windows – 重定向当前IO设备以进行第三方例行交互

带注释的代码如下.在这个例子中,我选择将IO重定向到％Stream.GlobalBinary – 你可以随意使用它.关键是标签的特定名称 – 您可以使用$io :: call指定不同的例程,并在其他地方指定这些标签.

//The ProcedureBlock = 0 is important
//  it allows for calling of labels within the ClassMethod
ClassMethod testIORedirection() [ ProcedureBlock = 0 ]
{
    //Create a stream that we will redirect to
    set myStream = ##class(%Stream.GlobalBinary).%New()

    //Redirect IO to the current routine - makes use of the labels defined below
    use $io::("^"_$ZNAME)

    //Enable redirection
    do ##class(%Device).ReDirectIO(1)

    //Any write statements here will be redirected to the labels defined below
    write "Here is a string",!,!
    write "Here is something else",!

    //Disable redirection
    do ##class(%Device).ReDirectIO(0)

    //Print out the stream,to prove that it worked
    write "Now printing the string:",!
    write myStream.Read()


    //Labels that allow for IO redirection
    //Read Character - we don't care about reading
rchr(c)      quit
    //Read a string - we don't care about reading
rstr(sz,to)  quit
    //Write a character - call the output label
wchr(s)      do output($char(s))  quit
    //Write a form feed - call the output label
wff()        do output($char(12))  quit
    //Write a newline - call the output label
wnl()        do output($char(13,10))  quit
    //Write a string - call the output label
wstr(s)      do output(s)  quit
    //Write a tab - call the output label
wtab(s)      do output($char(9))  quit
    //Output label - this is where you would handle what you actually want to do.
    //  in our case,we want to write to myStream
output(s)    do myStream.Write(s)  quit
}