c++ - Windows API SendMessage + WM_SETTEXT导致崩溃

我在使用SendMessageA(handle，WM_SETTEXT，0，(LPARAM)text)时遇到麻烦；如果在构造函数以外的其他地方使用它，则会导致崩溃。

MWC.h

#include <Windows.h>
#include <iostream>
#include <string>

class MWC{
private:
    MSG msg;
public:
    MWC();
    ~MWC();
    int mLoop();
    int mClose(UINT);
    class System{
    public:
        System(){ }
        ~System(){ }
        class Form{
        public:
            HWND handle; // Need to access it in order to create other controls
            Form(char*,int,int,int,int);
            Form(char*,int,int);
            ~Form(){ }
            bool Show();
            HWND ReturnHandle();
        };
        class TextBox{
        protected:
            HWND handle;
        private:
            int ID;
        public:
            TextBox(char* text,int width,int height,int x,int y,int id,Form* p);
            TextBox(int width,int height,int x,int y,int id,Form* p);
            ~TextBox(){ }
            bool IsChanged(UINT,WPARAM);
            bool Text(char *);
            int GetId(){ return ID; }
        };

        class messageBox{
        public:
            messageBox(){ };
            ~messageBox(){ };
            bool Show(LPCWSTR,LPCWSTR,UINT);
            bool ShowA(char*,char*,UINT);
            bool ShowA(std::string,std::string,UINT);
        };
    };
};

MWC.cpp

#include "MWC.h"

MWC::MWC(){ }
MWC::~MWC(){ }
int MWC::mLoop(){
    while(GetMessage(&msg,NULL,0,0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 1;
}
int MWC::mClose(UINT _msg){
    if(_msg == WM_CLOSE){PostQuitMessage(0);return 1;}
    return 0;
}
MWC::System::Form::Form(char* Title,int width,int height,int x,int y){
    handle =  CreateWindowEx(0,WC_DIALOG,Title,WS_OVERLAPPEDWINDOW | WS_VISIBLE,x,y,width,height,NULL,NULL,NULL,NULL);
}
MWC::System::Form::Form(char* Title,int width,int height){
    handle =  CreateWindowEx(0,WC_DIALOG,Title,WS_OVERLAPPEDWINDOW | WS_VISIBLE,400,100,width,height,NULL,NULL,NULL,NULL);
}

bool MWC::System::Form::Show(){
    return false;
}

HWND MWC::System::Form::ReturnHandle(){
    return handle;
}

MWC::System::TextBox::TextBox(char* text,int width,int height,int x,int y,int id,Form* p){
    ID = id;
    handle = CreateWindowEx(WS_EX_CLIENTEDGE,"EDIT",text,WS_VISIBLE | WS_CHILD,x,y,width,height,p->handle,(HMENU)id,NULL,NULL);
}
MWC::System::TextBox::TextBox(int width,int height,int x,int y,int id,Form* p){
    ID = id;
    handle = CreateWindowEx(WS_EX_CLIENTEDGE,"EDIT","",WS_VISIBLE | WS_CHILD,x,y,width,height,p->handle,(HMENU)id,NULL,NULL);
    SendMessageA(handle,WM_SETTEXT,0,(LPARAM)"It works here!");
}
bool MWC::System::TextBox::IsChanged(UINT message, WPARAM wParam){
    if(message==WM_COMMAND && HIWORD(wParam)==EN_CHANGE && LOWORD(wParam)==ID){
        return true;
    }
    return false;
}

bool MWC::System::TextBox::Text(char* text){
    if(handle == NULL){
        return 0;
    }
    else{
        //SendMessageA(handle,WM_SETTEXT,0,(LPARAM)text); // It doesn't work here!
        return 1;
    }
    return 1;
}


bool MWC::System::messageBox::Show(LPCWSTR text,LPCWSTR caption,UINT id){
    ::MessageBoxW(NULL,text,caption,id);
    return true;
}

bool MWC::System::messageBox::ShowA(char* text,char* caption,UINT id){
    ::MessageBoxA(NULL,(LPCSTR)text,(LPCSTR)caption,id);
    return true;
}

bool MWC::System::messageBox::ShowA(std::string text,std::string caption,UINT id){
    ::MessageBoxA(NULL,(LPCSTR)text.c_str(),(LPCSTR)caption.c_str(),id);
    return true;
}

Main.cpp

#include "MWC.h"

MWC mwc = MWC();
MWC::System::messageBox mbox = MWC::System::messageBox();
MWC::System::Form form1 = MWC::System::Form("Window",600,600);
MWC::System::TextBox textbox1 = MWC::System::TextBox(600,500,0,0,156,&form1);

BOOL WINAPI myProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    mwc.mClose(message);

    //check if text in textbox has been changed by user
    textbox1.Text("Test");
    if(textbox1.IsChanged(message,wParam) == true){

    }
    return false;
}





int APIENTRY WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
    SetWindowLong(form1.ReturnHandle(), DWL_DLGPROC, (long)myProc); // to be added in the class
    mwc.mLoop();
    return 0;
}

这个东西是.. sendmessage在(MWC.cpp)上工作正常:

MWC::System::TextBox::TextBox(int width,int height,int x,int y,int id,Form* p){
    ID = id;
    handle = CreateWindowEx(WS_EX_CLIENTEDGE,"EDIT","",WS_VISIBLE | WS_CHILD,x,y,width,height,p->handle,(HMENU)id,NULL,NULL);
    SendMessageA(handle,WM_SETTEXT,0,(LPARAM)"It works here!"); // TESTING
}

但如果在此处使用，则会导致崩溃:

bool MWC::System::TextBox::Text(char* text){
    if(handle == NULL){
        return 0;
    }
    else{
        //SendMessageA(handle,WM_SETTEXT,0,(LPARAM)text); // It doesn't work here!
        return 1;
    }
    return 0;
}

顺便说一句，我只是一个与winapi混为一谈的业余爱好者。随时对您偶然发现的任何错误发表评论!

最佳答案

您的对话框过程看起来不对。您正在尝试每次对话过程运行一次发送WM_SETTEXT!这可能设置了无限递归，可能还设置了其他各种问题。

您的SendMessage调用绝对好，每次对话过程运行时您都无法做到。

我不明白IsChanged()函数的全部含义。您的框架设计非常奇怪。我建议您先看看其他一些框架(例如ATL)，以获取有关如何围绕Win32编写框架的一些想法。或者，甚至更好的是，使用现有框架。