BCB 中测量Richedit 的文本总行高

系统管理员 2024-02-19 19:24 17阅读 0赞

## [BCB 中测量Richedit 的文本总行高][BCB _Richedit] ##

1，需要使用EM\_FORMATRANGE 消息

2，实现的代码如下：

//---------------------------------------------------------------------------

\#include <vcl.h>  
\#pragma hdrstop

\#include "Unit1.h"  
//---------------------------------------------------------------------------  
\#pragma package(smart\_init)  
\#pragma resource "\*.dfm"  
TForm1 \*Form1;  
//---------------------------------------------------------------------------  
\_\_fastcall TForm1::TForm1(TComponent\* Owner)  
: TForm(Owner)  
\{  
\}  
//---------------------------------------------------------------------------

void \_\_fastcall TForm1::Button1Click(TObject \*Sender)  
\{  
RichEdit1->Text = RichEdit1->Text.TrimRight();  
int LogX,LogY;  
HDC richdc = GetDC(RichEdit1->Handle);  
LogX = GetDeviceCaps(richdc, LOGPIXELSX);  
LogY = GetDeviceCaps(richdc, LOGPIXELSY);

FORMATRANGE formatrange = \{0\};  
formatrange.hdc = richdc;  
formatrange.hdcTarget = richdc;  
formatrange.rc.left = 0;  
formatrange.rc.top = 0;  
formatrange.rc.right = RichEdit1->ClientWidth \* 1440 / LogX;  
formatrange.rc.bottom= Screen->Height\* 1440 / LogY;  
formatrange.rcPage = formatrange.rc;  
formatrange.chrg.cpMin = 0;  
formatrange.chrg.cpMax = -1;  
RichEdit1->Perform(EM\_FORMATRANGE,0,(long)&formatrange);  
int totalHeight = formatrange.rc.bottom \* LogY / 1440;  
ShowMessage("文本总高度"+IntToStr(formatrange.rc.bottom \* LogY / 1440));  
RichEdit1->Perform(EM\_FORMATRANGE,0,NULL);//free the cache

if (totalHeight > (RichEdit1->ClientHeight+3))  
\{  
ShowMessage("文字超出范围！");  
\}

ReleaseDC(RichEdit1->Handle,richdc);  
\}  
//---------------------------------------------------------------------------  
void \_\_fastcall TForm1::Button2Click(TObject \*Sender)  
\{  
RichEdit1->Font->Size++;  
\}  
//---------------------------------------------------------------------------  
void \_\_fastcall TForm1::Button3Click(TObject \*Sender)  
\{  
RichEdit1->Font->Size--;  
\}  
//---------------------------------------------------------------------------

[BCB _Richedit]: https://www.cnblogs.com/songr/p/5485187.html