1丶 讀

//建立檔案管理器

NSFileManager *fileManager = [NSFileManagerdefaultManager];

NSArray *pathA = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);

    NSString *documentation = [pathA   objectAtIndex:0];

//更改到待操作的目錄下

    [fileManager changeCurrentDirectoryPath:[documentation

    NSString *path = [documentation   stringByAppendingPathComponent:@"citys.plist"];

  //讀取的陣列

   NSArray * array=[[NSArray alloc] initWithContentsOfFile:path];

2丶寫

 //獲取路徑物件

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    //獲取完整路徑

    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSString *plistPath = [documentsDirectory stringByAppendingPathComponent:@"citys.plist"];

//DataArray 就是寫入的陣列

[DataArray writeToFile:plistPath atomically:YES];