xmpp中发送文件和接收文件的处理有些不太一样，接收文件处理比较简单，发送稍微复杂一些。
首先需要在XMPPFramework.h中添加文件传输类
//文件传输
//接收文件
#import "XMPPIncomingFileTransfer.h"
//发送文件
#import "XMPPOutgoingFileTransfer.h"
1、文件接收
文件的接收是被动的，所以需要在XMPPStream初始化的地方加入文件接收模块：
//5、文件接收
_xmppIncomingFileTransfer = [[XMPPIncomingFileTransfer alloc] initWithDispatchQueue:dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)];
[_xmppIncomingFileTransfer activate:self.xmppStream];
[_xmppIncomingFileTransfer addDelegate:self delegateQueue:dispatch_get_main_queue()];
//设置为自动接收文件，当然也可以在代理方法中弹出一个alertView来让用户选择是否接收
[_xmppIncomingFileTransfer setAutoAcceptFileTransfers:YES];
添加文件接收的代理XMPPIncomingFileTransferDelegate，
因为文件的接收XMPP不会为我们生成相应的消息，因此必须实现文件接收的代理方法：
#pragma mark ===== 文件接收=======
/** 是否同意对方发文件给我 */
- (void)xmppIncomingFileTransfer:(XMPPIncomingFileTransfer *)sender didReceiveSIOffer:(XMPPIQ *)offer
{
NSLog(@"%s",__FUNCTION__);
//弹出一个是否接收的询问框
// [self.xmppIncomingFileTransfer acceptSIOffer:offer];
} - (void)xmppIncomingFileTransfer:(XMPPIncomingFileTransfer *)sender didSucceedWithData:(NSData *)data named:(NSString *)name
{
XMPPJID *jid = [sender.senderJID copy];
NSLog(@"%s",__FUNCTION__);
//在这个方法里面，我们通过带外来传输的文件
//因此我们的消息同步器，不会帮我们自动生成Message,因此我们需要手动存储message
//根据文件后缀名，判断文件我们是否能够处理，如果不能处理则直接显示。
//图片 音频 （.wav,.mp3,.mp4)
NSString *extension = [name pathExtension];
if (![@"wav" isEqualToString:extension]) {
return;
}
//创建一个XMPPMessage对象,message必须要有from
XMPPMessage *message = [XMPPMessage messageWithType:@"chat" to:jid];
//<span class="s1" style="font-family: 'Comic Sans MS';">给</span><span class="s2" style="font-family: 'Comic Sans MS';">Message</span><span class="s1" style="font-family: 'Comic Sans MS';">添加</span><span class="s2" style="font-family: 'Comic Sans MS';">from</span>
[message addAttributeWithName:@"from" stringValue:sender.senderJID.bare];
[message addSubject:@"audio"]; //保存data
NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
path = [path stringByAppendingPathComponent:[XMPPStream generateUUID]];
path = [path stringByAppendingPathExtension:@"wav"];
[data writeToFile:path atomically:YES]; [message addBody:path.lastPathComponent]; [self.xmppMessageArchivingCoreDataStorage archiveMessage:message outgoing:NO xmppStream:self.xmppStream];
}
当[self.xmppMessageArchivingCoreDataStorage archiveMessage:message outgoing:NO xmppStream:self.xmppStream];执行完毕会发送通知，然后更新相应的历史消息。
2、文件发送
XMPP发送文件的功能依赖于对方客户端，在XMPPStream建立连接之后会询问对方客户端的特性，然后根据返回的特性，判断对方是否能够接收某一种类型的文件。
而XMPP支持的特性有：
<query xmlns="http://jabber.org/protocol/disco#info">
* <identity category="client" type="phone"/>
* <feature var="http://jabber.org/protocol/si"/>
* <feature var="http://jabber.org/protocol/si/profile/file-transfer"/>
* <feature var="http://jabber.org/protocol/bytestreams"/>
* <feature var="http://jabber.org/protocol/ibb"/>
* </query>
首先，在聊天控制器中添加一个property，并添加XMPPOutgoingFileTransferDelegate
@property (nonatomic, strong) XMPPOutgoingFileTransfer *xmppOutgoingFileTransfer;
这里录一段音频，然后发送。
添加一个录音按钮，当按钮按下时开始录音startRecord:，按钮抬起时，发送录音sendRecord:，划出按钮区域取消录音cancelRecord:，
- (IBAction)startRecord:(id)sender {
NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
path = [path stringByAppendingPathComponent:[XMPPStream generateUUID]];
path = [path stringByAppendingPathExtension:@"wav"];
NSURL *URL = [NSURL fileURLWithPath:path];
_recorder = [[AVAudioRecorder alloc] initWithURL:URL settings:nil error:nil];
[_recorder prepareToRecord];
[_recorder record];
}
- (IBAction)sendRecord:(id)sender {
[_recorder stop];
NSArray *resources = [[JKXMPPTool sharedInstance].xmppRosterMemoryStorage sortedResources:YES];
for (XMPPResourceMemoryStorageObject *object in resources) {
if ([object.jid.bare isEqualToString:self.chatJID.bare]) {
NSData *data = [[[NSData alloc] initWithContentsOfURL:_recorder.url] copy];
NSError *err;
[self.xmppOutgoingFileTransfer sendData:data named:_recorder.url.lastPathComponent toRecipient:object.jid description:nil error:&err];
if (err) {
NSLog(@"%@",err);
}
break;
}
}
_recorder = nil;
}
- (IBAction)cancelRecord:(id)sender {
[_recorder stop];
[[NSFileManager defaultManager] removeItemAtURL:_recorder.url error:nil];
_recorder = nil;
}
其中发送录音时的，如果发送失败，会在error中返回，失败信息，我这里用Spark做接收客户端，就返回了对方不支持的失败信息。
另外，发送文件也需要自己手动创建并保存一条消息，可以在发送成功的代理方法中创建并保存消息。
- (void)xmppOutgoingFileTransferDidSucceed:(XMPPOutgoingFileTransfer *)sender
{
NSLog(@"xmppOutgoingFileTransferDidSucceed"); XMPPMessage *message = [XMPPMessage messageWithType:@"chat" to:self.chatJID]; //将这个文件的发送者添加到message的from
[message addAttributeWithName:@"from" stringValue:[JKXMPPTool sharedInstance].xmppStream.myJID.bare];
[message addSubject:@"audio"]; NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
path = [path stringByAppendingPathComponent:sender.outgoingFileName]; [message addBody:path.lastPathComponent]; [[JKXMPPTool sharedInstance].xmppMessageArchivingCoreDataStorage archiveMessage:message outgoing:NO xmppStream:[JKXMPPTool sharedInstance].xmppStream];
}