如您所知，许多UI组件和开发工具不支持RTL，我们可以称之为翻转文本，因为结果相同，例如：
LTR
سلام salam متن راهنما word
RTL
word متن راهنما salam سلام
有没有办法将这个LTR转换为RTL，我不知道怎么做，语言没有关系
实际上，我正在寻找一种解决方案，以在RAD Studio Firemonkey应用程序中完成此操作，正如您所知，Firemonkey应用程序不支持rtl，它已经在rad studio的路线图上，但尚未实现
TPdfWrite.AddUnicodeHexTextUniScribe方法。function TPdfWrite.AddUnicodeHexTextUniScribe(PW: PWideChar;
WinAnsiTTF: TPdfFontTrueType; NextLine: boolean; Canvas: TPdfCanvas): boolean;
var L, i,j: integer;
res: HRESULT;
max, count, numSp: integer;
Sp: PScriptPropertiesArray;
W: PWideChar;
items: array of TScriptItem;
level: array of byte;
VisualToLogical: array of integer;
psc: pointer; // opaque Uniscribe font metric cache
complex,R2L: boolean;
complexs: array of byte;
glyphs: array of TScriptVisAttr;
glyphsCount: integer;
OutGlyphs, LogClust: array of word;
procedure Append(i: Integer);
// local procedure used to add glyphs from items[i] to the PDF content stream
var L: integer;
W: PWideChar;
procedure DefaultAppend;
var tmpU: array of WideChar;
begin
SetLength(tmpU,L+1); // we need the text to be ending with #0
move(W^,tmpU[0],L*2);
AddUnicodeHexTextNoUniScribe(pointer(tmpU),WinAnsiTTF,false,Canvas);
end;
begin
L := items[i+1].iCharPos-items[i].iCharPos; // length of this shapeable item
if L=0 then
exit; // nothing to append
W := PW+items[i].iCharPos;
if not GetBit(complexs[0],i) then begin
// not complex items are rendered as fast as possible
DefaultAppend;
exit;
end;
res := ScriptShape(0,psc,W,L,max,@items[i].a,
pointer(OutGlyphs),pointer(LogClust),pointer(glyphs),glyphsCount);
case res of
E_OUTOFMEMORY: begin // max was not big enough (should never happen)
DefaultAppend;
exit;
end;
E_PENDING, USP_E_SCRIPT_NOT_IN_FONT: begin // need HDC and a selected font object
res := ScriptShape(Canvas.FDoc.GetDCWithFont(WinAnsiTTF),
psc,W,L,max,@items[i].a,
pointer(OutGlyphs),pointer(LogClust),pointer(glyphs),glyphsCount);
if res<>0 then begin // we won't change font if necessary, sorry
// we shall implement the complex technic as stated by
// http://msdn.microsoft.com/en-us/library/dd374105(v=VS.85).aspx
DefaultAppend;
exit;
end;
end;
0: ; // success -> will add glyphs just below
else exit;
end;
// add glyphs to the PDF content
// (NextLine has already been handled: not needed here)
AddGlyphs(pointer(OutGlyphs),glyphsCount,Canvas);
end;
begin
result := false; // on UniScribe error, handle as Unicode
// 1. Breaks a Unicode string into individually shapeable items
L := StrLenW(PW)+1; // include last #0
max := L+2; // should be big enough
SetLength(items,max);
count := 0;
if ScriptItemize(PW,L,max,nil,nil,pointer(items),count)<>0 then
exit; // error trying processing Glyph Shaping -> fast return
// 2. guess if requiring glyph shaping or layout
SetLength(complexs,(count shr 3)+1);
ScriptGetProperties(sP,numSp);
complex := false;
R2L := false;
for i := 0 to Count-2 do // don't need Count-1 = Terminator
if fComplex in sP^[items[i].a.eScript and (1 shl 10-1)]^.fFlags then begin
complex := true;
SetBit(complexs[0],i);
end else
if fRTL in items[i].a.fFlags then
R2L := true;
if not complex then begin
// no glyph shaping -> fast append as normal Unicode Text
if R2L then begin
// handle Right To Left but not Complex text
W := pointer(items); // there is enough temp space in items[]
W[L] := #0;
dec(L);
for i := 0 to L do
W[i] := PW[L-i];
AddUnicodeHexTextNoUniScribe(W,WinAnsiTTF,NextLine,Canvas);
result := true; // mark handled here
end;
exit;
end;
// 3. get Visual Order, i.e. how to render the content from left to right
SetLength(level,count);
for i := 0 to Count-1 do
level[i] := items[i].a.s.uBidiLevel;
SetLength(VisualToLogical,count);
if ScriptLayout(Count,pointer(level),pointer(VisualToLogical),nil)<>0 then
exit;
// 4. now we have enough information to start drawing
result := true;
if NextLine then
Canvas.MoveToNextLine; // manual NextLine handling
// 5. add glyphs for all shapeable items
max := (L*3)shr 1+32; // should be big enough - allocate only once
SetLength(glyphs,max);
SetLength(OutGlyphs,max);
SetLength(LogClust,max);
psc := nil; // cached for the same character style used
if Canvas.RightToLeftText then
// append from right to left visual order
for j := Count-2 downto 0 do // Count-2: ignore last ending item
Append(VisualToLogical[j]) else
// append from left to right visual order
for j := 0 to Count-2 do // Count-2: ignore last ending item
Append(VisualToLogical[j]);
end;
这有点复杂。如果你想正确地完成它，你必须使用Bidi Library和International Components for Unicode。
如果你在使用MFC，这里是如何设置文本方向和对齐方式。假设你的CEdit控件名为m_TextEdit：
void MyDialog::SetLangDirection(bool RTL)
{
DWORD w_dwStyle;
w_dwStyle = GetWindowLong(m_TextEdit.GetSafeHwnd(), GWL_EXSTYLE);
if (RTL)
{
w_dwStyle -= WS_EX_LEFT | WS_EX_LTRREADING;
w_dwStyle |= WS_EX_RIGHT | WS_EX_RTLREADING;
}
else
{
w_dwStyle -= WS_EX_RIGHT | WS_EX_RTLREADING;
w_dwStyle |= WS_EX_LEFT | WS_EX_LTRREADING;
}
SetWindowLong(m_TextEdit.GetSafeHwnd(), GWL_EXSTYLE, w_dwStyle);
}
请查看我的技巧。