在MFC中使dialog自适应缩放

起因

最近用mfc做了不少小软件，界面上都是基于CDialog或者CFormView，界面不能缩放一直是问题。一个办法是在OnSize()里面调用所有控件的MoveWindow()函数，根据比例调整控件大小。但是在界面上控件比较多的时候，这个发放就显得很繁琐了。于是我写了一个CAutoResize类，去实现控件的统一缩放。

工作原理

原理上很简单，对于MFC中的CDilalog，它的信息都存在程序文件夹下的XXX.rc中，XXX是项目名称。如下图所示，

CAutoResize类首先就读取XXX.rc，先获取控件长宽信息，dlgWidth和dlgHeight。然后获取相应控件上的ID，x和y坐标，控件宽度和高度，用这些值去除以dlgWidth和dlgHeight得到相应的比例，然后把信息存在Vector数组中。

Init函数

bool CAutoResize::Init(char *resourceName, char *dlgID)
{
    CString strRcName;
    CString strDlgID;
    strDlgID.Format("%s", dlgID);
    strRcName.Format("./%s", resourceName);

    if(!rcFile.Open(strRcName, CFile::modeRead))
    {
        AfxMessageBox("can't open the resource file");
    }
    CString strRead;

//找到dlgID所在的行

    while(rcFile.ReadString(strRead))
    {
        TRACE("strRead:%s
", strRead);

        if(!Match(strRead, strDlgID))
        {
            continue;
        }
        else 
        {   
            int commaIndex = strRead.Find(",");
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
            dlgWidth = atoi((const char*)strRead.Left(commaIndex));
            strRead = strRead.Mid(commaIndex + 1);
            dlgHeight = atoi((const char*)strRead);
            TRACE("dlgWidth:%d
dlgHeight:%d
", dlgWidth, dlgHeight);


            for(int i=0;i<3;i++)
            {
                rcFile.ReadString(strRead);

            }
            break;
        }
    }


    // 开始读取各个控件的信息
    while(rcFile.ReadString(strRead))
    {
        Item item;  


        TRACE("strRead:%s
", strRead);
        if(strRead == "END")
        {
            break;
        }
        CString str = strRead.Left(20);
        str.TrimLeft(" ");
        str.TrimRight(" ");
        TRACE("begin to store items
");
        strRead = strRead.Mid(20);
        strRead.TrimLeft(" ");


        CString tempRead, strTemp;
        tempRead.Empty();
        strTemp.Empty();
        long pos;

        do 
        {
        tempRead.TrimLeft(" ");
        strRead = strRead + tempRead;
         pos = rcFile.GetPosition();

        rcFile.ReadString(tempRead);
        TRACE("tempRead:%s
", tempRead);
        strTemp = tempRead.Left(20);
        strTemp.TrimLeft(" ");
        strTemp.TrimRight(" ");

        TRACE("strTemp:%s
", strTemp);

        }while(strTemp.IsEmpty());


        rcFile.Seek(pos, CFile::begin);

        TRACE("strRead:%s
", strRead);     

        TRACE("str:%s
", str);

//不同的控件类型格式不同，分情况讨论
//  format: ID, x, y, width, height, style
        if(str == _T("EDITTEXT") || str == _T("COMBOBOX"))   
        {
            int commaIndex = strRead.Find(",");
 //存储控件id 类型CString, 过会还要读取resource.h去获取对应的Int类型id
            item.itemID = strRead.Left(commaIndex);              
            TRACE("itemID:%s
", strRead.Left(commaIndex));
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
 // 坐标x比例

            item.xPercentage = (float)atoi((const char *)strRead.Left(commaIndex)) / (float)dlgWidth;  
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
// 坐标y比例
            item.yPercentage = (float)atoi((const char *)strRead.Left(commaIndex)) / (float)dlgHeight; 
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
// 宽比例
            item.widthPercentage = (float)atoi((const char *)strRead.Left(commaIndex)) / (float)dlgWidth;  
            strRead = strRead.Mid(commaIndex + 1);
//高比例
            item.heightPercentage = (float)atoi((const char *)strRead) / (float)dlgHeight;          


        }      
 // format: text, id, class, style, x, y, width, height
        else if(str == _T("CONTROL"))                     
        {
            int commaIndex = strRead.Find(",");
            strRead = strRead.Mid(commaIndex + 1);          
            commaIndex = strRead.Find(",");
            item.itemID = strRead.Left(commaIndex);
            TRACE("itemID:%s
", strRead.Left(commaIndex));
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
            item.xPercentage = (float)atoi((const char *)strRead.Left(commaIndex)) / (float)dlgWidth;

            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
            item.yPercentage = (float)atoi((const char *)strRead.Left(commaIndex)) / (float)dlgHeight;
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
            item.widthPercentage = (float)atoi((const char *)strRead.Left(commaIndex)) / (float)dlgWidth;
            strRead = strRead.Mid(commaIndex + 1);

            item.heightPercentage = (float)atoi((const char *)strRead) / (float)dlgHeight;



        }       
// format :text, id, x, y, width, height
        else                                                           
        {
            TRACE("others
");
            int commaIndex = strRead.Find(",");
            strRead = strRead.Mid(commaIndex + 1);      
            commaIndex = strRead.Find(",");
            item.itemID = strRead.Left(commaIndex);
            TRACE("itemID:%s
", strRead.Left(commaIndex));
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
            item.xPercentage = (float)atoi((const char *)strRead.Left(commaIndex)) / (float)dlgWidth;

            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
            item.yPercentage = (float)atoi((const char *)strRead.Left(commaIndex)) / (float)dlgHeight;
            strRead = strRead.Mid(commaIndex + 1);
            commaIndex = strRead.Find(",");
            item.widthPercentage = (float)atoi((const char *)strRead.Left(commaIndex)) / (float)dlgWidth;
            strRead = strRead.Mid(commaIndex + 1);

            item.heightPercentage = (float)atoi((const char *)strRead) / (float)dlgHeight;




        }   

        TRACE("%s %f %f %f %f
", item.itemID, item.xPercentage, item.yPercentage, item.widthPercentage, item.heightPercentage);
        itemVec.push_back(item);
        TRACE("num of cotrol object is :%d", itemVec.size());

    }

    return true;
}

GetIdFromString函数，读取resource.h获取对应Int类型id。

int CAutoResize::GetIdFromString(CString &str)   // Convert the type of control's ID from string to int.
{

    CStdioFile file;
    int len = str.GetLength();
    if(!file.Open(_T("./resource.h"), CFile::modeRead)) // read the resource file
    {
        AfxMessageBox(_T("resource file open failed"));
        return 0;
    }
    CString strRead;
    while(file.ReadString(strRead))
    {
        if(!strRead.IsEmpty())
        {
            if(strRead.Left(2) == "#d")
            {   
                strRead = strRead.Mid(8);
                int commaIndex = strRead.Find(" ");

                if(strRead.Left(commaIndex) == str)                     
                {
                    strRead = strRead.Mid(commaIndex+1);
                    strRead.TrimLeft(" ");
                    TRACE("%s
", strRead);
                    return atoi((const char*)strRead);   // get  item id;
                }
            }
        }
    }
    return 0;
}

Resize函数 改变控件大小

void CAutoResize::Resize(CView *pView, int cx, int cy)
{

    //从vector中取出每个控件信息
    std::vector<Item>::iterator iter;
    for(iter = itemVec.begin(); iter != itemVec.end();++iter)  
    {   
        Item *item = static_cast<Item*>(iter);
        int x = item->xPercentage*cx;
        int y = item->yPercentage*cy;
        int width = item->widthPercentage*cx;
        int height = item->heightPercentage*cy;
        CRect rc;
        rc.SetRect(x, y, x+width, y+height);
        TRACE("cotrol name:%s
", item->itemID);
        TRACE("	 x:%d, y:%d,  %d, height:%d
", x, y, width, height);
        int id = GetIdFromString(item->itemID);

        // MoveWindow

        if(id)
        {       
        (pView->GetDlgItem(id))->MoveWindow(&rc);
        }
    }
}

使用方法

1.在CDialog类中加入CAutoSize类的成员变量

2.在对话框的初始化函数中调用Init函数，传入资源文件名和对话框id

3.在OnSize（）中调用Resize函数。

注：对话框中必须给每个CStatic控件不同的id，不然就不能改变大小。

不足之处

1.一些控件类型格式不同，目前init函数里所测试过的格式不多，不排除有一些格式读不出来。所以这个类只是提供一种方法，并不通用。

2.由于运行时需要读取XXX.rc和resource.h文件，所以在生成的exe运行文件文件夹下也必须要有这两个文件。