DrawText写竖排文字
painter.drawText(10,50,30,150,Qt::AlignTop | Qt::TextSingleLine | Qt::TextWordWrap,"测试文字");
painter.save();//显将画笔属性进行保存
painter.translate(100,100);//将原点移动到要画文字的地方
painter.rotate(90);//将画笔翻转90度
painter.drawText(0,0,"测试文字");//绘制文字内容
painter.restore();//恢复画笔原有属性