I know how to do it with single file

**keybindings.json**
 [
    {
      "key": "ctrl+j+a",
      "command": "workbench.action.tasks.runTask",
      "args": "csc"    //just for example
    }
]

**tasks.json**
{
    "version": "1.0.0",
    "tasks": [
        {       
            "label": "csc",
            "type": "shell",
            "command": "/test/scripts/csc",
            "args": ["${fileDirname}", "${fileBasename}"]   
        }
    ]
}

Is it possible to do the same thing with multiple files opened in editor ? Sorry if i did something wrong i'm new at scripting.