xfce桌面默认不支持触摸板点击，搜索了一大圈，最后找到解决方式，记录一下。

第一步，安装驱动

apt-get install xserver-xorg-input-synaptics

第二步，更改设置，在/usr/share/X11/xorg.conf.d/70-synaptics.conf里相应地方增加如下设置：

        Option "TapButton1" "1"
        Option "TapButton2" "3"
        Option "TapButton3" "2"
        Option "VertEdgeScroll" "on"
        Option "VertTwoFingerScroll" "on"
        Option "HorizEdgeScroll" "on"
        Option "HorizTwoFingerScroll" "on"
        Option "CircularScrolling" "on"
        Option "CircScrollTrigger" "2"
        Option "EmulateTwoFingerMinZ" "40"
        Option "EmulateTwoFingerMinW" "8"
        Option "CoastingSpeed" "0"
        Option "FingerLow" "30"
        Option "FingerHigh" "50"
        Option "MaxTapTime" "125"
        Option "VertScrollDelta" "-111"
        Option "HorizScrollDelta" "-111"