C 语言 学习---ComboBox相关、简单计算器

BOOL Main_OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam)
{
    //当会话框初始化的时候被调用
	HWND hwndCombo1 = GetDlgItem(hwnd,IDC_COMBOOP);
	/*
	怎样使字符串加入的顺序不变?
	ComboBox_AddString(hwndCombo1,TEXT("+"));
	ComboBox_AddString(hwndCombo1,TEXT("-"));
	ComboBox_AddString(hwndCombo1,TEXT("*"));
	ComboBox_AddString(hwndCombo1,TEXT("/"));
	*/
	ComboBox_InsertString(hwndCombo1,-1,TEXT("+"));
	ComboBox_InsertString(hwndCombo1,-1,TEXT("-"));
	ComboBox_InsertString(hwndCombo1,-1,TEXT("*"));
	ComboBox_InsertString(hwndCombo1,-1,TEXT("/"));
	return TRUE;
}

 

 

void Main_OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify)
{
    switch(id)
    {
        case IDC_OK:
		{
			//HWND hwndCombo1 = GetDlgItem(hwnd,IDC_COMBO1);
			/*确定目前选项的索引
			int curSel = ComboBox_GetCurSel(hwndCombo1);
			if(0==curSel)
			{
				MessageBox(hwnd,TEXT("你选择的是-号"),TEXT("消息"),MB_OK);
			}
			*/
			/*删除其中的一个选项
			ComboBox_DeleteString(hwndCombo1,2);
			选定某一项
			ComboBox_SetCurSel(hwndCombo1,2);
			*/
			/*得到某项的值
			TCHAR str[256];
			ComboBox_GetLBText(hwndCombo1,1,str);
			MessageBox(hwnd,str, TEXT("消息"),MB_OK);
			*/
			TCHAR str1[256];
			TCHAR str2[256];
			GetDlgItemText(hwnd,IDC_EDIT1,str1,sizeof(str1));
			GetDlgItemText(hwnd,IDC_EDIT2,str2,sizeof(str2));
			int i1 = atoi(str1);
			int i2 = atoi(str2);
			int i3 = 0;
			HWND hwndComboOp = GetDlgItem(hwnd,IDC_COMBOOP);
			int curIndex = ComboBox_GetCurSel(hwndComboOp);
			switch(curIndex)
			{
				case 0:
					{
						i3 = i1+i2;
					}
					break;
				case 1:
					{
						i3 = i1-i2;
					}
					break;
				case 2:
					{
						i3 = i1*i2;
					}
					break;
				case 3:
					{
						i3 = i1/i2;
					}
					break;
			}
			TCHAR str3[256];
			itoa(i3,str3,10);
			SetDlgItemText(hwnd,IDC_EDIT3,str3);
		}
        break;
        default:
		break;
    }
}