iOS XMPP Framework 07 - 收发消息 下

YDConversationViewController

YDConversationViewController的目的是现实用户和其好友之间的会话信息。用户发送的消息和接收到得消息分别位于UITableView的两侧。

添加行高和最多显示的聊天行数定义到YDDefinitions.h

//YDConversationViewController#define lineHeight 16.0f#define maxChatLines 4

创建继承于UIViewController的YDConversationViewController，YDConversationViewController.h

#import <UIKit/UIKit.h>@interface YDConversationViewController : UIViewController- (void)showConversationForJIDString:(NSString *)jidString;@end

YDConversationViewController.m，首先import需要的头文件，然后声明本类遵从UITableViewDataSource，UITableViewDelegate和UITextViewDelegate歇息。最后创建程序需要的一些成员变量。

#import "YDConversationViewController.h"#import "DDLog.h"#import "DDTTYLogger.h"#import <CoreData/CoreData.h>#import "YDAppDelegate.h"#if DEBUGstatic const int ddLogLevel = LOG_LEVEL_VERBOSE;#elsestatic const int ddLogLevel = LOG_LEVEL_INFO;#endif@interface YDConversationViewController ()<UITableViewDataSource,UITableViewDelegate,UITextViewDelegate>{    float prevLines;    UIButton *sendButton;}@property (nonatomic,strong) NSString *cleanName;@property (nonatomic,strong) NSString *conversationJidString;@property (nonatomic,strong) UITableView *mtableView;@property (nonatomic,strong) NSMutableArray* chats;@property (nonatomic,strong) UILabel *statusLabel;@property (nonatomic,strong) UIView *sendView;@property (nonatomic,strong) UITextView *msgText;@end

监听kNewMessage和kChatStatus消息。

#pragma mark view appearance-(void)viewWillAppear:(BOOL)animated{    //Add Observer    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(newMessageReceived:) name:kNewMessage  object:nil];    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(statusUpdateReceived:) name:kChatStatus  object:nil];}-(void)viewWillDisappear:(BOOL)animated{    //Remove notifications    [[NSNotificationCenter defaultCenter] removeObserver:self name:kChatStatus  object:nil];    [[NSNotificationCenter defaultCenter] removeObserver:self name:kNewMessage object:nil];    }

loadData方法，在viewDidLoad和收到新消息时调用：

-(void)loadData{    if (self.chats)        self.chats =nil;    self.chats = [[NSMutableArray alloc]init];    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Chat"                                              inManagedObjectContext:[self appDelegate].managedObjectContext];    NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];    [fetchRequest setEntity:entity];    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"jidString == %@",self.conversationJidString];    [fetchRequest setPredicate:predicate];    NSError *error=nil;    NSArray *fetchedObjects = [[self appDelegate].managedObjectContext executeFetchRequest:fetchRequest error:&error];    for (NSManagedObject *obj in fetchedObjects)    {        [self.chats addObject:obj];        //Since they are now visible set the isNew to NO        Chat *thisChat = (Chat *)obj;        if ([thisChat.isNew  boolValue])            thisChat.isNew = [NSNumber numberWithBool:NO];    }    //Save changes    error = nil;    if (![[self appDelegate].managedObjectContext save:&error])    {        NSLog(@"error saving");    }    //reload the table view    [self.mtableView reloadData];    [self scrollToBottomAnimated:YES];}

sendMessage方法，当用户完成输入后，点击发送按钮时执行，将数据发送出去。

#pragma mark send message-(IBAction)sendMessage:(id)sender{    NSString *messageStr = self.msgText.text;    if([messageStr length] > 0)    {        //send chat message                NSXMLElement *body = [NSXMLElement elementWithName:@"body"];        [body setStringValue:messageStr];        NSXMLElement *message = [NSXMLElement elementWithName:@"message"];        [message addAttributeWithName:@"type" stringValue:@"chat"];        [message addAttributeWithName:@"to" stringValue:self.conversationJidString];        [message addChild:body];        NSXMLElement *status = [NSXMLElement elementWithName:@"active" xmlns:@"http://jabber.org/protocol/chatstates"];        [message addChild:status];                [[self appDelegate].xmppStream sendElement:message];        // We need to put our own message also in CoreData of course and reload the data        Chat *chat = [NSEntityDescription                      insertNewObjectForEntityForName:@"Chat"                      inManagedObjectContext:[self appDelegate].managedObjectContext];        chat.messageBody = messageStr;        chat.messageDate = [NSDate date];        chat.hasMedia=[NSNumber numberWithBool:NO];        chat.isNew=[NSNumber numberWithBool:NO];        chat.messageStatus=@"send";        chat.direction = @"OUT";                chat.groupNumber=@"";        chat.isGroupMessage=[NSNumber numberWithBool:NO];        chat.jidString =  self.conversationJidString;                NSError *error = nil;        if (![[self appDelegate].managedObjectContext save:&error])        {            NSLog(@"error saving");        }    }    self.msgText.text=@"";    if ([self.msgText isFirstResponder])        [self.msgText resignFirstResponder ];        //Reload our data    [self loadData];    //Restore the Screen    [self showFullTableView];    }

用户输入时，发送composing消息：

#pragma mark UITextView Delegate-(void)textViewDidChange:(UITextView *)textView{        UIFont* systemFont = [UIFont boldSystemFontOfSize:12];    int width = 185.0, height = 10000.0;    NSMutableDictionary *atts = [[NSMutableDictionary alloc] init];    [atts setObject:systemFont forKey:NSFontAttributeName];        CGRect textSize = [self.msgText.text boundingRectWithSize:CGSizeMake(width, height)                                                      options:NSStringDrawingUsesLineFragmentOrigin                                                   attributes:atts                                                      context:nil];    float textHeight = textSize.size.height;    float lines = textHeight / lineHeight;    // NSLog(@"textViewDidChange h: %0.f  lines %0.f ",textHeight,lines);    if (lines >=4)        lines=4;    if (lines < 1.0)        lines = 1.0;    //Send your chat state    NSXMLElement *message = [NSXMLElement elementWithName:@"message"];    [message addAttributeWithName:@"type" stringValue:@"chat"];    [message addAttributeWithName:@"to" stringValue:self.conversationJidString];    NSXMLElement *status = [NSXMLElement elementWithName:@"composing" xmlns:@"http://jabber.org/protocol/chatstates"];    [message addChild:status];    [[self appDelegate].xmppStream sendElement:message];        if (prevLines!=lines)        [self shortenTableView];        prevLines=lines;}-(void)textViewDidBeginEditing:(UITextView *)textView{ [UIView beginAnimations:@"moveView" context:nil];    [UIView setAnimationDuration:0.3];    self.sendView.frame = CGRectMake(0,ScreenHeight-270,ScreenWidth,56);    [UIView commitAnimations];    [self shortenTableView];    [self.msgText becomeFirstResponder];    //Send your chat state    NSXMLElement *message = [NSXMLElement elementWithName:@"message"];    [message addAttributeWithName:@"type" stringValue:@"chat"];    [message addAttributeWithName:@"to" stringValue:self.conversationJidString];    NSXMLElement *status = [NSXMLElement elementWithName:@"composing" xmlns:@"http://jabber.org/protocol/chatstates"];    [message addChild:status];    [[self appDelegate].xmppStream sendElement:message];    }

cell方法

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{    static NSString *CellIdentifier = @"Cell";        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];    if (cell == nil)    {        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault                                      reuseIdentifier:CellIdentifier];    }    Chat* chat = [self.chats objectAtIndex:indexPath.row];    UIFont* systemFont = [UIFont boldSystemFontOfSize:12];    int width = 185.0, height = 10000.0;    NSMutableDictionary *atts = [[NSMutableDictionary alloc] init];    [atts setObject:systemFont forKey:NSFontAttributeName];        CGRect textSize = [self.msgText.text boundingRectWithSize:CGSizeMake(width, height)                                                      options:NSStringDrawingUsesLineFragmentOrigin                                                   attributes:atts                                                      context:nil];    float textHeight = textSize.size.height;        //Body    UITextView *body = [[UITextView alloc] initWithFrame:CGRectMake(70,3,240,textHeight+10)];    body.backgroundColor = [UIColor clearColor];    body.editable = NO;    body.scrollEnabled = NO;    body.backgroundColor=[UIColor clearColor];    body.textColor=[UIColor blackColor];    body.textAlignment=NSTextAlignmentLeft;    [body setFont:[UIFont  boldSystemFontOfSize:12]];    body.text = chat.messageBody;    [body sizeToFit];    //SenderLabel    UILabel *senderLabel = [[UILabel alloc] initWithFrame:CGRectMake(10,textHeight +10 ,300,20)];    senderLabel.backgroundColor=[UIColor clearColor];    senderLabel.font = [UIFont systemFontOfSize:12];    senderLabel.textColor=[UIColor blackColor];    senderLabel.textAlignment=NSTextAlignmentLeft;    UIImage *bgImage;    float senderStartX;    if ([chat.direction isEqualToString:@"IN"])    { // left aligned        bgImage = [[UIImage imageNamed:@"leftballoon.png"] stretchableImageWithLeftCapWidth:0  topCapHeight:15];        body.frame=CGRectMake(10,3,240.0,textHeight+10 );        senderLabel.frame=CGRectMake(19,textHeight+15,250,13);        senderLabel.text= [NSString stringWithFormat:@"%@: %@",self.cleanName,[YDHelper dayLabelForMessage:chat.messageDate]];        senderStartX=19;    }    else    {        //right aligned        bgImage = [[UIImage imageNamed:@"rightballoonred.png"] stretchableImageWithLeftCapWidth:0  topCapHeight:15];        body.frame=CGRectMake(45,3,240.0,textHeight+10);        senderLabel.frame=CGRectMake(55,textHeight+15,250,13);        senderLabel.text= [NSString stringWithFormat:@"You %@" ,[YDHelper dayLabelForMessage:chat.messageDate]];        senderStartX=55;    }    CGFloat heightForThisCell =  textHeight + 40;    UIImageView *balloonHolder = [[UIImageView alloc] initWithFrame:CGRectMake(0,5,320,textHeight+35 )];    balloonHolder.image = bgImage;    balloonHolder.backgroundColor=[UIColor clearColor];    //Create the content holder    UIView *cellContentView = [[UIView alloc] initWithFrame:CGRectMake(0,5,320,heightForThisCell)];    [cellContentView addSubview:balloonHolder];    [cellContentView addSubview:body];    [cellContentView addSubview:senderLabel];    cell.backgroundView = cellContentView;    return cell;}