ios - NSJSONSerialization 编译器警告

Question

我正在使用 JSON 来填充带有标记的 mapView。

在方法 -(void)connectionDidFinishLoading:(NSURLConnection *)connection

编译器显示警告:

Incompatible pointer to integer conversion sending 'void *' to parameter of type 'NSJSONReadingOptions' (aka 'enum NSJSONReadingOptions')

在行

categorias_first = [NSJSONSerialization JSONObjectWithData:data_for_first_connection options:nil error:nil];
categorias_second = [NSJSONSerialization JSONObjectWithData:data_for_second_connection options:nil error:nil];
categorias_third = [NSJSONSerialization JSONObjectWithData:data_for_third_connection options:nil error:nil];

这是整个方法代码:

-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    //if data received network indicator not visible
    [UIApplication sharedApplication].networkActivityIndicatorVisible=NO;

    if(connection==first_connection) {

        categorias_first = [NSJSONSerialization JSONObjectWithData:data_for_first_connection options:nil error:nil];

    }
    else if(connection==second_connection){

        categorias_second = [NSJSONSerialization JSONObjectWithData:data_for_second_connection options:nil error:nil];
    }
    else if(connection==third_connection){

        categorias_third = [NSJSONSerialization JSONObjectWithData:data_for_third_connection options:nil error:nil];
    }

}

欢迎任何避免警告的帮助。

Answer 1

nil 被视为 ((void*)0) 并且具有指针类型，但是 NSJSONReadingOptions(作为枚举)是整数类型.

将 options:nil 替换为 options:0

例如:

    categorias_first = [NSJSONSerialization JSONObjectWithData:data_for_first_connection options:0 error:nil];
     ........