在LPCSTR中追加BSTR [英] Appending BSTR in a LPCSTR

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本文介绍了在LPCSTR中追加BSTR的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我有一个类函数接收一个BSTR。在我的类中,我有一个成员变量是LPCSTR。现在我需要附加BSTR ins LPCSTR。我怎么能这样做。
这是我的函数。

I have a class function which is receving a BSTR. In my class I have a member variable which is LPCSTR. Now I need to append BSTR ins LPCSTR. How I can do that. Here is my function.

void MyClass::MyFunction(BSTR text)
{
    LPCSTR name = "Name: ";
    m_classMember = name + text; // m_classMember is LPCSTR.
}

在我的m_classMember中我希望这个函数值后应该是Name:text_received_in_function 。

in my m_classMember I want that after this function value should be "Name: text_received_in_function". How i can do that.

推荐答案

使用Microsoft特定的 _bstr_t 类,本机。像

Use the Microsoft specific _bstr_t class, which handles the ANSI/Unicode natively. Something like

#include <comutils.h>
// ...

void MyClass::MyFunction(BSTR text)
{
    _bstr_t name = "Name: " + _bstr_t(text, true);
    m_classMember = (LPCSTR)name;
}

是你几乎想要的。然而,正如注释中所指出的,你必须管理 m_classMember 和连接的字符串的生命周期。在上面的例子中,代码可能会崩溃。

is what you almost want. However, as pointed out by the remarks, you have to manage the lifetime of m_classMember and the concatened string. In the example above, the code is likely to crash.

如果你拥有 MyClass 添加另一个成员变量:

If you own the MyClass object, you could simply add another member variable:

class MyClass {
private:
  _bstr_t m_concatened;
//...
};

,然后使用 m_classMember m_concatened 的字符串内容。

and then use m_classMember as a pointer to the string content of m_concatened.

void MyClass::MyFunction(BSTR text)
{
    m_concatened = "Name: " + _bstr_t(text, true);
    m_classMember = (LPCSTR)m_concatened;
}

否则,在分配 m_classMember ,你应该以与分配它相同的方式释放它( free delete [] 等等),并创建一个新的 char * 数组,在其中复制连接字符串的内容。类似

Otherwise, prior to the assignment of m_classMember, you should free it in the same way you allocated it (free, delete [], etc), and create a new char* array in which you copy the content of the concatened string. Something like

void MyClass::MyFunction(BSTR text)
{
    _bstr_t name = "Name: " + _bstr_t(text, true);

    // in case it was previously allocated with 'new'
    // should be initialized to 0 in the constructor
    delete [] m_classMember; 
    m_classMember = new char[name.length() + 1];

    strcpy_s(m_classMember, name.length(), (LPCSTR)name);
    m_classMember[name.length()] = 0;
}

应该做这项工作。

这篇关于在LPCSTR中追加BSTR的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!

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