iphone 读写配置文件

-(void) writeConfigFile:(NSData *)data fromFile:(NSString*)strFile 
{
    //Create File Manager
    NSFileManager *fileManager = [NSFileManager defaultManager];
    //获取路径
    //参数NSDocumentDirectory要获取那种路径
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
//去处需要的路径   
    NSString *documentsDirectory = [paths objectAtIndex:0];
    //更改到待操作的目录下
    [fileManager changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]];
    
//移除本文件管理器下的该项
    //[fileManager removeItemAtPath:strFile error:nil];

//获取文件路径
    NSString *path = [documentsDirectory stringByAppendingPathComponent:strFile];

    //判断文件是否存在  
    if (![[NSFileManager defaultManager] fileExistsAtPath:path]) 
{ 
        [fileManager createFileAtPath:path contents:data attributes:nil];    
    }    
}


-(NSMutableDictionary*) readConfigFile:(NSString*)file
{  
    //Create File Manager
    NSFileManager *fileManager = [NSFileManager defaultManager];
    //获取路径
    //参数NSDocumentDirectory要获取那种路径
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];//去处需要的路径
    
    //更改到待操作的目录下
    [fileManager changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]];
    
    //获取文件路径
    NSString *path = [documentsDirectory stringByAppendingPathComponent:file];
      
    NSMutableDictionary *dict=[[NSMutableDictionary alloc] initWithContentsOfFile:path];
    
   return dict;  
}  


-(void) SetValueByKey:(NSString *)value modifyByValue:(NSString*)key fromFile:(NSString*)file
{  
    //Create File Manager
    NSFileManager *fileManager = [NSFileManager defaultManager];
    //获取路径
    //参数NSDocumentDirectory要获取那种路径
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];//去处需要的路径
    
    //更改到待操作的目录下
    [fileManager changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]];
    
    //获取文件路径
    NSString *path = [documentsDirectory stringByAppendingPathComponent:file];
    
    NSMutableDictionary *dict=[[NSMutableDictionary alloc] initWithContentsOfFile:path];
    [dict setObject:value forKey:key];//通过key来修改value
    NSData *data=[[NSData alloc] init];
    data=dict;
    [fileManager removeItemAtPath:@"config" error:nil];
    [fileManager createFileAtPath:path contents:data attributes:nil];
    [data release];    
}


-(NSString*)getValueByKey:(NSString*)key fromFile:(NSString*)file
{  
    //Create File Manager
    NSFileManager *fileManager = [NSFileManager defaultManager];
    //获取路径
    //参数NSDocumentDirectory要获取那种路径
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];//去处需要的路径
    
    //更改到待操作的目录下
    [fileManager changeCurrentDirectoryPath:[documentsDirectory stringByExpandingTildeInPath]];
    
    //获取文件路径
    NSString *path = [documentsDirectory stringByAppendingPathComponent:file];
      
    NSMutableDictionary *dict=[[NSMutableDictionary alloc] initWithContentsOfFile:path];
    
    NSString *object=[dict objectForKey:key];  
    if (object==nil || object.length==0)
{  
                 object=@"0";  
    }  
    return object;  
}