C#/VB.NET : Howto improve anti-alias quality

Question

问题:
在 Reporting Service 中，我需要一个垂直的、从底部开始、从下到上、水平居中对齐的文本。

唯一的方法是在代码中创建一个图像，并将该图像设置到标题列中。

请看下面的代码。

基本上，它工作正常，只是抗锯齿质量很糟糕。
我可以做些什么来改进它吗？
请看下面的截图:

垂直文本有点苍白，而不是全黑，
并且文本周围也有涂抹，背景颜色。以及它看起来比左边的文本更粗，但两者都有 arial 格式，大小 8，粗体

我已经尝试了
的所有其他值System.Drawing.Text.TextRenderingHint.*, 以及根本没有抗锯齿

但目前的似乎是最不蹩脚的。我也尝试过更改图像格式，但无济于事:

Function LoadImage2(ByVal sImageText As String, ByVal sImageTextMax As String) As System.Drawing.Image
    sImageTextMax = sImageTextMax.PadRight(15)
    Dim iFontSize As Integer = 8 '//Change this as needed
    Dim bmpImage As New System.Drawing.Bitmap(1, 1)
    Dim iWidth As Integer = 0
    Dim iHeight As Integer = 0
    Dim bgColor As System.Drawing.Color = System.Drawing.Color.LemonChiffon ' LightGray
    Dim TextColor As System.Drawing.Color = System.Drawing.Color.Black

    Dim fsFontStyle As System.Drawing.FontStyle = System.Drawing.FontStyle.Bold

    '// Create the Font object for the image text drawing.
    Dim MyFont As New System.Drawing.Font("Arial", iFontSize, fsFontStyle, System.Drawing.GraphicsUnit.Point)
    '// Create a graphics object to measure the text's width and height.
    'Graphics(MyGraphics = Graphics.FromImage(bmpImage))
    Dim MyGraphics As System.Drawing.Graphics = System.Drawing.Graphics.FromImage(bmpImage)
    '// This is where the bitmap size is determined.
    iWidth = MyGraphics.MeasureString(sImageTextMax, MyFont).Width
    iHeight = MyGraphics.MeasureString(sImageTextMax, MyFont).Height
    '// Create the bmpImage again with the correct size for the text and font.
    'bmpImage = New Drawing.Bitmap(bmpImage, New Drawing.Size(iWidth, iHeight))

    'inches = pixels / dpi
    'pixel = inches * dpi
    '1 centimeter = 0.393700787 inch
    'pixel = cm * 0.393700787  * dpi


    ' vice-versa, because 270° turn
    iHeight = 1 * 0.393700787 * bmpImage.HorizontalResolution 'x DPI
    iWidth = 2.25 * 0.393700787 * bmpImage.VerticalResolution 'y DPI


    bmpImage = New System.Drawing.Bitmap(bmpImage, New System.Drawing.Size(iHeight, iWidth))

    '// Add the colors to the new bitmap.
    MyGraphics = System.Drawing.Graphics.FromImage(bmpImage)
    MyGraphics.Clear(bgColor)
    MyGraphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias

    MyGraphics.TranslateTransform(0, iWidth)
    MyGraphics.RotateTransform(270)

    Dim iTextStartX As Single = 2
    Dim iTextStartY As Single = CSng(iHeight) / CSng(2.0) - CSng(iFontSize) / CSng(2.0)
    iTextStartY -= 2

    MyGraphics.DrawString(sImageText, MyFont, New System.Drawing.SolidBrush(TextColor), iTextStartX, iTextStartY)
    MyGraphics.Flush()
    Return bmpImage
End Function


Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Me.PictureBox1.Image = LoadImage2("test", "")
End Sub



' This piece is only needed in reporting service itselfs
Function LoadImage(ByVal strText As String) As Byte()
    Dim ThisImageFormat As System.Drawing.Imaging.ImageFormat = System.Drawing.Imaging.ImageFormat.Jpeg


    Dim stream As System.IO.MemoryStream = New System.IO.MemoryStream
    Dim bitmapBytes As Byte()
    Dim bmpImage As System.Drawing.Image = LoadImage2(strText, "")


    bmpImage.Save(stream, ThisImageFormat)
    bitmapBytes = stream.ToArray
    stream.Close()
    bmpImage.Dispose()
    Return bitmapBytes
End Function

Answer 1

我遇到了这个问题，但仅限于某些浏览器。我认为这是一个浏览器问题(IE)。 Firefox 和 Chrome 似乎没问题。

最后我决定在 html 中手动构建我的报告并使用 HighCharts对于图形。然后我使用 wkHTMLtoPDF 将其全部渲染为 PDF

它结合得很好，抗锯齿问题已经消失。我认为您可能会在 SQL Reporting Services 中遇到这些问题。