可以嵌入在markdown代码中的mermaid

mermaid的好处是可以在写markdown文档的同时，就直接可以画图了。

独立使用mermaid

可以通过npm安装mermad：

npm install -g mermaidnpm install -g phantomjs

mermaid依赖于phantomjs

下面是mermaid的帮助信息：

Usage: mermaid [options] 
    
     ...file    The mermaid description file to be renderedOptions:  -s --svg             Output SVG instead of PNG (experimental)  -p --png             If SVG was selected, and you also want PNG, set this flag  -o --outputDir       Directory to save files, will be created automatically, defaults to `cwd`  -e --phantomPath     Specify the path to the phantomjs executable  -t --css             Specify the path to a CSS file to be included when processing output  -c --sequenceConfig  Specify the path to the file with the configuration to be applied in the sequence diagram  -g --ganttConfig     Specify the path to the file with the configuration to be applied in the gantt diagram  -h --help            Show this message  -v --verbose         Show logging  -w --width           width of the generated png (number)  --version            Print version and quit
    

mermaid数据流图速成

决定图的方向

与graphviz不同，graph语句首先需要设置图的方向

• TD: 默认方向，从上到下
• TB: 从上到下
• BT: 从下到上
• LR: 从左到右
• RL: 从右到左

例：

graph TB;    Context_sendbroadcast --> ContextWrapper_sendBroadcast;    ContextWrapper_sendBroadcast --> ContextImpl_sendBroadcast;    ContextImpl_sendBroadcast --> ActivityManagerService_broadcastIntent;

与graphviz的不同

graphviz的dot图是用“节点1 -> 节点2”的格式，而mermaid是用“节点1 --> 节点2”的方式，中间多了一个"-".

属性定义方面，mermaid可以用[]和()几种方式来决定图形的方式。

graph TD;    Context_sendbroadcast(Context.sendBroadcast Intent);    ContextWrapper_sendBroadcast[ContextWrapper.sendBroadcast Intent];    Context_sendbroadcast --> ContextWrapper_sendBroadcast;

Context_sendbroadcast就是圆脚的矩形，而ContextWrapper_sendBroadcast就是方的。

需要注意的一点，在标签属性定义的时候，不能出现()[]之类引起误会的符号。官方文档说可以用""来引起来，不过在我的版本上有点问题。

下面还是看跟上面一篇中所讲的graphviz完全一样的图的例子：

graph TD    Context_sendbroadcast[Context.sendBroadcast Intent];    Context_sendbroadcast_asUser[Context.sendBroadcastAsUser Intent,UserHandle];    Context_sendOrderedBroadcast[Context.sendOrderedBroadcast Intent,String,BroadcastReceiver,Handler,int,String,Bundle];    Context_sendOrderedBroadcast2[Context.sendOrderedBroadcast Intent,String];    Context_sendStickyBroadcast[Context.sendStickyBroadcast Intent];    Context_sendStickyBroadcast2[Context.sendStickyOrderedBroadcast Intent,BroadcastReceiver,Handler,int,String,Bundle];    ContextWrapper_sendBroadcast[ContextWrapper.sendBroadcast Intent];    ContextWrapper_sendOrderedBroadcast2[ContextWrapper.sendOrderedBroadcast Intent,String];    ContextWrapper_sendOrderedBroadcast[ContextWrapper.sendOrderedBroadcast Intent,String,BroadcastReceiver,Handler,int,String,Bundle];    ContextWrapper_sendStickyBroadcast[ContextWrapper.sendStickyBroadcast Intent];    ContextWrapper_sendStickyBroadcast2[ContextWrapper.sendStickyOrderedBroadcast Intent,BroadcastReceiver,Handler,int,String,Bundle];    ContextWrapper_sendbroadcast_asUser[ContextWrapper.sendBroadcastAsUser Intent,UserHandle];    ContextImpl_sendBroadcast[ContextImpl.sendBroadcast Intent];    ContextImpl_sendOrderedBroadcast2[ContextImpl.sendOrderedBroadcast Intent,String];    ContextImpl_sendOrderedBroadcast[ContextImpl.sendOrderedBroadcast Intent,String,BroadcastReceiver,Handler,int,String,Bundle];    ContextImpl_sendStickyBroadcast[ContextImpl.sendStickyBroadcast Intent];    ContextImpl_sendStickyBroadcast2[ContextImpl.sendStickyOrderedBroadcast Intent,BroadcastReceiver,Handler,int,String,Bundle];    ContextImpl_sendbroadcast_asUser[ContextImpl.sendBroadcastAsUser Intent,UserHandle];    ContextImpl_sendOrderedBroadcast_all(ContextImpl.sendOrderedBroadcast Intent,String,int,BroadcastReceiver,Handler,int,String,Bundle,Bundle);    ActivityManagerService_broadcastIntent(ActivityManagerService.broadcastIntent IApplicationThread,Intent,String,IIntentReceiver,int,String,Bundle,String,int,Bundle,boolean,boolean,int);    Context_sendbroadcast --> ContextWrapper_sendBroadcast;    ContextWrapper_sendBroadcast --> ContextImpl_sendBroadcast;    ContextImpl_sendBroadcast --> ActivityManagerService_broadcastIntent;    Context_sendbroadcast_asUser --> ContextWrapper_sendbroadcast_asUser;    ContextWrapper_sendbroadcast_asUser --> ContextImpl_sendbroadcast_asUser;    ContextImpl_sendbroadcast_asUser --> ActivityManagerService_broadcastIntent;    Context_sendOrderedBroadcast2 --> ContextWrapper_sendOrderedBroadcast2;    ContextWrapper_sendOrderedBroadcast2 --> ContextImpl_sendOrderedBroadcast2;    ContextImpl_sendOrderedBroadcast2 --> ActivityManagerService_broadcastIntent;    Context_sendOrderedBroadcast --> ContextWrapper_sendOrderedBroadcast;    ContextWrapper_sendOrderedBroadcast --> ContextImpl_sendOrderedBroadcast;    ContextImpl_sendOrderedBroadcast --> ContextImpl_sendOrderedBroadcast_all;    ContextImpl_sendOrderedBroadcast_all --> ActivityManagerService_broadcastIntent;    Context_sendStickyBroadcast --> ContextWrapper_sendStickyBroadcast;    ContextWrapper_sendStickyBroadcast --> ContextImpl_sendStickyBroadcast;    ContextImpl_sendStickyBroadcast --> ActivityManagerService_broadcastIntent;    Context_sendStickyBroadcast2 --> ContextWrapper_sendStickyBroadcast2;    ContextWrapper_sendStickyBroadcast2 --> ContextImpl_sendStickyBroadcast2;    ContextImpl_sendStickyBroadcast2 --> ActivityManagerService_broadcastIntent;

下面是生成的图片：