我有一个字典，我需要通过使用字典生成一个JSON字符串。可以转换吗?你们能帮帮我吗?
当前回答
现在不需要第三方类ios 5引入了Nsjsonserialization
NSString *urlString=@"Your url";
NSString *urlUTF8 = [urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url=[[NSURL alloc]initWithString:urlUTF8];
NSURLRequest *request=[NSURLRequest requestWithURL:url];
NSURLResponse *response;
NSData *GETReply = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];
NSError *myError = nil;
NSDictionary *res = [NSJSONSerialization JSONObjectWithData:GETReply options:NSJSONReadingMutableLeaves|| NSJSONReadingMutableContainers error:&myError];
Nslog(@"%@",res);
这段代码对于获取jsondata非常有用。
其他回答
这里有NSArray和NSDictionary的类别，让这个超级简单。我添加了一个漂亮打印的选项(换行符和制表符使阅读更容易)。
@interface NSDictionary (BVJSONString)
-(NSString*) bv_jsonStringWithPrettyPrint:(BOOL) prettyPrint;
@end
.
@implementation NSDictionary (BVJSONString)
-(NSString*) bv_jsonStringWithPrettyPrint:(BOOL) prettyPrint {
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:self
options:(NSJSONWritingOptions) (prettyPrint ? NSJSONWritingPrettyPrinted : 0)
error:&error];
if (! jsonData) {
NSLog(@"%s: error: %@", __func__, error.localizedDescription);
return @"{}";
} else {
return [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
}
}
@end
.
@interface NSArray (BVJSONString)
- (NSString *)bv_jsonStringWithPrettyPrint:(BOOL)prettyPrint;
@end
.
@implementation NSArray (BVJSONString)
-(NSString*) bv_jsonStringWithPrettyPrint:(BOOL) prettyPrint {
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:self
options:(NSJSONWritingOptions) (prettyPrint ? NSJSONWritingPrettyPrinted : 0)
error:&error];
if (! jsonData) {
NSLog(@"%s: error: %@", __func__, error.localizedDescription);
return @"[]";
} else {
return [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
}
}
@end
现在不需要第三方类ios 5引入了Nsjsonserialization
NSString *urlString=@"Your url";
NSString *urlUTF8 = [urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url=[[NSURL alloc]initWithString:urlUTF8];
NSURLRequest *request=[NSURLRequest requestWithURL:url];
NSURLResponse *response;
NSData *GETReply = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];
NSError *myError = nil;
NSDictionary *res = [NSJSONSerialization JSONObjectWithData:GETReply options:NSJSONReadingMutableLeaves|| NSJSONReadingMutableContainers error:&myError];
Nslog(@"%@",res);
这段代码对于获取jsondata非常有用。
注:这个答案是在iOS 5发布之前给出的。
获取json-framework并执行以下操作:
#import "SBJsonWriter.h"
...
SBJsonWriter *jsonWriter = [[SBJsonWriter alloc] init];
NSString *jsonString = [jsonWriter stringWithObject:myDictionary];
[jsonWriter release];
myDictionary就是你的字典。
在Swift中，我创建了以下helper函数:
class func nsobjectToJSON(swiftObject: NSObject) {
var jsonCreationError: NSError?
let jsonData: NSData = NSJSONSerialization.dataWithJSONObject(swiftObject, options: NSJSONWritingOptions.PrettyPrinted, error: &jsonCreationError)!
if jsonCreationError != nil {
println("Errors: \(jsonCreationError)")
}
else {
// everything is fine and we have our json stored as an NSData object. We can convert into NSString
let strJSON : NSString = NSString(data: jsonData, encoding: NSUTF8StringEncoding)!
println("\(strJSON)")
}
}
这是Swift 4的版本
extension NSDictionary{
func toString() throws -> String? {
do {
let data = try JSONSerialization.data(withJSONObject: self, options: .prettyPrinted)
return String(data: data, encoding: .utf8)
}
catch (let error){
throw error
}
}
}
使用的例子
do{
let jsonString = try dic.toString()
}
catch( let error){
print(error.localizedDescription)
}
或者如果你确定它是有效的字典，那么你可以使用
let jsonString = try? dic.toString()
