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Graphics.EnumerateMetafile Method (Metafile, Point, Graphics.EnumerateMetafileProc)

Sends the records in the specified Metafile, one at a time, to a callback method for display at a specified point.

Namespace:  System.Drawing
Assembly:  System.Drawing (in System.Drawing.dll)

public void EnumerateMetafile(
	Metafile metafile,
	Point destPoint,
	Graphics.EnumerateMetafileProc callback
)

Parameters

metafile
Type: System.Drawing.Imaging.Metafile

Metafile to enumerate.

destPoint
Type: System.Drawing.Point

Point structure that specifies the location of the upper-left corner of the drawn metafile.

callback
Type: System.Drawing.Graphics.EnumerateMetafileProc

Graphics.EnumerateMetafileProc delegate that specifies the method to which the metafile records are sent.

This method enumerates the records contained in the specified metafile. Each record is individually sent to a callback method specified by the callback parameter. Typically, the callback method calls the PlayRecord method to "play back", or draw, the record.

If the callback method calls PlayRecord, it must do so by calling the PlayRecord method of the specific Metafile that is being enumerated.

The following code example creates a form that has a Metafile as one of its private members. The OnPaint method calls EnumerateMetafile, which calls the form's MetafileCallback method for each record in the metafile. The MetafileCallback method calls the PlayRecord method. Notice that the MetafileCallback method receives the record data as an IntPtr, but the PlayRecord method expects the record data to be a byte array. The call to Copy copies the record data to a byte array so that it can be passed to PlayRecord.


using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;

// for Marshal.Copy 
using System.Runtime.InteropServices; 

public class Form1 : Form
{
    private Metafile metafile1;
    private Graphics.EnumerateMetafileProc metafileDelegate;
    private Point destPoint;
    public Form1()
    {
        metafile1 = new Metafile(@"C:\Test.wmf");
        metafileDelegate = new Graphics.EnumerateMetafileProc(MetafileCallback);
        destPoint = new Point(20, 10);
    }
    protected override void OnPaint(PaintEventArgs e)
    {
        e.Graphics.EnumerateMetafile(metafile1, destPoint, metafileDelegate);
    }
    private bool MetafileCallback(
       EmfPlusRecordType recordType,
       int flags,
       int dataSize,
       IntPtr data,
       PlayRecordCallback callbackData)
    {
        byte[] dataArray = null;
        if (data != IntPtr.Zero)
        {
            // Copy the unmanaged record to a managed byte buffer  
            // that can be used by PlayRecord.
            dataArray = new byte[dataSize];
            Marshal.Copy(data, dataArray, 0, dataSize);
        }

        metafile1.PlayRecord(recordType, flags, dataSize, dataArray);

        return true;
    }

    static void Main()
    {
        Application.Run(new Form1());
    }
}

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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