微信公众平台——接收普通消息

微信公众平台——接收普通消息

开发模式下的接收消息基础接口，可用来接收普通用户发送的文本消息、图片消息、语音消息、视频消息、小视频消息、地理位置消息、链接消息。

type
TMsgType = (event, text, image, voice, video, location, link);

TMessage = Record
ToUserName: String;
FromUserName: String;
CreateTime: Integer;
MsgType: String;
end;

uses System.SysUtils, System.JSON, TypInfo, Xml.XMLIntf, Xml.XMLDoc, ActiveX;

function ReplyText(Msg: TMessage; MsgText: String): RawByteString;
var
X: IXMLDocument;
begin
X := NewXMLDocument;
try
X.Xml.text := TextMsg;
X.Active := true;
with X.DocumentElement.ChildNodes do
begin
Nodes['ToUserName'].NodeValue := Msg.FromUserName;
Nodes['FromUserName'].NodeValue := Msg.ToUserName;
Nodes['CreateTime'].NodeValue := UnixTime(now);
Nodes['MsgType'].NodeValue := 'text';
Nodes['Content'].NodeValue := MsgText;
end;
Result := UTF8Encode(X.Xml.text);
finally
X.Active := False;
X := nil;
end;
end;

function ResponseText(M: TMessage; X: IXMLDocument): RawByteString;
begin
Result := ReplyText(M, '有什么问题留言吧，我们会尽快答复您！');
end;

function ResponseImage(M: TMessage; X: IXMLDocument): RawByteString;
begin
Result := ReplyText(M, '您发的图片很漂亮！');
end;

function ResponseVoice(M: TMessage; X: IXMLDocument): RawByteString;
begin
try
with X.DocumentElement.ChildNodes do
begin
Result := ReplyText(M, Format(VoiceMsg,
[Nodes['Recognition'].NodeValue]));
end;
except
Result := ReplyText(M, '没听清您说什么，不过您的声音很有磁性^_^');
end;
end;

function ResponseVideo(M: TMessage; X: IXMLDocument): RawByteString;
begin
Result := ReplyText(M, '什么视频？不会是A片吧？');
end;

function ResponseLocation(M: TMessage; X: IXMLDocument): RawByteString;
begin
Result := ReplyText(M, '把你的位置发给我了，不怕我跟踪你？哈哈！');
end;

function ResponseLink(M: TMessage; X: IXMLDocument): RawByteString;
begin
Result := ReplyText(M, '什么链接？不会木马吧？');
end;

procedure AddLog(S: String);
begin
Form1.Log.Lines.Add(formatdatetime(TimeFormat, now) + ': ' + S);
end;

function Response(M: TMessage; X: IXMLDocument): RawByteString;
var
MsgType: TMsgType;
begin
MsgType := TMsgType(GetEnumValue(TypeInfo(TMsgType), M.MsgType));
case MsgType of
event:
begin
Result := ResponseEvent(M, X);
end;
text:
begin
Result := ResponseText(M, X);
addlog('收到文本消息...' + M.MsgType + ', ' + M.FromUserName);
end;
image:
begin
Result := ResponseImage(M, X);
addlog('收到图片消息...' + M.MsgType + ', ' + M.FromUserName);
end;
voice:
begin
Result := ResponseVoice(M, X);
addlog('收到语音消息...' + M.MsgType + ', ' + M.FromUserName);
end;
video:
begin
Result := ResponseVideo(M, X);
addlog('收到视频消息...' + M.MsgType + ', ' + M.FromUserName);
end;
location:
begin
Result := ResponseLocation(M, X);
addlog('收到位置消息...' + M.MsgType + ', ' + M.FromUserName);
end;
link:
begin
Result := ResponseLink(M, X);
addlog('收到链接消息...' + M.MsgType + ', ' + M.FromUserName);
end
else
begin
Result := '';
addlog('收到未知消息：' + M.MsgType + ', ' + M.FromUserName);
end;
end;
end;

function Analysis(Stream: TStream): RawByteString;
var
X: IXMLDocument;
M: TMessage;
begin
try
X := NewXMLDocument;
X.Xml.BeginUpdate;
X.Xml.text := StreamToString(Stream);
X.Xml.EndUpdate;
X.Active := true;
with X.DocumentElement.ChildNodes do
begin
M.ToUserName := Nodes['ToUserName'].NodeValue;
M.FromUserName := Nodes['FromUserName'].NodeValue;
M.CreateTime := Nodes['CreateTime'].NodeValue;
M.MsgType := Nodes['MsgType'].NodeValue;
end;
Result := Response(M, X);
finally
X.Active := False;
X := nil;
end;
end;

procedure Form1.IdHTTPServerCommandGet(AContext: TIdContext;
ARequestInfo: TIdHTTPRequestInfo; AResponseInfo: TIdHTTPResponseInfo);
begin
if CheckSignature(ARequestInfo) then
if ARequestInfo.Params.Values['echostr'] <> '' then
begin
AResponseInfo.ContentType := 'text/html; charset=UTF-8';
AResponseInfo.ContentText := ARequestInfo.Params.Values['echostr'];
end
else
begin
if ARequestInfo.PostStream <> nil then
begin
CoInitialize(nil);
try
AResponseInfo.ContentType := 'text/html; charset=UTF-8';
AResponseInfo.ContentText := Analysis(ARequestInfo.PostStream);
finally
CoUninitialize;
end;
end;
end;
end;