'' 完毕：
Imports System.IO
Imports System.Drawing
Imports System.Text
Imports GrapeCity.Documents.Pdf
Imports GrapeCity.Documents.Text
Imports GrapeCity.Documents.Drawing
'' 此示例演示了不同样式的编号列表如何
'' 可以在 GcDocs.Pdf 中呈现。
'' 另请参阅NumberedList。
Public Class NumberedList2
'' 封装示例中使用的页面布局常量：
Private Structure Layout
'' 四周页边距：
Public Shared Margin As Single = 72.0F
'' 相对于项目编号的列表偏移量：
Public Shared ListOffset As Single = 24.0F
'' 列表级缩进：
Public Shared ListIndent As Single = 30.0F
End Structure
'' 定义简单树类型：
Private Class Node
Public Sub New(ByVal txt As String)
Text = txt
End Sub
Public Property Text As String
Public Property Children As List(Of Node) = New List(Of Node)()
End Class
'' 将节点列表呈现为编号列表。
Private Function RenderNodes(ByRef page As Page, ByVal pt As PointF, ByVal nodes As List(Of Node), ByVal level As Integer) As PointF
Dim tlBullet = page.Graphics.CreateTextLayout()
tlBullet.DefaultFormat.Font = StandardFonts.Times
tlBullet.MarginLeft = Layout.ListIndent * level
Dim tlText = New TextLayout(72)
tlText.DefaultFormat.Font = StandardFonts.Times
tlText.MarginLeft = Layout.ListOffset + Layout.ListIndent * level
For i = 0 To nodes.Count - 1
Dim g = page.Graphics
'' 准备项目文本：
tlText.Clear()
tlText.Append(nodes(i).Text)
tlText.PerformLayout(True)
If pt.Y + tlText.ContentHeight > page.Size.Height - Layout.Margin Then
page = page.Doc.NewPage()
g = page.Graphics
pt.Y = Layout.Margin
End If
'' 准备品编号：
tlBullet.Clear()
tlBullet.Append(ItemIdxToString(i, level, tlBullet))
tlBullet.PerformLayout(True)
'' 渲染项目：
g.DrawTextLayout(tlBullet, pt)
g.DrawTextLayout(tlText, pt)
'' 提前插入点：
pt.Y += tlText.ContentHeight
'' 渲染子项：
If nodes(i).Children.Count > 0 Then
pt = RenderNodes(page, pt, nodes(i).Children, level + 1)
End If
Next
Return pt
End Function
'' 将项目索引转换为项目编号表示形式
'' 阿拉伯语 -> 拉丁字母 -> 罗马数字循环。
'' 罗马数字右对齐，其他数字左对齐。
Private Function ItemIdxToString(ByVal itemIdx As Integer, ByVal level As Integer, ByVal tl As TextLayout) As String
Select Case (level Mod 3)
Case 0
tl.MarginLeft = Layout.ListIndent * level
tl.MaxWidth = Nothing
tl.TextAlignment = TextAlignment.Leading
Return $"{itemIdx + 1}."
Case 1
tl.MarginLeft = Layout.ListIndent * level
tl.MaxWidth = Nothing
tl.TextAlignment = TextAlignment.Leading
Return $"{ChrW(AscW("a") + itemIdx)}."
Case 2
tl.MarginLeft = 0
Dim font = tl.DefaultFormat.Font
tl.MaxWidth = Layout.ListIndent * level + tl.DefaultFormat.FontSize
tl.TextAlignment = TextAlignment.Trailing
Return $"{IntToRoman(itemIdx + 1)}."
Case Else
Throw New Exception("Unexpected.")
End Select
End Function
'' 来自http://dotnet-snippets.com/snippet/roman-numerals/667
Private Function IntToRoman(ByVal number As Integer) As String
Dim result = New StringBuilder()
Dim digitsValues = {1, 4, 5, 9, 10, 40, 50, 90, 100, 400, 500, 900, 1000}
Dim romanDigits = {"I", "IV", "V", "IX", "X", "XL", "L", "XC", "C", "CD", "D", "CM", "M"}
While number > 0
For i = digitsValues.Count() - 1 To 0 Step -1
If (number / digitsValues(i) >= 1) Then
number -= digitsValues(i)
result.Append(romanDigits(i).ToLower())
Exit For
End If
Next
End While
Return result.ToString()
End Function
'' 主要入口点：
Function CreatePDF(ByVal stream As Stream) As Integer
Dim doc = New GcPdfDocument()
Dim page = doc.NewPage()
RenderNodes(page, New PointF(Layout.Margin, Layout.Margin), _arthrapods.Children, 0)
''
'' 完毕：
doc.Save(stream)
Return doc.Pages.Count
End Function
'' 示例树数据：
Private _arthrapods As New Node("Animalia Arthrapoda") With
{
.Children = New List(Of Node) From
{
New Node("Insecta") With
{
.Children = New List(Of Node) From
{
New Node("Archaeognatha") With
{
.Children = New List(Of Node) From
{
New Node("Protozoa")
}
},
New Node("Thysanura") With
{
.Children = New List(Of Node) From
{
New Node("Silverfish")
}
},
New Node("Ephemeoptera") With
{
.Children = New List(Of Node) From
{
New Node("Mafly")
}
},
New Node("Odonata") With
{
.Children = New List(Of Node) From
{
New Node("Dragonfly"),
New Node("Azure Damzelfly"),
New Node("Emerald Damzelfly")
}
},
New Node("Orthoptera") With
{
.Children = New List(Of Node) From
{
New Node("Grasshopper"),
New Node("Cricket"),
New Node("Cave Cricket")
}
},
New Node("Phasmatodea") With
{
.Children = New List(Of Node) From
{
New Node("Walking Stick"),
New Node("Leaf Bug")
}
},
New Node("Mantodea") With
{
.Children = New List(Of Node) From
{
New Node("Praying Mantis")
}
},
New Node("Blattoeda") With
{
.Children = New List(Of Node) From
{
New Node("Cockroach")
}
},
New Node("Isoptera") With
{
.Children = New List(Of Node) From
{
New Node("Termite")
}
},
New Node("Phithiraptera") With
{
.Children = New List(Of Node) From
{
New Node("Bird Lice"),
New Node("Human Lice"),
New Node("Pubic Lice")
}
},
New Node("Hemiptera") With
{
.Children = New List(Of Node) From
{
New Node("Cicada"),
New Node("Pond Skater"),
New Node("Tree Hopper"),
New Node("Stink Bug"),
New Node("Thrip"),
New Node("Alderfly")
}
},
New Node("Siphonatera") With
{
.Children = New List(Of Node) From
{
New Node("Flea")
}
}
}
},
New Node("Myriapoda") With
{
.Children = New List(Of Node) From
{
New Node("Chilopoda") With
{
.Children = New List(Of Node) From
{
New Node("Centipede")
}
},
New Node("Diplopoda") With
{
.Children = New List(Of Node) From
{
New Node("Millipede"),
New Node("Pitbug")
}
}
}
},
New Node("Crustacea") With
{
.Children = New List(Of Node) From
{
New Node("Branchiopod") With
{
.Children = New List(Of Node) From
{
New Node("Brine Shrimp"),
New Node("Water Flea")
}
},
New Node("Maxillopod") With
{
.Children = New List(Of Node) From
{
New Node("Cyclopoid"),
New Node("Calgid"),
New Node("Barnacles")
}
},
New Node("Malacostracan") With
{
.Children = New List(Of Node) From
{
New Node("Krill"),
New Node("Prawn"),
New Node("Shrimp"),
New Node("Cancrid Crab"),
New Node("Fidder Crab"),
New Node("Spider Crab"),
New Node("Lobster"),
New Node("Hermit Crab"),
New Node("Cray Fish")
}
}
}
},
New Node("Pycnogonida") With
{
.Children = New List(Of Node) From
{
New Node("Pycnogonida") With
{
.Children = New List(Of Node) From
{
New Node("Sea Spider")
}
}
}
},
New Node("Merostomata") With
{
.Children = New List(Of Node) From
{
New Node("Merostomata") With
{
.Children = New List(Of Node) From
{
New Node("Horseshoe Spider")
}
}
}
},
New Node("Arachnida") With
{
.Children = New List(Of Node) From
{
New Node("Scorpiones") With
{
.Children = New List(Of Node) From
{
New Node("Buthid"),
New Node("Imperial Scorpion")
}
},
New Node("Pseudoscorpions") With
{
.Children = New List(Of Node) From
{
New Node("Neobisiid"),
New Node("Cheliferid")
}
},
New Node("Solfigugae") With
{
.Children = New List(Of Node) From
{
New Node("Wind Scorpion")
}
},
New Node("Acari") With
{
.Children = New List(Of Node) From
{
New Node("Tick"),
New Node("Mite")
}
},
New Node("Araneae") With
{
.Children = New List(Of Node) From
{
New Node("Crib Weaver"),
New Node("Funnel-web Spider"),
New Node("Funnel Weaver"),
New Node("Water Spider"),
New Node("Jumping Spider"),
New Node("Wolf Spider"),
New Node("Nursery-web Spider"),
New Node("Crab Spider"),
New Node("Black Widow"),
New Node("Tiger Oriental Tarantula"),
New Node("Mexican Red-legged Tarantula")
}
}
}
}
}
}
End Class