Gets or sets the total sum of all of the advance values that correspond to character data within this element, including the advance value on the glyph (horizontal or vertical), the effect of properties 'letter-spacing' and 'word-spacing' and adjustments due to attributes 'dx' and 'dy' on this 'text' or 'tspan' element or any descendants.

'宣言
 
Public Property TextLength As System.Nullable(Of SvgLength)

public System.Nullable<SvgLength> TextLength {get; set;}