Use the HasButtonsCustom property to assign new appearance for +/- buttons, when HasButtons property is exCustom. Use the Images, ReplaceIcon methods to load new icons to the control's icons collection. Use the Expanded property to expand or collapse a node by code. The control fires the Expand event when user expands or collapse a node. Use the ButtonsAlign property to specify the position of +/- buttons inside nodes. Use the Image property to assign an icon to a node. Use the Picture property to load a picture to a node. 

The following VB sample assigns different +/- buttons when expanding or collapsing the parent nodes:

With ChartView1
    .BeginUpdate
    .Images "gBJJgBAICAAGAAEAAQhYAf8Pf4hh0QihCJo2AEZjQAjEZFEaIEaEEaAIAkcbk0olUrlktl0vmExmUzmk1m03nE5nU7nk9n0/oFBoVDolFo1HpFJpVLplNp1PqFRqVTqlVq1XrFZrVbrldr1fsFhsVjslls1ntFptVrtltt1vuFxuVzul1u13vF5vV7vl9v1/wGBwWDwmFw2HxGJxWLxmNx2PyGRyWTymVy2XzGZzWbzmdz2f0Gh0WjwEWH0r08ekEikgAkso184iGkicPjcU2+zjW4jTnZ++jbv4Tvjbu4fF48adAv5fI4XO4ka4fRjO+4G73UZ3na7IAgI="
    .HasButtons = exCustom
    .HasButtonsCustom(False) = 1
    .HasButtonsCustom(True) = 2
    .EndUpdate
End With

The following C++ sample assigns different +/- buttons when expanding or collapsing the parent nodes:

m_chartview.BeginUpdate();
m_chartview.Images(COleVariant("gBJJgBAICAAGAAEAAQhYAf8Pf4hh0QihCJo2AEZjQAjEZFEaIEaEEaAIAkcbk0olUrlktl0vmExmUzmk1m03nE5nU7nk9n0/oFBoVDolFo1HpFJpVLplNp1PqFRqVTqlVq1XrFZrVbrldr1fsFhsVjslls1ntFptVrtltt1vuFxuVzul1u13vF5vV7vl9v1/wGBwWDwmFw2HxGJxWLxmNx2PyGRyWTymVy2XzGZzWbzmdz2f0Gh0WjwEWH0r08ekEikgAkso184iGkicPjcU2+zjW4jTnZ++jbv4Tvjbu4fF48adAv5fI4XO4ka4fRjO+4G73UZ3na7IAgI="));
m_chartview.SetHasButtons( 4 /*exCustom*/ );
m_chartview.SetHasButtonsCustom( FALSE, 1 );
m_chartview.SetHasButtonsCustom( TRUE, 2 );
m_chartview.EndUpdate();

The following VB.NET sample assigns different +/- buttons when expanding or collapsing the parent nodes:

With AxChartView1
    .Images("gBJJgBAICAAGAAEAAQhYAf8Pf4hh0QihCJo2AEZjQAjEZFEaIEaEEaAIAkcbk0olUrlktl0vmExmUzmk1m03nE5nU7nk9n0/oFBoVDolFo1HpFJpVLplNp1PqFRqVTqlVq1XrFZrVbrldr1fsFhsVjslls1ntFptVrtltt1vuFxuVzul1u13vF5vV7vl9v1/wGBwWDwmFw2HxGJxWLxmNx2PyGRyWTymVy2XzGZzWbzmdz2f0Gh0WjwEWH0r08ekEikgAkso184iGkicPjcU2+zjW4jTnZ++jbv4Tvjbu4fF48adAv5fI4XO4ka4fRjO+4G73UZ3na7IAgI=")
    .HasButtons = EXORGCHARTLib.ExpandButtonEnum.exCustom
    .set_HasButtonsCustom(False, 1)
    .set_HasButtonsCustom(True, 2)
End With

The following C# sample assigns different +/- buttons when expanding or collapsing the parent nodes:

axChartView1.BeginUpdate();
axChartView1.Images("gBJJgBAICAAGAAEAAQhYAf8Pf4hh0QihCJo2AEZjQAjEZFEaIEaEEaAIAkcbk0olUrlktl0vmExmUzmk1m03nE5nU7nk9n0/oFBoVDolFo1HpFJpVLplNp1PqFRqVTqlVq1XrFZrVbrldr1fsFhsVjslls1ntFptVrtltt1vuFxuVzul1u13vF5vV7vl9v1/wGBwWDwmFw2HxGJxWLxmNx2PyGRyWTymVy2XzGZzWbzmdz2f0Gh0WjwEWH0r08ekEikgAkso184iGkicPjcU2+zjW4jTnZ++jbv4Tvjbu4fF48adAv5fI4XO4ka4fRjO+4G73UZ3na7IAgI=");
axChartView1.HasButtons = EXORGCHARTLib.ExpandButtonEnum.exCustom;
axChartView1.set_HasButtonsCustom(false, 1);
axChartView1.set_HasButtonsCustom(true, 2);
axChartView1.EndUpdate();

The following VFP sample assigns different +/- buttons when expanding or collapsing the parent nodes:

local s
s = "gBJJgBAICAAEg4ACEKAD/hz/EMNh8TIRNGwAjEZAEXjAojJAjMLjABAAgjUYkUnlUrlktl0vmExmUzmk1m03nE5nU7nk9n0/oFBoVDolFo1HpFJpVLplNp1PqFRqVTqlVq1XrFZrVbrldr1fsFhsVjslls1ntFptVrtltt1vuFxuVzul1u13vF5vV7vl9v0/io+leCjs"
s = s + "fkMZkkkjSAncPiUOjUTyOOjOSjLnZ+YjTvzjvjTuzuf0MZdAv0uizmoz0ZzurjGYzWVykYy202YAgIA="

with thisform.ChartView1
    .BeginUpdate()
    .Images(s)
    .HasButtons = 4 && exCustom
    local t
    t = "HasButtonsCustom(false) = 1" + chr(13) + chr(10)
    t = t + "HasButtonsCustom(true) = 2"
    .Template = t
    .EndUpdate
endwith