHTTPBody:[post dataUsingEncoding:NSUTF8StringEncoding]];

NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

NSString *json_string = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];

NSArray *statuses = [parser objectWithString:json_string error:nil];
int arraySize = [statuses count];


for (NSDictionary *status in statuses)
{

    bo_id2 = [status objectForKey:@"bo_id"];
    bo_name2 = [status objectForKey:@"bo_name"];
    bo_au_id2 = [status objectForKey:@"bo_au_id"];
    bo_pub_id2 = [status objectForKey:@"bo_pub_id"];
    bo_num_pages2 = [status objectForKey:@"bo_num_pages"];
    bo_publish_year2 = [status objectForKey:@"bo_publish_year"];
}

NSLog(@"size of array is: %d", arraySize);

for (int i=0; i<arraySize; i++) {
    NSLog(@"%d:",i);
    // here I want to retrieve all array elements .. when I try 
     NSLog(@"Book id: %@ - book name: %@", bookId, bookName); 
      // this give me the last elemet only not all data 
      // I want to get the data here to use it later .. how ???

}

}

任何帮助??

Answer 1

您似乎只是将每个对象的值重新分配给实例变量，实例变量仅指向一个对象，而不是指定给它的所有对象。

Answer 2

我不太明白为什么你必须在第一个循环中使用两个for循环来完成任务

NSMutableArray *books = [[NSMutableArray alloc] init];
for(NSDictionary *status in statuses){
  [books addObject:status];
}

稍后，当您想要检索任何图书时，只需拨打[books objectAtIndex:index]即可。希望这可以提供帮助。您应该能够完成您要求的所有任务。

修改如果您只想要一个元素，例如bo_name，您可以使用：

NSMutableArray *books =[[NSMutableArray alloc] init]; for(NSDictionary *status in statuses){ [books addObject:[status objectForKey:@"bo_name"]]; }

Answer 3

最有可能你必须将数组重新定位到某个地方。检查整个代码。

Answer 4

NSLog(@"Book id: %@ - book name: %@", bookId, bookName);

如何在上面的NSLog中获取bookId和bookName值？你的代码中缺少一些东西。

你可以试试这个：

for(NSDictionary *status in statuses) {
   NSLog(@"Book id: %@ - Book Name: %@", [status objectForKey:@"bo_id"], [status objectForKey: @"bo_name"]);
}

换句话说，如果您想使用第二个for循环，请使用与第一个相同的方式。

检索nsarray的所有数据

4 个答案: