box

This property controls the format of the legend box. 

TDGBox* box;

Parameters:

TDGBox 
{
	UIColor* backgroundColor; // Background Color
	TDGLineFormat* border; // Border Line Format
}

Examples:

chart.legend.box.backgroundColor = [UIColor yellowColor];
chart.legend.box.border.color = [UIColor redColor];
chart.legend.box.border.thickness = 4.0;
chart.legend.box.border.dashStyle = shortDot;