richedit设置滚动条的位置和更新内容

全栈程序员-站长 • 2022年1月13日下午10:00 • 未分类 • 阅读 84

大家好，又见面了，我是全栈君，今天给大家准备了Idea注册码。

需要txt发现读者richedit的scrollbar位置（为了便于下一次读，直接访问与上次读取下一个读取位置）不值得治疗，采用GetScrollPos、SetScrollPos你可以设置scorllbar位置值。可是！

SetScorllPos调用后仅仅更新了scorllbar的位置richedit的内容没得到更新，google一下没有个现成的解决。仅仅得msdn。

WM_VSCROLL重点标记一下：

SB_THUMBPOSITION

The user has dragged the scroll box (thumb) and released the mouse button. The HIWORD indicates the position of the scroll box at the end of the drag operation.

However, because the
SetScrollInfo
,
SetScrollPos
,
SetScrollRange
,
GetScrollInfo
,
GetScrollPos
, and
GetScrollRange
functions support 32-bit scroll bar position data, there is a way to circumvent the 16-bit barrier of the
WM_HSCROLL
and
WM_VSCROLL
messages. See
GetScrollInfo
for a description of the technique.

GetScrollInfo重点标记一下：

SIF_TRACKPOS

Copies the current scroll box tracking position to the nTrackPosmember of the SCROLLINFO structure pointed to by lpsi.

Remarks

The GetScrollInfo function enables applications to use 32-bit scroll positions. Although the messages that indicate scroll bar position, WM_HSCROLL and WM_VSCROLL, provide only 16 bits of position data, the functions SetScrollInfo and GetScrollInfo provide 32 bits of scroll bar position data. Thus, an application can call GetScrollInfo while processing either theWM_HSCROLL or WM_VSCROLL messages to obtain 32-bit scroll bar position data.

To get the 32-bit position of the scroll box (thumb) during a SB_THUMBTRACK request code in a WM_HSCROLL or WM_VSCROLL message, call GetScrollInfo with the SIF_TRACKPOS value in the fMask member of the SCROLLINFO structure. The function returns the tracking position of the scroll box in the nTrackPos member of the SCROLLINFO structure. This allows you to get the position of the scroll box as the user moves it. The following sample code illustrates the technique.

SCROLLINFO si; case WM_HSCROLL: switch(LOWORD(wparam)) { case SB_THUMBTRACK: // Initialize SCROLLINFO structure ZeroMemory(&si, sizeof(si)); si.cbSize = sizeof(si); si.fMask = SIF_TRACKPOS; // Call GetScrollInfo to get current tracking // position in si.nTrackPos if (!GetScrollInfo(hwnd, SB_HORZ, &si) ) return 1; // GetScrollInfo failed break; . . . }

实现本文功能：

//保存scrollbar位置
  SCROLLINFO Info={0};
  Info.cbSize=sizeof Info;
  Info.fMask=SIF_TRACKPOS;
  GetScrollInfo(RichEdit1->Handle,SB_VERT,&Info);
  std::auto_ptr<TIniFile> ptrIni(new TIniFile(ExtractFilePath(Application->ExeName)+"Config"));
  ptrIni->WriteInteger("Reader","ScorllPos",Info.nTrackPos);




//设置scrollbar位置
    std::auto_ptr<TIniFile> ptrIni(new TIniFile(ExtractFilePath(Application->ExeName)+"Config"));
    int pos=ptrIni->ReadInteger("Reader","ScorllPos",0);
    SendMessage(RichEdit1->Handle,WM_VSCROLL,MAKEWPARAM(SB_THUMBPOSITION,pos),0);

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