我搜索了很多,尝试了很多,但我找不到正确的解决方案.
我想知道有什么方法可以确定指定字体中的精确字形高度？
我的意思是这里,当我想确定DOT字形的高度,我应该收到小高度,但不是高度与paddings或字体大小.
我找到了确定精确字形宽度here(我已经使用第二种方法)的解决方案,但它不适用于高度.
更新：我需要.NET 1.1的解决方案
解决方法
获取角色指标并不难. GDI包含一个函数
GetGlyphOutline,您可以使用GGO_METRICS常量调用该函数,以获取在呈现时包含字形所需的最小包围矩形的高度和宽度.即,字体Arial中的点的10点字形将给出一个1×1像素的矩形,对于字母I 95x.14,如果字体的大小为100点.
这些是P / Invoke电话的声明：
// the declarations
public struct FIXED
{
public short fract;
public short value;
}
public struct MAT2
{
[MarshalAs(UnmanagedType.Struct)] public FIXED eM11;
[MarshalAs(UnmanagedType.Struct)] public FIXED eM12;
[MarshalAs(UnmanagedType.Struct)] public FIXED eM21;
[MarshalAs(UnmanagedType.Struct)] public FIXED eM22;
}
[StructLayout(LayoutKind.Sequential)]
public struct POINT
{
public int x;
public int y;
}
[StructLayout(LayoutKind.Sequential)]
public struct POINTFX
{
[MarshalAs(UnmanagedType.Struct)] public FIXED x;
[MarshalAs(UnmanagedType.Struct)] public FIXED y;
}
[StructLayout(LayoutKind.Sequential)]
public struct GLYPHMETRICS
{
public int gmBlackBoxX;
public int gmBlackBoxY;
[MarshalAs(UnmanagedType.Struct)] public POINT gmptGlyphOrigin;
[MarshalAs(UnmanagedType.Struct)] public POINTFX gmptfxGlyphOrigin;
public short gmCellIncX;
public short gmCellIncY;
}
private const int GGO_METRICS = 0;
private const uint GDI_ERROR = 0xFFFFFFFF;
[DllImport("gdi32.dll")]
static extern uint GetGlyphOutline(IntPtr hdc,uint uChar,uint uFormat,out GLYPHMETRICS lpgm,uint cbBuffer,IntPtr lpvBuffer,ref MAT2 lpmat2);
[DllImport("gdi32.dll",ExactSpelling = true,PreserveSig = true,SetLastError = true)]
static extern IntPtr SelectObject(IntPtr hdc,IntPtr hgdiobj);
实际的代码,相当琐碎,如果你不考虑P / Invoke的冗余.我测试了代码,它工作(您可以调整以获得宽度从GLYPHMETRICS).
注意：这是特设代码,在现实世界中,您应该使用ReleaseHandle和DeleteObject清理HDC和对象.感谢user2173353的评论指出了这一点.
// if you want exact metrics,use a high font size and divide the result
// otherwise,the resulting rectangle is rounded to nearest int
private int GetGlyphHeight(char letter,string fontName,float fontPointSize)
{
// init the font. Probably better to do this outside this function for performance
Font font = new Font(new FontFamily(fontName),fontPointSize);
GLYPHMETRICS metrics;
// identity matrix,required
MAT2 matrix = new MAT2
{
eM11 = {value = 1},eM12 = {value = 0},eM21 = {value = 0},eM22 = {value = 1}
};
// HDC needed,we use a bitmap
using(Bitmap b = new Bitmap(1,1))
using (Graphics g = Graphics.FromImage(b))
{
IntPtr hdc = g.GetHdc();
IntPtr prev = SelectObject(hdc,font.ToHfont());
uint retVal = GetGlyphOutline(
/* handle to DC */ hdc,/* the char/glyph */ letter,/* format param */ GGO_METRICS,/* glyph-metrics */ out metrics,/* buffer,ignore */ 0,ignore */ IntPtr.Zero,/* trans-matrix */ ref matrix);
if(retVal == GDI_ERROR)
{
// something went wrong. Raise your own error here,// or just silently ignore
return 0;
}
// return the height of the smallest rectangle containing the glyph
return metrics.gmBlackBoxY;
}
}
