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) {
// 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"];
}
}
}
// 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
- (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，就是别人撤回后在当前聊天界面的刷新没做好，你们自己做一下。
是不是有点坑 ，我也觉得，但是最起码能给你们一些方向，就将就的看下去吧 ，嘟嘟嘟嘟。。
你们要有好方法告诉我～
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
- (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;
}
感觉我做的很粗糙，但是希望能帮到你们～