iOS 环信消息撤回

这两天在做环信的消息回撤，在网上找了许久没有这种案例，之后官方的一些方法，但是自己做，还是需要花点时间去整理，所以我决定等我把这个做好之后，分享给大家，如果做的不好多多指教，谢谢～

首先要实现消息撤回就是两个步骤，一个是发送要回撤的透传消息 。一个是接收透传信息，删除要回撤的消息。

第一步 ： ChatViewController.m 自己定义一个

UIMenuItem *_messageRetracementMenuItem;

第二步

这个方法里面添加一下撤回字段，我把整段都复制过来了，你们对一下

- (void)showMenuViewController:(UIView *)showInView

andIndexPath:(NSIndexPath *)indexPath

messageType:(EMMessageBodyType)messageType

{

if (self.menuController == nil) {

self.menuController = [UIMenuController sharedMenuController];

}

if (_deleteMenuItem == nil) {

_deleteMenuItem = [[UIMenuItem alloc] initWithTitle:@"删除" action:@selector(deleteMenuAction:)];

}

if (_copyMenuItem == nil) {

_copyMenuItem = [[UIMenuItem alloc] initWithTitle:@"复制" action:@selector(copyMenuAction:)];

}

if (_transpondMenuItem == nil) {

_transpondMenuItem = [[UIMenuItem alloc] initWithTitle:@"转发" action:@selector(transpondMenuAction:)];

}

if (_messageRetracementMenuItem == nil) {

_messageRetracementMenuItem = [[UIMenuItem alloc] initWithTitle:@"撤回" action:@selector(messageRetracementMenuAction:)];

}

NSString *loginUsername =  [[EMClient sharedClient] currentUsername];

id<IMessageModel> model = [self.dataArray objectAtIndex:self.menuIndexPath.row];

if (messageType == EMMessageBodyTypeText) {

if ([loginUsername isEqualToString:model.message.from]) {

[self.menuController setMenuItems:@[_copyMenuItem, _deleteMenuItem,_transpondMenuItem,_messageRetracementMenuItem]];

} else {

[self.menuController setMenuItems:@[_copyMenuItem, _deleteMenuItem,_transpondMenuItem]];

}

} else if (messageType == EMMessageBodyTypeImage){

if ([loginUsername isEqualToString:model.message.from]) {

[self.menuController setMenuItems:@[_deleteMenuItem,_transpondMenuItem,_messageRetracementMenuItem]];

} else {

[self.menuController setMenuItems:@[_deleteMenuItem,_transpondMenuItem]];

}

} else {

if ([loginUsername isEqualToString:model.message.from]) {

[self.menuController setMenuItems:@[_deleteMenuItem,_messageRetracementMenuItem]];

} else {

[self.menuController setMenuItems:@[_deleteMenuItem]];

}

}

[self.menuController setTargetRect:showInView.frame inView:showInView.superview];

[self.menuController setMenuVisible:YES animated:YES];

}

第三步：实现这个回撤的方法 ，我这边做的是在两分钟内撤回，超过两分钟提示

- (void)messageRetracementMenuAction:(id)sender {

if (self.menuIndexPath && self.menuIndexPath.row > 0) {

id<IMessageModel> model = [self.dataArray objectAtIndex:self.menuIndexPath.row];

NSString *messageId  = model.message.messageId;

// 发送这条消息在服务器的时间戳

NSTimeInterval time1 = (model.message.serverTime) / 1000.0;

// 当前的时间戳

NSTimeInterval nowTime = [[NSDate date] timeIntervalSince1970];

NSTimeInterval cha = nowTime - time1;

NSInteger timecha = cha;

if (timecha <= 120) {

[self revokeMessageWithMessageId:messageId conversationId:self.conversation.conversationId];

} else {

[self showHint:@"消息已经超过两分钟 无法撤回"];

}

}

}

//  你撤回之后会发现你消息撤回了，但是还在，但是你要重新运行一下撤回的消息就会没有，所以就是有一步当你撤回的时候，还要手动删除一下。

主要删除 self.conversation，self.dataArray，self.messsagesSource，这三个，然后刷新一下。

其中  REVOKE_FLAG 和 msgId 一定要和安卓对应，两边要写一样的，要不然另一方撤回这边是接收不到的或者你这边撤回另一方收不到。

还有 message.chatType 也要注意，如果你做的不只单聊，那就要判断一下，我上面代码有些，一个群聊，一个单聊。

／／ 发送回撤的透传消息

- (void)revokeMessageWithMessageId:(NSString *)aMessageId

conversationId:(NSString *)conversationId {

EMCmdMessageBody *body = [[EMCmdMessageBody alloc] initWithAction:@"REVOKE_FLAG"];

NSDictionary *ext = @{@"msgId":aMessageId};

NSString *currentUsername = [EMClient sharedClient].currentUsername;

EMMessage *message = [[EMMessage alloc] initWithConversationID:conversationId from:currentUsername  to:conversationId body:body ext:ext];

if (self.conversation.type == EMConversationTypeGroupChat){

message.chatType = EMChatTypeGroupChat;

} else {

message.chatType = EMChatTypeChat;

}

//发送cmd消息

[[EMClient sharedClient].chatManager asyncSendMessage:message progress:nil completion:^(EMMessage *message, EMError *error) {

if (!error) {

NSLog(@"发送成功");

// 需要自己从dataArray里将聊天消息删掉， 还有self.conversation里，最后刷新

NSMutableIndexSet *indexs = [NSMutableIndexSet indexSetWithIndex:self.menuIndexPath.row];

NSMutableArray *indexPaths = [NSMutableArray arrayWithObjects:self.menuIndexPath, nil];

[self.conversation deleteMessageWithId:aMessageId];

[self.messsagesSource removeObject:message];

if (self.menuIndexPath.row - 1 >= 0) {

id nextMessage = nil;

id prevMessage = [self.dataArray objectAtIndex:(self.menuIndexPath.row - 1)];

if (self.menuIndexPath.row + 1 < [self.dataArray count]) {

nextMessage = [self.dataArray objectAtIndex:(self.menuIndexPath.row + 1)];

}

if ((!nextMessage || [nextMessage isKindOfClass:[NSString class]]) && [prevMessage isKindOfClass:[NSString class]]) {

[indexs addIndex:self.menuIndexPath.row - 1];

[indexPaths addObject:[NSIndexPath indexPathForRow:(self.menuIndexPath.row - 1) inSection:0]];

}

}

[self.dataArray removeObjectsAtIndexes:indexs];

[self.tableView beginUpdates];

[self.tableView deleteRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationFade];

[self.tableView endUpdates];

if ([self.dataArray count] == 0) {

self.messageTimeIntervalTag = -1;

}

}  else {

NSLog(@"发送失败");

}

}];

}

第四步：在你接收消息  - (void)didReceiveMessages:(NSArray *)aMessages 这个方法的控制器里 ChatDemoHelper.h  添加接收透传消息的方法，

接收透传消息是环信系统自带的方法。我这边还有一个没做好，就是别人撤回后在当前聊天界面的刷新没刷新好，你们自己做一下。

1 // 接收透传消息

2 - (void)didReceiveCmdMessages:(NSArray *)aCmdMessages {

3     BOOL isRefreshCons = YES;

4     for (EMMessage *cmdMessage in aCmdMessages) {

5         EMCmdMessageBody *body = (EMCmdMessageBody *)cmdMessage.body;

6         if ([body.action isEqualToString:@"REVOKE_FLAG"]) {

7             NSString *revokeMessageId = cmdMessage.ext[@"msgId"];

8             BOOL isSuccess = [self removeRevokeMessageWithChatter:cmdMessage.conversationId conversationType:(EMConversationType)cmdMessage.chatType messageId:revokeMessageId];

9             if (isSuccess)  {

10                 if (_chatVC == nil) {

11                     _chatVC = [self _getCurrentChatView];

12               }

13                 BOOL isChatting = NO;

14                 if (_chatVC)  {

15                      isChatting = [cmdMessage.conversationId isEqualToString:_chatVC.conversation.conversationId];

16                 }

17                 if (_chatVC == nil || !isChatting) {

18                     [self _handleReceivedAtMessage:cmdMessage];

19                     if (self.conversationListVC) {

20                         [[NSNotificationCenter defaultCenter] postNotificationName:@"conversationListRefresh" object:nil];

21                     }

22                     if (self.mainVC) {

23                         [[NSNotificationCenter defaultCenter] postNotificationName:@"conversationListRefresh" object:nil];

24                         [self.mainVC setupUnreadMessageCount];

25                     }

26                     return;

27                 }

28                 if (isChatting) {

29                     isRefreshCons = NO;

30               }

31                 if (isRefreshCons) {

32                     if (self.conversationListVC) {

33                         [[NSNotificationCenter defaultCenter] postNotificationName:@"conversationListRefresh" object:nil];

34                     }

35                     if (self.contactViewVC) {

36                         [[NSNotificationCenter defaultCenter] postNotificationName:@"setupUnreadMessageCount" object:nil];

37                     }

38                 }

39             }  else {

40                 NSLog(@"接收失败");

41             }

42         }

43     }

44 }

1 // 删除消息

2 - (BOOL)removeRevokeMessageWithChatter:(NSString *)aChatter

3                       conversationType:(EMConversationType)type

4                              messageId:(NSString *)messageId{

5

6     EMConversation *conversation = [[EMClient sharedClient].chatManager getConversation:aChatter type:type createIfNotExist:YES];

7     [conversation deleteMessageWithId:messageId];

8     return YES;

9 }

这样就好了，希望能帮到你们～