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
苹果在iOS 5.0和Mac OS X 10.7中添加了JSON解析器和序列化器。看到NSJSONSerialization。
要从NSDictionary或NSArray中生成JSON字符串,你不再需要导入任何第三方框架。
以下是如何做到这一点:
NSError *error;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dictionaryOrArrayToOutput
options:NSJSONWritingPrettyPrinted // Pass 0 if you don't care about the readability of the generated string
error:&error];
if (! jsonData) {
NSLog(@"Got an error: %@", error);
} else {
NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
}
其他回答
将NSDictionary转换为NSString:
NSError * err;
NSData * jsonData = [NSJSONSerialization dataWithJSONObject:myDictionary options:0 error:&err];
NSString * myString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
您也可以通过在调试器中输入以下内容即时执行此操作
po [[NSString alloc] initWithData:[NSJSONSerialization dataWithJSONObject:yourDictionary options:1 error:nil] encoding:4];
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()
public func jsonPrint(_ o: NSObject, spacing: String = "", after: String = "", before: String = "") {
let newSpacing = spacing + " "
if o.isArray() {
print(before + "[")
if let a = o as? Array<NSObject> {
for object in a {
jsonPrint(object, spacing: newSpacing, after: object == a.last! ? "" : ",", before: newSpacing)
}
}
print(spacing + "]" + after)
} else {
if o.isDictionary() {
print(before + "{")
if let a = o as? Dictionary<NSObject, NSObject> {
for (key, val) in a {
jsonPrint(val, spacing: newSpacing, after: ",", before: newSpacing + key.description + " = ")
}
}
print(spacing + "}" + after)
} else {
print(before + o.description + after)
}
}
}
这个非常接近最初的Objective-C打印风格
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。