How to represent general binary data

最新推荐文章于 2025-01-13 15:16:10 发布

原创最新推荐文章于 2025-01-13 15:16:10 发布 · 792 阅读

1 ·

CC 4.0 BY-SA版权

文章标签：

#descriptor #buffer #constructor #arrays #wrapper #symbian

Symbian 专栏收录该内容

62 篇文章

订阅专栏

本文档介绍了Symbian S60系统中如何使用8位变体描述符处理普通二进制数据的方法。描述符不仅能够处理文本数据，还可以灵活地处理各种二进制数据。通过示例代码展示了初始化内存区域中的二进制数据，并将其添加到描述符中，同时可以混合文本和二进制数据。

下面的内容摘自Symbian S60 3rd Edition SDK，先把英文原版贴在这里，等时间充足的时候我再把它翻译出来。How to represent general binary data《如何表示普通的二进制数据》

How to represent general binary data

The kind of data represented or contained by descriptors is not restricted to text. Descriptors can also handle general binary data.

To deal with general binary data, always explicitly construct an 8 bit variant descriptor. Binary data should always be treated as 8 bit data regardless of the build.

For example, starting with an area in memory initialised with binary data as follows:

TUint8 data[6] = {0x00,0x01,0x02,0xAD,0xAE,0xAF};

construct a modifiable buffer descriptor using the default constructor as follows:

TBuf8<32> buffer;

The following code fragment puts the binary data into the descriptor and appends a number of single byte values. The length of the buffer is 9, the maximum length is 32 and the size is 9 regardless of the build.

TInt index; TInt counter;

Text and general binary data can be freely mixed and the following code is acceptable:

buffer.Append('A'); buffer.Append('B'); buffer.Append(0x11);

Note that fixed length C++ arrays such as data above can be packaged inside a thin wrapper class, a TFixedArray<class T,TInt S> type, to guarantee that all array accesses are safe.