plist文件读写

- (void)viewDidLoad{    [super viewDidLoad];        NSDictionary *dictionary1 = [NSDictionary dictionaryWithObjectsAndKeys:@"1",@"a",@"2",@"b", nil];    NSDictionary *dictionary2 = [NSDictionary dictionaryWithObjectsAndKeys:@"3",@"c",@"4",@"d", nil];    // 获取应用程序沙盒的Documents目录    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);    NSString *plistPath = [paths objectAtIndex:0];        // plist文件完整路径    NSString *filename=[plistPath stringByAppendingPathComponent:@"test.plist"];        // *写入(原有数据被覆盖)    [dictionary1 writeToFile:filename atomically:YES];    [dictionary2 writeToFile:filename atomically:YES];        // *读取    NSDictionary *dic = [[NSMutableDictionary alloc] initWithContentsOfFile:filename];    NSLog(@"%@", dic);}

输出结果:

结论:重复对同一plist写入数据，后一次写入的数据将覆盖前一次写入的数据。