Plot[{x, x^2, x + 2}, {x, -5, 5},
AxesLabel -> {Style["x", 23], Style["y", 22]},
TicksStyle -> Directive[Black, 12], Frame -> True,
ColorFunction -> {Black &}, PlotStyle -> {DotDashed, Dashed, Full},
PlotLegends ->
Placed[LineLegend[{"\!\(\*SubsuperscriptBox[\(\[Pi]\), \(i\), \
\(Y\)]\)", "\!\(\*SubsuperscriptBox[\(\[Pi]\), \(c\), \(Y\)]\)",
"\!\(\*SuperscriptBox[\(SW\), \(Y\)]\)"},
LabelStyle -> Directive[10, Bold, Black]], {0, 0}],
PlotLabel -> Style]
请问各位大佬怎么控制图例的线颜色，我想做全是黑色的图例。另外请问一下，怎么讲图例生成到坐标的左上角啊啊，困扰了很久的问题。谢谢

Plot[{x, x^2, x + 2}, {x, -5, 5},
AxesLabel -> {Style["x", 23], Style["y", 22]},
TicksStyle -> Directive[Black, 12], Frame -> True,
PlotStyle -> {{Black, DotDashed}, {Black, Dashed}, {Black, Full}},
PlotLegends ->
Placed[{"\!\(\*SubsuperscriptBox[\(\[Pi]\), \(i\), \(Y\)]\)",
"\!\(\*SubsuperscriptBox[\(\[Pi]\), \(c\), \(Y\)]\)",
"\!\(\*SuperscriptBox[\(SW\), \(Y\)]\)"}, {Left, Top}],
PlotLabel -> Style]