Question

大家好！我只想问我在做什么有什么问题。我正在使用这两天，但我仍然无法做到。它说“无法识别的选择器发送到实例0x748b800”。我正在做的是解析json返回的值。以下是json返回值的示例：

{
   "data": [
      {
         "name": "John Patola",
         "id": "123444432"
      },
      {
         "name": "Joshua Valdez",
         "id": "22234567778"
      }
]
}

我想将它们存储在一个名为的数组中 NSArray *storage。以下是我的代码：

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
[self.rData appendData:data];
}
-(void)connection: (NSURLConnection *)connection didFailWithError:(NSError *)error{
[rData release];
[connection release];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection{
NSString *myVar = [[[NSString alloc] initWithData:rData encoding:NSUTF8StringEncoding] autorelease];
NSArray *storage =[[(NSDictionary *)myVar objectForKey:@"data"]retain]; // this line seems to be the error
NSLog(@"%i", [storage count]);

当我运行此代码时，出现错误“无法识别的选择器发送到实例0x748b800”。你认为我标记的那条线真的会出错吗？我该如何解决？提前谢谢你的帮助。 ; - ）

Answer 1

在项目中添加JSON工具包。

在viewController.h文件中声明方法

-(void)JsonParsing:(NSString *)string;

然后导入

#import "SBJSON.h"
#import "JSON.h"

在您的viewController.m文件和

中

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
    [self.rData appendData:data];
}
-(void)connection: (NSURLConnection *)connection didFailWithError:(NSError *)error
{
    [rData release];
    [connection release];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
 {
    NSString *theXMLString = [[NSString alloc]initWithBytes:[self.rData mutableBytes] length:[self.rData length] encoding:NSUTF8StringEncoding];
    [self JsonParsing:theXMLString];
 }

然后在这里解析你的字符串 -

-(void)JsonParsing:(NSString *)string
{
    SBJSON *jsonObject = [[SBJSON alloc]init];
    NSArray *dataArray = [[NSArray alloc]init];
    dataArray = [jsonObject objectWithString:string];
    NSLog(@"%d", [dataArray count]);

}

Answer 2

这样做：

 -(void)connectionDidFinishLoading:(NSURLConnection *)connection{

   NSError *error = nil;
   NSDictionary *jsonDict = [NSJSONSerialization JSONObjectWithData: rData options: NSJSONReadingMutableContainers error: &error];

   if (!jsonArray) {
      NSLog(@"Error parsing JSON data: %@", e);
   } else 
   {
      NSArray *arrValues = [jsonDict objectForKey:@"data"];
      for(NSDictionary *item in arrValues) {
      NSLog(@"Item: %@", item);
   }
}

无法识别的选择器发送到实例0x748b800

2 个答案: