在C和Win32 API中编程：比较字符串 [英] Programming In C and Win32 API: Comparing Strings

问题描述

我在C和Windows API中编写程序。我使用的Visual Studio 2010 Express和字符集设置为未设置。我已经进行了编辑控制来接受用户名。这是声明：

I am writing a program in C and Windows API. I am using Visual Studio 2010 Express and Character Set is set to "Not Set". I have made an edit control to accept username. Here's declaration:

hwnduser = CreateWindow (TEXT("EDIT"), NULL, 
    WS_VISIBLE | WS_CHILD | WS_BORDER,
    220, 70, 80, 20,
    hwnd, (HMENU) 3, NULL, NULL);

我将它的值提取到一个名为username的字符串中。

I am fetching its value into a string named username.

len = GetWindowTextLength(hwnduser) + 1;
GetWindowText(hwnduser, username, len);

现在，有效的用户名位于一个名为c_user的字符串中：

Now, the valid username is in a string called c_user:

char c_user[] = "foo";

当我比较它们以检查用户是否使用以下代码输入了有效的用户名，

When I compare them to check if the user has entered valid username using following code,

if (username == c_user)
{
  MessageBox(hwnd, "Foo", "Bar", MB_OK);
}
else
{
  MessageBox(hwnd, "Bar", "Foo", MB_OK);
}

它从不验证。相反，else条件总是执行！我在哪里犯错误？

It never validates. Instead, the else condition is always executed! Where am I making a mistake?

如何更正？

我试过strcmp！但是，输出不会改变。查看输出（和代码中的比较）：

I have tried strcmp! But still, output does not change. See the output(and comparison in code):

推荐答案

C和C ++没有内置的字符串类型，所以你不能以这种方式比较字符串。 C和C ++代替使用字符数组，这种语法只是比较每个数组的地址（不匹配）。

C and C++ have no built-in string type and so you cannot compare strings this way. C and C++ instead use an array of chars and this syntax simply compares the address of each array (which won't match).

而是使用 strcmp（）或 _tcscmp（）。

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