Mapserver：尝试使用注释/标签制作地图

I'm trying to make an image with MapServer which only displays one layer with a label. I have written the following mapfile:

MAP
    NAME "TextLayer"
    IMAGETYPE PNG
    EXTENT -180 -90 180 90
    IMAGECOLOR 0 0 255
    PROJECTION
        "init=epsg:4269"
    END
    WEB
        METADATA
            "ows_title" "WMS service"
            "ows_onlineresource"    "XXX.XXX.XXX.XXX"
            "ows_enable_request"    "*"
            "ows_crs" "EPSG:4269"
        END
    END
    LAYER
        NAME "labellayer"
        STATUS ON
        TYPE POINT
        FEATURE
            POINTS 100 100 END
            TEXT "The text on the image"
        END
        CLASS
            LABEL
                SIZE 8
                ANTIALIAS true
                COLOR 255 0 0
                POSITION cc
            END
        END
    END
END

I am generating the image with PHP with ms_newMapObjFromString(). However, all I get is a transparent image without any text. What am I missing?

EDIT: PHP Code:

public function PrintImage($request, $mapFileString)
{
    $mapServer_MapObject = ms_newMapObjFromString($mapFileString);

    ms_ioinstallstdouttobuffer();

    $mapServer_MapObject->owsdispatch($request);

    $contenttype = ms_iostripstdoutbuffercontenttype();

    ms_iostripStdoutBufferContentType();

    //If content type is 'image/png' the image is succesfully requested -> show the image
    if($contenttype == "image/png")
    {
        header('Content-type: image/png');

        echo ms_iogetstdoutbufferbytes();
    }
    //Else an error occured -> show the error
    else
    {
        header('Content-type: xml');

        echo ms_iogetstdoutbufferstring();
    }
}

$MapFileString is the string posted above.

Your map extent does not match the projection you are using. You probably mean the projection EPSG:4326, because -180 -90 180 90 is the maximal extension of this projection.

Another problem is that your point (POINTS 100 100) is outside the bounding box you request (EXTENT -180 -90 180 90) Try putting the point on the center of the image with

POINTS 0 0

PS: if it does not work, post your php code as well

One way of doing this (there may be others) is in your LAYER config you need to add a LABELITEM to identify the attribute in your data to take the label text.

So for example in the below example, the Crude Oil label is the data in the Gen_Type attribute of the input data, and the class for the "Crude Oil" value includes LABEL instructions.

So in the map file we have:

LAYER
    CLASSITEM "Gen_Type"
    DATA "geom FROM public.energy_gen2016"
    EXTENT 29.62017 -1.31861 34.88271 3.69740
    GROUP "ENERGY-GEN"
    INCLUDE "generic-layer-config.map"
    LABELITEM "Gen_Type"
    METADATA
        "GML_FEATUREID" "fid"
        "OWS_ABSTRACT" "Energy generation sites (2016) classified by energy type. The data was downloaded from Data.Ug, and is acquired from the Ministry of Mining and Mineral Development."
        "OWS_DATAURL_HREF" "http://catalog.data.ug/dataset/generation-sites"
        "OWS_EXTENT" "29.62017 -1.31861 34.88271 3.69740"
        "OWS_KEYWORDLIST" "continent@Africa,subcontinent@Eastern Africa,geographicarea@Uganda,serviceprovider@British Geological Survey,DS_TOPIC@utilitiesCommunications,thematic@Energy,DS_DATE@2016"
        "OWS_TITLE" "Energy generation type (2016)"
        INCLUDE "commonLayerMD.map"
    END
    NAME "ENERGY_TYPE_2016"
    TEMPLATE "tmpl/UPP_energy_tpl.html"
    TYPE POINT
    INCLUDE "style/entype.map"
END

and in the 'style' file we have:

    CLASS
        NAME "Crude Oil"
        EXPRESSION {Crude Oil}
        STYLE
            SYMBOL "circlef"
            COLOR "#000000"
            OUTLINECOLOR "#232323"
            SIZE 6
        END
        LABEL
            FONT scb
            TYPE TRUETYPE
            SIZE 8
            COLOR 0 0 0
            ALIGN CENTER
            PRIORITY 10
            BUFFER 1
            PARTIALS TRUE
            POSITION lc
        END
    END