How IOS can read and write JSON files with Jsonkit

how to read and write JSON files with JsonkitCategory: iOS2013-04-20 12:46510 people readComments (0)CollectionReport

JSON file format is simple, easy to use, worth a use.

At present, there are many libraries to support the parsing of JSON files, in this, Jsonkit easy to use and high efficiency, this article is about the use of Jsonkit.

1. Preparatory work

Download Jsonkit Package: http://download.csdn.net/detail/enuola/4523160

2. Write JSON file

• Create a file

Create file directory and file, need to use FileManager

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2. Nsarray *paths = Nssearchpathfordirectoriesindomains (NSDocumentDirectory, Nsuserdomainmask, YES);
3. NSString *documentsdirectory = [Paths objectatindex:0];
4. Testdirectory = [documentsdirectory stringbyappendingpathcomponent:@ "Data"];
5. [FileManager createdirectoryatpath:testdirectory withintermediatedirectories:yes Attributes:nil Error:nil];
6. Letterllkpath = [testdirectory stringbyappendingpathcomponent:@ "Letterllk.json"];

• Open file ready to write

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1. Open file, need to use Nsfilehandle
2. Nsfilehandle *letterhandle = [Nsfilehandle Filehandleforwritingatpath:letterllkpath];

• Converting content to JSON data

The following data type conversions are supported in Jsonkit:

• NSString
• Nsarry
• Nsdictionary

It 's easy to use: [Plain]View Plaincopy

2. Raw data
4. NSString *str = ....;
6. Nsarry *arry = ....;
8. Nsdictionary *dic = ...;
12. Converting to a JSON string is the packaging of the raw data
14. NSString *strjson = [str jsonstring];
16. NSString *arryjson = [Arry jsonstring];
18. NSString *dicjson = [dic jsonstring];
22. or switch directly to nsdata*.
24. NSData *strdata = [str jsondata];
26. NSData *arrydata = [Arry jsondata];
28. NSData *dicdata = [dic jsondata];

• Writes the converted JSON data to the text

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1. [Letterhandle Seektoendoffile];
2. [Letterhandle Writedata:[strjson datausingencoding:nsutf8stringencoding];
3. Or
4. [Letterhandle Writedata:strdata];

3. Read the JSON file

• Read File contents

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1. NSString *filepath = [[NSBundle mainbundle] pathforresource:@ "test" oftype:@ "JSON"];
2. NSString *jsonstring = [NSString stringwithcontentsoffile:filepath encoding:nsutf8stringencoding Error:nil];

• Parsing content with JSON

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1. //Based on a JSON file, parse    by layer;
2. nserror  *error;  
3. id rawdata = [jsonstring  objectfromjsonstringwithparseoptions:jkparseoptionnone error:&error];  
4.   
5. if  ( error != nil )  {  
6. }   
7.   
8. if  ( [rawData  iskindofclass:[nsdictionary class]] )    
9. {}   
10. else if  ( [rawData isKindOfClass:[NSArray class]] )  {  
11. }  
12. else {   
13. }  

4. Summary

The encoding format of JSON mainly includes:

• [] represents the Nsarry class
• {} represents an object, such as Nsdictionary
• , representing the object delimiter
• : Represents a key-value pair, or can be understood as an assignment =

Jsonkit actually automatically helps you to add the original data to these symbols, or, conversely, to remove the symbols