// 1.读取沙盒中plist文件

     // 1.1.获得沙盒根路径

     NSString *home = NSHomeDirectory();

     // 1.2.拼接Documents路径

     NSString *docPath = [home stringByAppendingPathComponent:@"Documents"];

     // 1.3.文件的全路径

     NSString *filepath = [docPath stringByAppendingPathComponent:@"login.plist"];

     // 2.从plist中加载一个字典出来

     NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:filepath];

     // 3.赋值

     self.userName.text = dict[@"qq"];

     self.passWord.text = dict[@"pwd"];

 NSDictionary *dict = @{

                            @"qq" : self.userName.text,

                            @"pwd" : self.userName.text

                            };

     // 2.存储数据到沙盒的plist文件中

     // 2.1.获得沙盒根路径

     NSString *home = NSHomeDirectory();

     // 2.2.拼接Documents路径

     NSString *docPath = [home stringByAppendingPathComponent:@"Documents"];

     // 2.3.文件的全路径

     NSString *filepath = [docPath stringByAppendingPathComponent:@"login.plist"];

     [dict writeToFile:filepath atomically:YES];