iOS 环信消息撤回

来源：互联网发布：重力永动机知乎编辑：程序博客网时间：2024/04/30 04:01

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

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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

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- (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];
 }
 
  
</imessagemodel>

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

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- (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) {
         // 开始调用发送消息回撤的方法
           [self revokeMessageWithMessageId:messageId conversationId:self.conversation.conversationId];
         } else {
             [self showHint:@"消息已经超过两分钟 无法撤回"];
       }
     }
 }
</imessagemodel>

// 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，我下面代码有些，一个群聊，一个单聊。

／／发送回撤的透传消息

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- (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.m 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。

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1 // 接收透传消息
 
  - (void)didReceiveCmdMessages:(NSArray *)aCmdMessages {
     BOOL isRefreshCons = YES;
      for (EMMessage *cmdMessage in aCmdMessages) {
          EMCmdMessageBody *body = (EMCmdMessageBody *)cmdMessage.body;
          if ([body.action isEqualToString:@"REVOKE_FLAG"]) {
             NSString *revokeMessageId = cmdMessage.ext[@"msgId"];
             BOOL isSuccess = [self removeRevokeMessageWithChatter:cmdMessage.conversationId conversationType:(EMConversationType)cmdMessage.chatType messageId:revokeMessageId];
                if (isSuccess)  {
                 if (_chatVC == nil) {
                      _chatVC = [self _getCurrentChatView];
               }
                   BOOL isChatting = NO;
                 if (_chatVC)  {
                      isChatting = [cmdMessage.conversationId isEqualToString:_chatVC.conversation.conversationId];
                }
                  if (_chatVC == nil || !isChatting) {
                      [self _handleReceivedAtMessage:cmdMessage];
                       if (self.conversationListVC) {
                         [[NSNotificationCenter defaultCenter] postNotificationName:@"conversationListRefresh" object:nil];
                      }
                       if (self.mainVC) {
                           [[NSNotificationCenter defaultCenter] postNotificationName:@"conversationListRefresh" object:nil];
                           [self.mainVC setupUnreadMessageCount];
                       }
                      return;
                   }
                   if (isChatting) {
                       isRefreshCons = NO;
                 }
                  if (isRefreshCons) {
                     if (self.conversationListVC) {
                         [[NSNotificationCenter defaultCenter] postNotificationName:@"conversationListRefresh" object:nil];
                     }
                     if (self.contactViewVC) {
                        [[NSNotificationCenter defaultCenter] postNotificationName:@"setupUnreadMessageCount" object:nil];
                     }
                  }
               }  else {
                NSLog(@"接收失败");
               }
           }
       }
  }

1 // 删除消息

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- (BOOL)removeRevokeMessageWithChatter:(NSString *)aChatter
                      conversationType:(EMConversationType)type
                             messageId:(NSString *)messageId{
     
    EMConversation *conversation = [[EMClient sharedClient].chatManager getConversation:aChatter type:type createIfNotExist:YES];
  [conversation deleteMessageWithId:messageId];
    return YES;
}

这样就好了，希望能帮到你们～

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