只是想编译之后立刻运行，像sublime那样从文件读入后输出到下面控制台。
写了个tasks.json

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "0.1.0",
    "tasks": [
        {
            "taskName": "build",
            "command": "g++",
            "isShellCommand": true,
            "args": [
                "-o",
                "${workspaceRoot}/main",
                "${workspaceRoot}/main.cpp"
            ],
            "showOutput": "always"
        },
        {
            "taskName": "run",
            "command": "${workspaceRoot}/main",
            "isShellCommand": true,
            "showOutput": "always"
        }
    ]
}

为啥，第二个任务不会运行。。