How to send image in chat usig xmpp framework

问题

Hi I am making an app based on the chatting I can send chat messages, but if i add image attachment to the chat message, its not working.here is my message code

if (![[messageStr stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] length] && imgURL==nil) {
      return;
}
NSString *MyString;
NSDate *now = [NSDate date];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"HH:mm,yyyy/MM/dd"];
MyString = [dateFormatter stringFromDate:now];
NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];
NSString *myJID=[defaults valueForKey:@"userNameJID"];

    if ([imgURL length]==0) {
       chatMessageToSendAndPutInDB=[messageStr mutableCopy];
       chatMessageToSendAndPutInDB=[[chatMessageToSendAndPutInDB stringByReplacingOccurrencesOfString:@"'" withString:@""] mutableCopy];
    }else
    {

       receivedDataString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
          chatMessageToSendAndPutInDB=[receivedDataString mutableCopy];
        chatMessageToSendAndPutInDB=[[chatMessageToSendAndPutInDB stringByReplacingOccurrencesOfString:@"'" withString:@""] mutableCopy];

    }
    [DBObject open];
[DBObject insertInTable:@"chatTable" withUserId:myJID withFriendID:[[ASNGlobalClass shareManager] chatToUserJID] withMessage:chatMessageToSendAndPutInDB withTimeDate:MyString withLeftOrRight:0];

 NSXMLElement *body = [NSXMLElement elementWithName:@"body"];
[DBObject closeDatabase];
[self fetchDataFromDatabase];
   if([messageStr length] > 0 ) {

  [body setStringValue:messageStr];
   }else if ([imgURL length]>0){
             [body setStringValue:receivedDataString];
   }    NSXMLElement *message = [NSXMLElement elementWithName:@"message"];
[message addAttributeWithName:@"type" stringValue:@"chat"];

[message addAttributeWithName:@"to" stringValue:chatWithUser];
 NSXMLElement *chatStatus=[NSXMLElement elementWithName:@"composing" xmlns:UIApplicationStateActive];
[message addChild:chatStatus];
[message addChild:body];
[[[self appDelegate] xmppStream] sendElement:message];

I am using xmpp framework and openfire server. and i don't know how to send images.please help me and i am using sqlite for storing and fetching Thanks in advance.

回答1:

attachment element is used to send image in XMPP. you can use following function:

-(void)sendMessage:(NSString *)strText img:(UIImage *)SendImage{
NSXMLElement *body = [NSXMLElement elementWithName:@"body"];
[body setStringValue:strText];

NSXMLElement *message = [NSXMLElement elementWithName:@"message"];
[message addAttributeWithName:@"type" stringValue:@"chat"];
[message addAttributeWithName:@"to" stringValue:userId];
[message addChild:body];

if (SendImage) {
    NSData *dataF = UIImagePNGRepresentation(SendImage);
    NSString *imgStr=[dataF base64EncodedStringWithOptions:0];

    NSXMLElement *ImgAttachement = [NSXMLElement elementWithName:@"attachement"];
    [ImgAttachement setStringValue:imgStr];
    [message addChild:ImgAttachement];
}

[self.xmppStream sendElement:message];
[self.view endEditing:YES];}

回答2:

In Swift3.0

    let data = UIImageJPEGRepresentation(image, 0.1)
    let imageStr = data?.base64EncodedString()

    let body = DDXMLElement.element(withName: "body") as! DDXMLElement
    let messageID = XMPPManager.sharedInstance.xmppStream?.generateUUID()
    let imageAttachement = DDXMLElement.element(withName: "attachment", stringValue: imageStr!) as! DDXMLElement

    let message = DDXMLElement.element(withName: "message") as! DDXMLElement
    message.addAttribute(withName: "type", stringValue: "chat")
    message.addAttribute(withName: "id", stringValue: messageID!)
    message.addAttribute(withName: "to", stringValue: buddyJID.full())
    message.addChild(body)
    message.addChild(imageAttachement)

    XMPPManager.sharedInstance.xmppStream?.send(message)

But If xml size is large, server will return size error. So First upload image to file server and then send url by xmpp protocol

回答3:

For sending a small image to friend you can use the below function, but for sending a large image/video/audio file, it is recommended to share large files via streams "out of band" and use XMPP as signaling protocol - you should just send http:// or rtp:// link, and your buddy's client will download it, or start playing audio/video from given stream.

You can use XEP-0066: Out Of Band Data - simple extension, where you just attach URL to standard element.

Sending Image

//Send Image to friend with message.
-(void)sendMessageWithImage:(NSString *)strText img:(UIImage *)SendImage {

    //Message string with image.
    NSString *messageStr = strText;

    NSXMLElement *body = [NSXMLElement elementWithName:@"body"];
    [body setStringValue:messageStr];

    NSXMLElement *message = [NSXMLElement elementWithName:@"message"];
    [message addAttributeWithName:@"type"stringValue:@"chat"];

    //set "to" string value to friend jid
    [message addAttributeWithName:@"to"stringValue:@"rohit@192.168.0.1"];
    [message addChild:body];

    NSData *dataPic =  UIImagePNGRepresentation(SendImage);

    NSXMLElement *photo = [NSXMLElement elementWithName:@"PHOTO"];
    NSXMLElement *binval = [NSXMLElement elementWithName:@"BINVAL"];
    [photo addChild:binval];

    //convert image to base64String
    NSString *base64String = [dataPic base64EncodedStringWithOptions:0];
    [binval setStringValue:base64String];
    [message addChild:photo];

    [[[self appDelegate] xmppStream] sendElement:message];

}

at Receiver end

XMPPStream Delegate Methode.

- (void)xmppStream:(XMPPStream *)sender didReceiveMessage:(XMPPMessage *)message {

    [self MessageReceive:message];

}

#pragma mark - Receive New Message Methode.
-(void)MessageReceive:(XMPPMessage *)message
{
    //Get friend XMPPUserCoreDataStorageObject object
    XMPPUserCoreDataStorageObject *user = [xmppRosterStorage userForJID:[message from]
                                                             xmppStream:xmppStream
                                                   managedObjectContext:[self managedObjectContext_roster]];

    //Get Message if friend send with image.
    NSString *body = [[message elementForName:@"body"] stringValue];

    //Get Display name of friend.
    NSString *displayName = [user jidStr];

    //Check friend send image or only text message
    if ([message elementForName:@"PHOTO"]) {

        //Get Image from base64String
        NSString *photoHash = [[message elementForName:@"PHOTO"] stringValue];
        NSData* data = [photoHash dataUsingEncoding:NSUTF8StringEncoding];
        NSData *nsdataDecoded = [data initWithBase64EncodedData:data options:0];

        //Here you can get image.
        UIImage *image = [UIImage imageWithData:nsdataDecoded];

    } else {

        //Here you can get friend text message
        NSString *message = body;
    }
}

来源：https://stackoverflow.com/questions/32946115/how-to-send-image-in-chat-usig-xmpp-framework