开始学习awt,swing，请问两个初级问题。

Question

画线平滑：      g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
      g.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL,RenderingHints.VALUE_STROKE_DEFAULT);
画线恢复到默认状况：      g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_OFF);
      g.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL,RenderingHints.VALUE_STROKE_PURE);

Answer 1

1.
Font font=new Font("宋体",Font.PLAIN,25);
g.setFont(font);
FontMetrics fm=this.getFontMetrics(font);
String s="字符串长度";
int width=fm.stringWidth(s);//长度
int height=fm.getHeight();//高度
2.
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);

Answer 2

提交为FAQ后发现落了一点东西，补充一下Graphics2D g2d = (Graphics2D)g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);