将复杂结构传递给Windows API
将复杂结构传递给Windows API
提问于 2019-08-22 05:20:28
我正在尝试通过Perl6和(当然) NativeCall从Windows API中使用GetConsoleScreenBufferInfo(HANDLE, PCONSOLE_SCREEN_BUFFER_INFO)函数。
我想我已经正确地设置了函数所需的CONSOLE_SCREEN_BUFFER_INFO结构，但是当我尝试转储其内容时，代码在调用后崩溃。
这是演示问题的最短(不完全但很接近)的方法：
use NativeCall;
constant \HANDLE := Pointer[void];
constant \SHORT := int16;
constant \USHORT := uint16;
constant \WORD := uint16;
constant \DWORD := uint32;
constant \BOOL := int32;
constant \STD_OUTPUT_HANDLE := -11;
constant \STD_INPUT_HANDLE := -10;
class COORD is repr('CStruct') {
has SHORT $.X;
has SHORT $.Y;
}
class SMALL_RECT is repr("CStruct") {
has SHORT $.Left;
has SHORT $.Top;
has SHORT $.Right;
has SHORT $.Bottom;
};
class CONSOLE_SCREEN_BUFFER_INFO is repr("CStruct") {
has COORD $.dwSize;
has COORD $.dwCursorPosition;
has WORD $.wAttributes;
has SMALL_RECT $.srWindow;
has COORD $.dwMaximumWindowSize;
submethod TWEAK {
$!dwSize := COORD.new;
$!dwCursorPosition := COORD.new;
$!srWindow := SMALL_RECT.new;
$!dwMaximumWindowSize := COORD.new;
}
}
# C: BOOL WINAPI GetConsoleScreenBufferInfo(_In_ HANDLE hConsoleOutput, _Out_ PCONSOLE_SCREEN_BUFFER_INFO lpConsoleScreenBufferInfo);
sub GetConsoleScreenBufferInfo(HANDLE, CONSOLE_SCREEN_BUFFER_INFO is rw) is native("Kernel32.dll") returns BOOL { * };
sub GetStdHandle(DWORD) is native('Kernel32') returns Pointer[void] { * };
my CONSOLE_SCREEN_BUFFER_INFO
$info = CONSOLE_SCREEN_BUFFER_INFO.new;
my HANDLE
$handle-o = GetStdHandle( STD_OUTPUT_HANDLE );
dd $info;
say "GetConsoleScreenBufferInfo ", GetConsoleScreenBufferInfo( $handle-o, $info );
say "Will I live?";
dd $info; #crashes without notice任何关于崩溃发生的原因以及如何修复它的提示都是非常受欢迎的。
回答 1
Stack Overflow用户
回答已采纳
发布于 2019-08-23 04:10:35
对于作为结构的CONSOLE_SCREEN_BUFFER_INFO的成员，您需要使用HAS而不是has，因为这些成员是嵌入的，而不是由指针引用的(这是Perl6的默认设置)。
完成此操作后，还可以删除TWEAK，这样代码就会显示为
class CONSOLE_SCREEN_BUFFER_INFO is repr("CStruct") {
HAS COORD $.dwSize;
HAS COORD $.dwCursorPosition;
has WORD $.wAttributes;
HAS SMALL_RECT $.srWindow;
HAS COORD $.dwMaximumWindowSize;
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/57599297
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