MeasureCharacterRanges不適合角色？

我嘗試測量該區域在此代碼的字符串包圍每一個字符：MeasureCharacterRanges不適合角色？

void Draw(HDC dc) 
{ 
    using namespace Gdiplus; 
    Graphics graphics(dc); 
    wstring chars; 
    for(int i=32; i<127; ++i) 
    { 
     chars += i; 
     chars += 32; 
    } 

    Font font(L"Times New Roman", 30, FontStyleRegular, UnitPoint); 
    TextRenderingHint hint = TextRenderingHintAntiAlias ; 
    const StringFormat* pStringFormat = StringFormat::GenericTypographic(); 
    StringFormat MeasureFormat(pStringFormat); 
    const float Offset = 60.f; 
    RectF layout(Offset, Offset, m_ScreenWidth - Offset*2, m_ScreenHeight - Offset*2); 
    std::vector<RectF> charSize; 
    for(size_t i=0; i<chars.size(); ++i) 
    { 
     if(i%2 == 0) 
     { 
      CharacterRange range(i, 1); 
      MeasureFormat.SetMeasurableCharacterRanges(1, &range); 
      Region region; 

      graphics.MeasureCharacterRanges(chars.c_str(), -1, &font, layout, &MeasureFormat, 1, &region); 
      RectF rec; 
      region.GetBounds(&rec, &graphics); 
      charSize.push_back(rec); 
     } 
    } 

    graphics.SetTextRenderingHint(hint); 

    for(size_t i=0 ; i<charSize.size(); ++i) 
    { 
     graphics.FillRectangle(&SolidBrush(0xaa998844), charSize[i]); 
    } 

    graphics.DrawString(chars.c_str(), -1, &font, layout, pStringFormat, &SolidBrush(0xff0000ff)); 
}

，這是結果：

screen shot