[CorePlot]图标标题

    
    // Graph title
    graph.title = @"This is the Graph Title";
    CPMutableTextStyle *textStyle = [CPMutableTextStyle textStyle];
    textStyle.color = [CPColor grayColor];
    textStyle.fontName = @"Helvetica-Bold";
    textStyle.fontSize = 18.0;
    graph.titleTextStyle = textStyle;
    graph.titleDisplacement = CGPointMake(0.0, 20.0);
    graph.titlePlotAreaFrameAnchor = CPRectAnchorTop;