IOS中如何显示开发者服务器上的昵称和头像

无论是IOS还是安卓，集成环信SDK遇到的第一个问题，就是如何显示自有用户体系中的昵称和头像。运行环信的demo app，注册用户是直接使用环信ID(username)作为用户名，但是在我们实际运用中，需要将自有用户体系的UserId生成GUID作为环信ID（username）【参考：http://docs.easemob.com/im/100serverintegration/20users】，这时候如果不经过处理，则会显示如下界面：


 
那么如何处理，才能显示正确的用户昵称和头像呢？
其实官方已经提供有解决方案了，只不过没有给出示例代码而已。
http://docs.easemob.com/im/490integrationcases/10nickname
 
引用一下关键文字：

方法二：从消息扩展中获取昵称和头像

昵称和头像的获取：把用户基本的昵称和头像的URL放到消息的扩展中，通过消息传递给接收方，当收到一条消息时，则能通过消息的扩展得到发送者的昵称和头像URL，然后保存到本地数据库和缓存。当显示昵称和头像时，请从本地或者缓存中读取，不要直接从消息中把赋值拿给界面（否则当用户昵称改变后，同一个人会显示不同的昵称）。

昵称和头像的更新：当扩展消息中的昵称和头像 URI 与当前本地数据库和缓存中的相应数据不同的时候，需要把新的昵称保存到本地数据库和缓存，并下载新的头像并保存到本地数据库和缓存。

 
没错，官方提供了两种思路，鉴于项目的实际情况，我选择了【方法二】。
于是，无论安卓，还是IOS，我们都是这样处理的：
【1】.APP间传递用户属性信息：发送(文本、图片...)消息时，要在消息扩展（message.ext）中附带当前用户的属性信息；
【2】.本地缓存用户信息：在接收消息的回调函数里，读取消息扩展（message.ext）里用户属性（键值对）信息；如果本地缓存（sqlite）不存在该用户，则新增缓存记录，如果存在，则更新记录；（用户登录或注册成功后，也要更新用户缓存信息）
【3】.获取用户属性信息：在需要显示昵称的地方，根据环信ID，读取sqlite缓存数据，获取用户昵称和头像；
用户属性信息：ChatUserId（环信ID），ChatUserNick（用户昵称）, ChatUserPic（用户头像，完整的url地址）；

 
IOS关键代码：

// 环信聊天用的昵称和头像（发送聊天消息时，要附带这3个属性）

#define kChatUserId @"ChatUserId"// 环信账号

#define kChatUserNick @"ChatUserNick"

#define kChatUserPic @"ChatUserPic"

 ChatUserCacheInfo是环信用户信息缓存管理类
ChatUserCacheInfo.h

#import <Foundation/Foundation.h>


@interface ChatUserCacheInfo : NSObject

@property(nonatomic,copy)NSString* Id;

@property(nonatomic,copy)NSString* NickName;

@property(nonatomic,copy)NSString* AvatarUrl;

@end



@interface ChatUserCacheUtil : NSObject


+(void)saveInfo:(NSString *)openId

              imgId:(NSString*)imgId

           nickName:(NSString*)nickName;


+(void)saveDict:(NSDictionary *)userinfo;


+(void)saveModel:(UserApiModel*)user;


+(ChatUserCacheInfo*)queryById:(NSString *)userid;


@end

ChatUserCacheUtil.m

#import "ChatUserCacheUtil.h"

#import "FMDB.h"


#define DBNAME @"cache_data.db"


@implementation ChatUserCacheInfo


@end


@implementation ChatUserCacheUtil


+(void)createTable:(FMDatabase *)db

{

    if ([db open]) {

        if (![db tableExists :@"userinfo"]) {

            if ([db executeUpdate:@"create table userinfo (userid text, username text, userimage text)"]) {

                NSLog(@"create table success");

            }else{

                NSLog(@"fail to create table");

            }

        }else {

             NSLog(@"table is already exist");

        }

    }else{

        NSLog(@"fail to open");

    }

}


+ (void)clearTableData:(FMDatabase *)db

{

    if ([db executeUpdate:@"DELETE FROM userinfo"]) {

        NSLog(@"clear successed");

    }else{

        NSLog(@"fail to clear");

    }

}


+(FMDatabase*)getDB{

    NSString *docsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];

    NSString *dbPath   = [docsPath stringByAppendingPathComponent:DBNAME];

    FMDatabase *db     = [FMDatabase databaseWithPath:dbPath];
[self createTable:db];

    return db;

}


+(void)saveModel:(UserApiModel*)user{
[ChatUserCacheUtil saveInfo:user.EaseMobUserName imgId:user.HeadImg nickName:user.Username];

}


+(void)saveInfo:(NSString *)openId

              imgId:(NSString*)imgId

           nickName:(NSString*)nickName{

    NSMutableDictionary *extDic = [NSMutableDictionary dictionary];
[extDic setValue:openId forKey:kChatUserId];
[extDic setValue:@"[url=http://img.baidu.com"]http://img.baidu.com/"[/url]+imgId   forKey:kChatUserPic];//完整图片路径"http://img.baidu.com/1234"。如果imgId是相对路径，那完整路径就是类似"http://img.baidu.com/abc.jpg"
[extDic setValue:nickName forKey:kChatUserNick];
[ChatUserCacheUtil saveDict:extDic];

}


+(void)saveDict:(NSDictionary *)userinfo{

    FMDatabase *db     = [self getDB];


    NSString *userid = [userinfo objectForKey:kChatUserId];

    if ([db executeUpdate:@"DELETE FROM userinfo where userid = ?", userid]) {

        DLog(@"删除成功");

    }else{

        DLog(@"删除失败");

    }

    NSString *username = [userinfo objectForKey:kChatUserNick];

    NSString *userimage = [userinfo objectForKey:kChatUserPic];

    if ([db executeUpdate:@"INSERT INTO userinfo (userid, username, userimage) VALUES (?, ?, ?)", userid,username,userimage]) {

        DLog(@"插入成功");

    }else{

        DLog(@"插入失败");

    }


//    NSLog(@"%d: %@", [db lastErrorCode], [db lastErrorMessage]);

    FMResultSet *rs = [db executeQuery:@"SELECT userid, username, userimage FROM userinfo where userid = ?",userid];

    if ([rs next]) {

        NSString *userid = [rs stringForColumn:@"userid"];

        NSString *username = [rs stringForColumn:@"username"];

        NSString *userimage = [rs stringForColumn:@"userimage"];

        DLog(@"查询一个 %@ %@ %@",userid,username,userimage);

    }


    rs = [db executeQuery:@"SELECT userid, username, userimage FROM userinfo"];

    while ([rs next]) {

        NSString *userid = [rs stringForColumn:@"userid"];

        NSString *username = [rs stringForColumn:@"username"];

        NSString *userimage = [rs stringForColumn:@"userimage"];

        DLog(@"查询所有 %@ %@ %@",userid,username,userimage);

    }
[rs close];

//    NSLog(@"%d: %@", [db lastErrorCode], [db lastErrorMessage]);
[db close];


}


+(ChatUserCacheInfo*)queryById:(NSString *)userid{

    FMDatabase *db     = [self getDB];

    if ([db open]) {

        FMResultSet *rs = [db executeQuery:@"SELECT userid, username, userimage FROM userinfo where userid = ?",userid];

        if ([rs next]) {


            ChatUserCacheInfo *userInfo = [[ChatUserCacheInfo alloc] init];


            userInfo.Id = [rs stringForColumn:@"userid"];

            userInfo.NickName = [rs stringForColumn:@"username"];

            userInfo.AvatarUrl = [rs stringForColumn:@"userimage"];

            DLog(@"查询一个 %@",userInfo);

            return userInfo;

        }else{

            return nil;

        }

    }else{

        return nil;

    }

}



@end

首先要在用户登录或注册成功后，返回用户登录信息时，缓存一下用户信息：

@protocol UserApiModel <NSObject>


@end


@interface UserApiModel : BaseJSONModel

@property(nonatomic, assign)int Id;

@property(nonatomic, copy)NSString *Username;

@property(nonatomic, copy)NSString *Email;

@property(nonatomic, copy)NSString *HeadImg;

@property(nonatomic, copy)NSString *EaseMobUserName;

@property(nonatomic, copy)NSString *EaseMobPassword;

@end


// 登录成功后返回用户model，需要为环信聊天窗口缓存用户信息
[ChatUserCacheUtil saveModel:user];

然后在接收环信消息的回调函数里保存用户信息，HsMainViewController.m是我们项目的主框架，我们在这里写了回调函数，无论群聊还是单聊消息，都会调用这里：

// 收到消息回调

-(void)	didReceiveMessage:(EMMessage *)message

{
[ChatUserCacheUtil saveDict:message.ext];


    BOOL needShowNotification = (message.messageType != eMessageTypeChat) ? [self needShowNotification:message.conversationChatter] : YES;

    if (needShowNotification) {

#if !TARGET_IPHONE_SIMULATOR


        BOOL isAppActivity = [[UIApplication sharedApplication] applicationState] == UIApplicationStateActive;

        if (!isAppActivity) {
[self showNotificationWithMessage:message];

        }else {
[self playSoundAndVibration];

        }

#endif

    }

}

环信页面主要是在ChatViewController和ConversationListViewController里显示用户对话，所以我们要在这两个页面里从缓存取用户头像和昵称，先从ChatViewController开始：

- (id<IMessageModel>)messageViewController:(EaseMessageViewController *)viewController

                           modelForMessage:(EMMessage *)message

{

    id<IMessageModel> model = [[EaseMessageModel alloc] initWithMessage:message];


    ChatUserCacheInfo *userinfo = [ChatUserCacheUtil queryById:model.nickname];

    if (userinfo != nil) {

        model.nickname = userinfo.NickName;

        model.avatarURLPath = userinfo.AvatarUrl;

    }


    model.avatarImage = [UIImage imageNamed:@"EaseUIResource.bundle/user"];

    model.failImageName = @"imageDownloadFail";


    return model;

}

然后是ConversationListViewController：

#pragma mark - EaseConversationListViewControllerDataSource


- (id<IConversationModel>)conversationListViewController:(EaseConversationListViewController *)conversationListViewController

                                    modelForConversation:(EMConversation *)conversation

{

    EaseConversationModel *model = [[EaseConversationModel alloc] initWithConversation:conversation];

    if (model.conversation.conversationType == eConversationTypeChat) {

        ChatUserCacheInfo *userinfo = [ChatUserCacheUtil queryById:model.conversation.chatter];

        if (userinfo != nil) {

            model.title = userinfo.NickName;

            model.avatarURLPath = userinfo.AvatarUrl;

        }

        model.avatarImage = PlaceholderImgChatUser;

    } else if (model.conversation.conversationType == eConversationTypeGroupChat) {

        // 此处省略100行代码........

    }

}

最后，为了让另外一个客户端也能正确显示头像和昵称，app发送消息时，要在消息扩展里附带用户信息，代码写在EaseSDKHelper.m里：

// 重新消息扩展组织

+(NSMutableDictionary*)reGetMessageExt:(NSDictionary *)messageExt{

    NSMutableDictionary *extDic = [NSMutableDictionary dictionaryWithDictionary:messageExt];
[extDic setValue:[SettingData share].UserChatId forKey:kChatUserId];
[extDic setValue:[SettingData share].UserHeadImg.ServerThumbUrlStr forKey:kChatUserPic];
[extDic setValue:[SettingData share].UserName forKey:kChatUserNick];

    return extDic;

}


+ (EMMessage *)sendTextMessage:(NSString *)text

                            to:(NSString *)toUser

                   messageType:(EMMessageType)messageType

             requireEncryption:(BOOL)requireEncryption

                    messageExt:(NSDictionary *)messageExt


{

    // 表情映射。

    NSString *willSendText = [EaseConvertToCommonEmoticonsHelper convertToCommonEmoticons:text];

    EMChatText *textChat = [[EMChatText alloc] initWithText:willSendText];

    EMTextMessageBody *body = [[EMTextMessageBody alloc] initWithChatObject:textChat];

    EMMessage *message = [[EMMessage alloc] initWithReceiver:toUser bodies:[NSArray arrayWithObject:body]];

    message.requireEncryption = requireEncryption;

    message.messageType = messageType;


    message.ext = [self reGetMessageExt:messageExt];

    EMMessage *retMessage = [[EaseMob sharedInstance].chatManager asyncSendMessage:message

                                                                          progress:nil];


    return retMessage;

}



+ (EMMessage *)sendImageMessageWithImage:(UIImage *)image

                                      to:(NSString *)to

                             messageType:(EMMessageType)messageType

                       requireEncryption:(BOOL)requireEncryption

                              messageExt:(NSDictionary *)messageExt

                                progress:(id<IEMChatProgressDelegate>)progress

{

    return [self sendImageMessageWithImage:image to:to messageType:messageType requireEncryption:requireEncryption messageExt:messageExt quality:0.6 progress:progress];

}


+ (EMMessage *)sendImageMessageWithImage:(UIImage *)image

                                      to:(NSString *)to

                             messageType:(EMMessageType)messageType

                       requireEncryption:(BOOL)requireEncryption

                              messageExt:(NSDictionary *)messageExt

                                 quality:(float)quality

                                progress:(id<IEMChatProgressDelegate>)progress

{

    // 此处省略9行代码....


    message.ext = [self reGetMessageExt:messageExt];

    EMMessage *retMessage = [[EaseMob sharedInstance].chatManager asyncSendMessage:message

                                                                          progress:progress];


    return retMessage;

}


+ (EMMessage *)sendVoiceMessageWithLocalPath:(NSString *)localPath

                                    duration:(NSInteger)duration

                                          to:(NSString *)to

                                 messageType:(EMMessageType)messageType

                           requireEncryption:(BOOL)requireEncryption

                                  messageExt:(NSDictionary *)messageExt

                                    progress:(id<IEMChatProgressDelegate>)progress

{

    // 此处省略4行代码....


    message.ext = [self reGetMessageExt:messageExt];

    EMMessage *retMessage = [[EaseMob sharedInstance].chatManager asyncSendMessage:message

                                                                          progress:progress];


    return retMessage;

}


+ (EMMessage *)sendVideoMessageWithURL:(NSURL *)url

                                    to:(NSString *)to

                           messageType:(EMMessageType)messageType

                     requireEncryption:(BOOL)requireEncryption

                            messageExt:(NSDictionary *)messageExt

                              progress:(id<IEMChatProgressDelegate>)progress

{

    // 此处省略4行代码....


    message.ext = [self reGetMessageExt:messageExt];

    EMMessage *retMessage = [[EaseMob sharedInstance].chatManager asyncSendMessage:message

                                                                          progress:progress];


    return retMessage;

}


+ (EMMessage *)sendFileMessage:(EMChatFile *)chatFile

                                          to:(NSString *)to

                                 messageType:(EMMessageType)messageType

                           requireEncryption:(BOOL)requireEncryption

                                  messageExt:(NSDictionary *)messageExt

                                    progress:(id<IEMChatProgressDelegate>)progress

{

    // 此处省略4行代码....


    message.ext = [self reGetMessageExt:messageExt];

    EMMessage *retMessage = [[EaseMob sharedInstance].chatManager asyncSendMessage:message

                                                                          progress:progress];


    return retMessage;

}

有不当之处，欢迎指正~~谢谢。QQ：364223587
 
以上代码为SDK V2版本，如果集成的是V3版本，请移步源码：
http://git.oschina.net/markies/ChatDemo-UI3.00-Simple
思路其实跟V2差不多，最大区别V3的回调方法didReceiveMessages比V2多了个【s】。

ChatUserCacheUtil我已经重命名为：UserCacheManager
 

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