从argv获取字符 [英] Getting chars from argv

问题描述

该应用程序是Windows 7企业版，MFC，Visual Studio 2008，C ++，启用了unicode



所需的参数是单个字符。 VS配置为提供命令行参数，值为1，argc在添加命令行参数后从1增加到2.

The app is Windows 7 Enterprise, MFC, Visual Studio 2008, C++, unicode enabled

The argument needed is a single character. VS is configured to provide command line argument, value is "1", argc has incremented from 1 to 2 after adding the command line argument.

char str_number = __argv[ 1 ];

编译错误无法从char *转换为char，很酷，理解

Compile error cannot convert from char* to char, cool, understood

char str_number = *__argv[ 1 ];

访问冲突读取位置0x00000004

Access violation reading location 0x00000004

char str_number = *__argv[ 1,0];

访问冲突读取位置0x00000000



我尝试了什么：



我尝试过块中显示的示例：描述问题。

Access violation reading location 0x00000000

What I have tried:

I have tried the examples shown in block: Describe the problem.

推荐答案

在尝试引用任何 __ argc 的值> __ argv 元素。类似于：

You first need to check the value of __argc before attempting to refer to any of the __argv elements. Something like:

if (__argc > 1)
    char str_number = *__argv[ 1 ];

或者您可以使用 CCommandLineInfo类 [ ^ ]。

两者

Both

char str_number = *__argv[1];

和

and

char str_number = __argv[1][0];

应该有效。



请在访问 __ argv 之前，始终检查 __ argc 值，如 Richard 所述。

should work.

Please check always __argc value before accessing __argv, as pointed out by Richard.

当您的应用程序启用了unicode时，您应该使用__wargv而不是__argv。再次尝试你的第二个例子，你应该很幸运。

When your application is unicode enabled you should use __wargv instead of __argv. Try your second example again with that change and you should be in luck.

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