如何解析来自 Rest API 的 JSON 响应
How to parse JSON response from Rest API
我正在开发一个应用程序,它将解析来自 Rest API 的数据。因为我以前没有这样做过,所以我想知道 NSScanner 或 NSRange 是否适用于此。下面是一个使用 NSScanner 的例子。这是一个很小的字符串,所以不需要太多代码,所以它看起来像是一个快速而肮脏的选择。有没有更简单快捷的方法来做到这一点?
- (void)GetAliasName:(NSString *)cno selector:(NSString*)selectorName completionHandler:(void (^)(NSDictionary *, NSError *))handler
{
NSMutableDictionary *d = [[NSMutableDictionary alloc] init];
[d setValue:interface forKey:@"interface"];
[d setValue:@"GetAlias" forKey:@"method"];
NSMutableDictionary *p = [[NSMutableDictionary alloc] init];
cno = [[NSUserDefaults standardUserDefaults] objectForKey:@"cno"];
[p setValue:cno forKey:@"cno"];
[p setValue:selectorName forKey:@"selector"];
[d setValue:p forKey:@"parameters"];
NSData *data = [NSJSONSerialization dataWithJSONObject:d options:0 error:nil];
[self load:data completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
NSLog(@"done");
NSString *s = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"GetAlias RAW response = %@", s);
if (apiConditions)
{
dispatch_async(dispatch_get_main_queue(),
^{
[hud hide:YES];
[MBProgressHUD hideHUDForView:self.view animated:YES];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"No network connection or no data found" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
NSLog(@"data is NIL");
});
}
else
{
NSDictionary *d = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
handler(d, error);
//scans for aliasname
NSString *match = @"AliasName\": \"";
NSString *preTel;
NSString *postTel;
NSScanner *scanner = [NSScanner scannerWithString:s];
[scanner scanUpToString:match intoString:&preTel];
[scanner scanString:match intoString:nil];
postTel = [s substringFromIndex:scanner.scanLocation];
//removes newlines, characters, and whitespaces from aliasname
NSCharacterSet *trim = [NSCharacterSet characterSetWithCharactersInString:@"}]\""];
postTel = [[postTel componentsSeparatedByCharactersInSet: trim] componentsJoinedByString: @""];
postTel = [[postTel componentsSeparatedByCharactersInSet: [NSCharacterSet whitespaceAndNewlineCharacterSet]] componentsJoinedByString: @""];
NSLog(@"postTel: %@", postTel);
NSString *docno = [[NSUserDefaults standardUserDefaults] objectForKey:@"docno"];
//if docno is filled in, look up TR by docno
if ([docno isEqual: @""])
{
[self GetTR:(NSString*)postTel customStatus:customStatus completionhandler:^(NSDictionary *dictionary, NSError *error) {
nil;
}];
}
}];
}
有 NSJSONSerialization
是为此而建的。
按如下方式使用:
NSError *error = nil;
NSDictionary *dictionary = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
NSString *aliasName = dictionary[@"AliasName"];
编辑
由于您已经在使用它并拥有字典,因此您唯一需要的步骤就是使用所需的键访问字典(最后一步)。
我正在开发一个应用程序,它将解析来自 Rest API 的数据。因为我以前没有这样做过,所以我想知道 NSScanner 或 NSRange 是否适用于此。下面是一个使用 NSScanner 的例子。这是一个很小的字符串,所以不需要太多代码,所以它看起来像是一个快速而肮脏的选择。有没有更简单快捷的方法来做到这一点?
- (void)GetAliasName:(NSString *)cno selector:(NSString*)selectorName completionHandler:(void (^)(NSDictionary *, NSError *))handler
{
NSMutableDictionary *d = [[NSMutableDictionary alloc] init];
[d setValue:interface forKey:@"interface"];
[d setValue:@"GetAlias" forKey:@"method"];
NSMutableDictionary *p = [[NSMutableDictionary alloc] init];
cno = [[NSUserDefaults standardUserDefaults] objectForKey:@"cno"];
[p setValue:cno forKey:@"cno"];
[p setValue:selectorName forKey:@"selector"];
[d setValue:p forKey:@"parameters"];
NSData *data = [NSJSONSerialization dataWithJSONObject:d options:0 error:nil];
[self load:data completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) {
NSLog(@"done");
NSString *s = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"GetAlias RAW response = %@", s);
if (apiConditions)
{
dispatch_async(dispatch_get_main_queue(),
^{
[hud hide:YES];
[MBProgressHUD hideHUDForView:self.view animated:YES];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"No network connection or no data found" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
NSLog(@"data is NIL");
});
}
else
{
NSDictionary *d = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
handler(d, error);
//scans for aliasname
NSString *match = @"AliasName\": \"";
NSString *preTel;
NSString *postTel;
NSScanner *scanner = [NSScanner scannerWithString:s];
[scanner scanUpToString:match intoString:&preTel];
[scanner scanString:match intoString:nil];
postTel = [s substringFromIndex:scanner.scanLocation];
//removes newlines, characters, and whitespaces from aliasname
NSCharacterSet *trim = [NSCharacterSet characterSetWithCharactersInString:@"}]\""];
postTel = [[postTel componentsSeparatedByCharactersInSet: trim] componentsJoinedByString: @""];
postTel = [[postTel componentsSeparatedByCharactersInSet: [NSCharacterSet whitespaceAndNewlineCharacterSet]] componentsJoinedByString: @""];
NSLog(@"postTel: %@", postTel);
NSString *docno = [[NSUserDefaults standardUserDefaults] objectForKey:@"docno"];
//if docno is filled in, look up TR by docno
if ([docno isEqual: @""])
{
[self GetTR:(NSString*)postTel customStatus:customStatus completionhandler:^(NSDictionary *dictionary, NSError *error) {
nil;
}];
}
}];
}
有 NSJSONSerialization
是为此而建的。
按如下方式使用:
NSError *error = nil;
NSDictionary *dictionary = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
NSString *aliasName = dictionary[@"AliasName"];
编辑
由于您已经在使用它并拥有字典,因此您唯一需要的步骤就是使用所需的键访问字典(最后一步)。