1.1 问题
Socket的英文原义是孔或者插座的意思,通常也称作套接字,用于描述IP地址和端口,是一个通信链的句柄,本案例使用第三方Socket编程框架AsyncSocket框架实现一个简易的聊天工具,并且能够进行文件传输,由于没有服务器本案例将服务器端和客户端写在一个程序中,如图-1所示:
![](http://pdf7.tarena.com.cn/tts8_source/ttsPage/IOS/ISD_V01/NETWORKING/DAY01/CASE/01/index.files/image001.png)
图-1
1.2 方案
首先创建一个SingleViewApplication应用,导入AsyncSocket框架。在Storyboard中搭建聊天界面,上方的Textfield控件用于输入接受端IP地址,中间TextView控件用于展示聊天记录,下方的TextView用于接受用户输入的聊天内容,右下角有一个发送按钮。将这三个控件分别关联成ViewController的输出口属性IPTF、chatRecordTV、chatTV。
接下来首先实现聊天功能,在ViewController中定义三个属性severSocket、clientSocket以及myNewSocket。在viewDidLoad方法中创建服务器端severSocket,将端口号设置为8000,委托对象设置为self。将发送按钮关联成viewController的动作方法send:,实现send:方法,创建客户端对象,获取聊天输入框的内容转化成NSData类型的数据发送出去。
然后ViewController遵守AsyncSocketDelegate协议,分别实现关于socket连接,数据传输以及数据读取的协议方法,更新显示聊天记录内容。
最后实现传输文件功能,传输文件时为了确定所传输文件的类型需要拼接一个消息头,将传输文件的类型、名称和大小保存到消息头里,通常传输数据的开始的100个字节是消息头。在sender:方法中增加拼接消息头的代码。
接受端在接收到文件数据时首先对消息头进行解析,获取到接收文件的类型、大小以及名称,然后再持续接受文件数据,接受完成后将文件保存到本地路径。
1.3 步骤
实现此案例需要按照如下步骤进行。
步骤一:搭建聊天界面
首先创建一个SingleViewApplication应用,导入AsyncSocket框架。在Storyboard中搭建聊天界面,上方的Textfield控件用于输入接受端IP地址,中间TextView控件用于展示聊天记录,下方的TextView用于接受用户输入的聊天内容,如图-2所示:
![](http://pdf7.tarena.com.cn/tts8_source/ttsPage/IOS/ISD_V01/NETWORKING/DAY01/CASE/01/index.files/image002.png)
图-2
然后将这三个控件分别关联成ViewController的输出口属性IPTF、chatRecordTV、chatTV,代码如下所示:
- @interface ViewController ()
- @property (weak, nonatomic) IBOutlet UITextField *IPTF;
- @property (weak, nonatomic) IBOutlet UITextView *chatRecordTV;
- @property (weak, nonatomic) IBOutlet UITextView *chatTV;
- @end
步骤二:实现聊天功能
首先在ViewController中定义三个属性severSocket、clientSocket以及myNewSocket,代码如下所示:
- @interface ViewController ()
- @property (nonatomic, strong)AsyncSocket *serverSocket;
- @property (nonatomic, strong)AsyncSocket *clientSocket;
- @property (nonatomic, strong)AsyncSocket *myNewSocket;
- @end
其次在viewDidLoad方法中创建服务器端severSocket,将端口号设置为8000,委托对象设置为self,代码如下所示:
- - (void)viewDidLoad {
- [super viewDidLoad];
- self.serverSocket = [[AsyncSocket alloc]initWithDelegate:self];
- [self.serverSocket acceptOnPort:8000 error:nil];
- }
将发送按钮关联成viewController的动作方法send:,实现send:方法,创建客户端对象,获取聊天输入框的内容转化成NSData类型的数据发送出去,代码如下所示:
- - (IBAction)send:(UIButton *)sender {
- [self.chatTV resignFirstResponder];
- //创建Socket客户端
- self.clientSocket = [[AsyncSocket alloc]initWithDelegate:self];
- [self.clientSocket connectToHost:self.IPTF.text onPort:8000 withTimeout:-1 error:nil];
- //将聊天输入框的内容转化为NSData
- NSData *data = [self.chatTV.text dataUsingEncoding:NSUTF8StringEncoding];
- //发送数据
- [self.clientSocket writeData:data withTimeout:-1 tag:0];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n我说:%@",self.chatRecordTV.text,self.chatTV.text];
- }
运行程序发现,点击聊天输入框弹出的键盘会挡住聊天输入框,因此需要在接受用户输入的时候屏幕界面上移,viewController遵守UITextFieldDelegate和UITextViewDelegate协议,当进入输入状况的时候屏幕界面上移,代码如下所示:
- -(BOOL)textViewShouldBeginEditing:(UITextView *)textView {
- [UIView beginAnimations:nil context:nil];
- [UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
- [UIView setAnimationDuration:0.2];
- self.view.center = CGPointMake(160, self.view.center.y-200);
- [UIView commitAnimations];
- return YES;
- }
添加一个单击手势。当单击屏幕或者点击发送按钮时键盘收回,屏幕界面恢复正常位置,代码如下所示:
- //点击发送按钮是
- - (IBAction)send:(UIButton *)sender {
- [self.chatTV resignFirstResponder];
- [UIView beginAnimations:nil context:nil];
- [UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
- [UIView setAnimationDuration:0.2];
- self.view.center = CGPointMake(160, point.y);
- [UIView commitAnimations];
- //创建Socket客户端
- self.clientSocket = [[AsyncSocket alloc]initWithDelegate:self];
- [self.clientSocket connectToHost:self.IPTF.text onPort:8000 withTimeout:-1 error:nil];
- //将聊天输入框的内容转化为NSData
- NSData *data = [self.chatTV.text dataUsingEncoding:NSUTF8StringEncoding];
- //发送数据
- [self.clientSocket writeData:data withTimeout:-1 tag:0];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n我说:%@",self.chatRecordTV.text,self.chatTV.text];
- }
- //单击屏幕时
- - (IBAction)resign:(UITapGestureRecognizer *)sender {
- if (self.view.center.y!=point.y) {
- [self.chatTV resignFirstResponder];
- [UIView beginAnimations:nil context:nil];
- [UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
- [UIView setAnimationDuration:0.2];
- self.view.center = point;
- [UIView commitAnimations];
- }
- }
最后ViewController遵守AsyncSocketDelegate协议,分别实现关于socket连接,数据传输以及数据读取的协议方法,代码如下所示:
- //当Socket接受一个连接的时候被调用
- -(void)onSocket:(AsyncSocket *)sock didAcceptNewSocket:(AsyncSocket *)newSocket{
- //将新接受的socket持有
- self.myNewSocket = newSocket;
- }
- //当Socket连接并准备读和写调用
- -(void)onSocket:(AsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port {
- //持续读取数据
- [self.myNewSocket readDataWithTimeout:-1 tag:0];
- }
- //当Socket读取数据时调用
- -(void)onSocket:(AsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag {
- NSString *chatStr = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n对方说:%@",self.chatRecordTV.text,chatStr];
- [self.myNewSocket readDataWithTimeout:-1 tag:0];
- }
- //持续发送数据
- -(void)onSocket:(AsyncSocket *)sock didWriteDataWithTag:(long)tag {
- NSLog(@"发送成功");
- [self.myNewSocket readDataWithTimeout:-1 tag:0];
- }
运行程序,聊天效果如图-3所示:
![](http://pdf7.tarena.com.cn/tts8_source/ttsPage/IOS/ISD_V01/NETWORKING/DAY01/CASE/01/index.files/image003.png)
图-3
步骤三:实现文件传输功能
首先定义三个属性用于记录传输文件的数据、名称和大小,代码如下所示:
- @property (strong,nonatomic) NSMutableData *allData;
- @property (nonatomic, copy)NSString *reciveFileName;
- @property (nonatomic, assign)int reciveFileLength;
文件传输需要拼接头文件,将传输文件的类型、大小和名称放进消息头里面,因此在sender:方法中增加拼接消息头的代码,本案例以路径开头区分是发送文件还是聊天,代码如下所示:
- - (IBAction)send:(UIButton *)sender {
- [self.chatTV resignFirstResponder];
- [UIView beginAnimations:nil context:nil];
- [UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
- [UIView setAnimationDuration:0.2];
- self.view.center = CGPointMake(160, point.y);
- [UIView commitAnimations];
- self.clientSocket = [[AsyncSocket alloc]initWithDelegate:self];
- [self.clientSocket connectToHost:self.IPTF.text onPort:8000 withTimeout:-1 error:nil];
- if (![self.chatTV.text hasPrefix:@"/Users"]) {
- NSData *data = [self.chatTV.text dataUsingEncoding:NSUTF8StringEncoding];
- [self.clientSocket writeData:data withTimeout:-1 tag:0];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n我说:%@",self.chatRecordTV.text,self.chatTV.text];
- }else {
- NSString *filePath = self.chatTV.text;
- NSData *fileData = [NSData dataWithContentsOfFile:filePath];
- //把头信息添加到文件Data的前面
- NSString *header = [NSString stringWithFormat:@"file&&%@&&%d",[filePath lastPathComponent],fileData.length];
- //把头字符串转成data
- NSData *headerData = [header dataUsingEncoding:NSUTF8StringEncoding];
- //把头替换进100个字节的data里面
- NSMutableData *sendAllData = [NSMutableData dataWithLength:100];
- [sendAllData replaceBytesInRange:NSMakeRange(0, headerData.length) withBytes:headerData.bytes];
- [sendAllData appendData:fileData];
- NSLog(@"%@",header);
- NSLog(@"SendLength = %d",sendAllData.length);
- [self.clientSocket writeData:sendAllData withTimeout:-1 tag:0];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n我说:%@正在发送",self.chatRecordTV.text,self.chatTV.text];
- }
- }
在读取数据的方法中首先获取消息头信息,如果传递过来的是文件则获取到传输文件的类型、大小和名称,持续读取文件数据,将文件保存到本地路径,接受完成更新聊天记录,代码如下所示:
- -(void)onSocket:(AsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag {
- if (data.length>=100) {
- NSData *headerData = [data subdataWithRange:NSMakeRange(0, 100)];
- NSString *headerStr = [[NSString alloc]initWithData:headerData encoding:NSUTF8StringEncoding];
- if (headerStr&& [headerStr componentsSeparatedByString:@"&&"].count==3) {
- isFile = YES;
- }
- }
- if (isFile == NO) {
- NSString *chatStr = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n对方说:%@",self.chatRecordTV.text,chatStr];
- }
- if (isFile==YES) {
- if (data.length>=100) {
- NSData *headerData = [data subdataWithRange:NSMakeRange(0, 100)];
- NSString *headerStr = [[NSString alloc]initWithData:headerData encoding:NSUTF8StringEncoding];
- if (headerStr&& [headerStr componentsSeparatedByString:@"&&"].count==3) {
- NSArray *headers = [headerStr componentsSeparatedByString:@"&&"];
- NSString *type = [headers objectAtIndex:0];
- if ([type isEqualToString:@"file"]) {
- self.reciveFileName = [headers objectAtIndex:1];
- self.reciveFileLength = [[headers objectAtIndex:2] intValue];
- NSData *subFileData = [data subdataWithRange:NSMakeRange(100, data.length-100)];
- if (!self.allData) {
- self.allData = [NSMutableData data];
- }
- [self.allData appendData:subFileData];
- }
- }else {//没有消息头的情况下
- [self.allData appendData:data];
- }
- }else {//没有消息头的情况下
- [self.allData appendData:data];
- }
- NSLog(@"%d,%d",self.allData.length,self.reciveFileLength);
- if (self.allData.length == self.reciveFileLength ) {
- NSLog(@"接受完成");
- NSString *filePath = [@"/Users/Vivian/Documents" stringByAppendingPathComponent:self.reciveFileName];
- [self.allData writeToFile:filePath atomically:YES];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n对方说:成功接收文件%@",self.chatRecordTV.text,self.reciveFileName];
- self.allData = nil;
- isFile = NO;
- }
- if (isFile == YES) {
- //如果有数据能够持续接受
- [self.myNewSocket readDataWithTimeout:-1 tag:0];
- }
- }
- }
运行程序,传输文件效果如图-4所示:
![](http://pdf7.tarena.com.cn/tts8_source/ttsPage/IOS/ISD_V01/NETWORKING/DAY01/CASE/01/index.files/image004.png)
图-4
1.4 完整代码
本案例中,ViewController.m文件中的完整代码如下所示:
- #import "ViewController.h"
- @interface ViewController () <AsyncSocketDelegate,UITextFieldDelegate,UITextViewDelegate> {
- BOOL isFile;
- CGPoint point;
- }
- @property (weak, nonatomic) IBOutlet UITextField *IPTF;
- @property (weak, nonatomic) IBOutlet UITextView *chatRecordTV;
- @property (weak, nonatomic) IBOutlet UITextView *chatTV;
- @property (nonatomic, strong)AsyncSocket *serverSocket;
- @property (nonatomic, strong)AsyncSocket *clientSocket;
- @property (nonatomic, strong)AsyncSocket *myNewSocket;
- @property (strong,nonatomic) NSMutableData *allData;
- @property (nonatomic, copy)NSString *reciveFileName;
- @property (nonatomic, assign)int reciveFileLength;
- @end
- @implementation ViewController
- - (void)viewDidLoad {
- [super viewDidLoad];
- self.serverSocket = [[AsyncSocket alloc]initWithDelegate:self];
- [self.serverSocket acceptOnPort:8000 error:nil];
- point = self.view.center;
- self.allData = [NSMutableData data];
- isFile = NO;
- }
- -(void)onSocket:(AsyncSocket *)sock didAcceptNewSocket:(AsyncSocket *)newSocket{
- //将新接受的socket持有
- self.myNewSocket = newSocket;
- }
- -(void)onSocket:(AsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port {
- [self.myNewSocket readDataWithTimeout:-1 tag:0];
- }
- -(void)onSocket:(AsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag {
- if (data.length>=100) {
- NSData *headerData = [data subdataWithRange:NSMakeRange(0, 100)];
- NSString *headerStr = [[NSString alloc]initWithData:headerData encoding:NSUTF8StringEncoding];
- if (headerStr&& [headerStr componentsSeparatedByString:@"&&"].count==3) {
- isFile = YES;
- }
- }
- if (isFile == NO) {
- NSString *chatStr = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n对方说:%@",self.chatRecordTV.text,chatStr];
- }
- if (isFile==YES) {
- if (data.length>=100) {
- NSData *headerData = [data subdataWithRange:NSMakeRange(0, 100)];
- NSString *headerStr = [[NSString alloc]initWithData:headerData encoding:NSUTF8StringEncoding];
- if (headerStr&& [headerStr componentsSeparatedByString:@"&&"].count==3) {
- NSArray *headers = [headerStr componentsSeparatedByString:@"&&"];
- NSString *type = [headers objectAtIndex:0];
- if ([type isEqualToString:@"file"]) {
- self.reciveFileName = [headers objectAtIndex:1];
- self.reciveFileLength = [[headers objectAtIndex:2] intValue];
- NSData *subFileData = [data subdataWithRange:NSMakeRange(100, data.length-100)];
- if (!self.allData) {
- self.allData = [NSMutableData data];
- }
- [self.allData appendData:subFileData];
- }
- }else {//没有消息头的情况下
- [self.allData appendData:data];
- }
- }else {//没有消息头的情况下
- [self.allData appendData:data];
- }
- NSLog(@"%d,%d",self.allData.length,self.reciveFileLength);
- if (self.allData.length == self.reciveFileLength ) {
- NSLog(@"接受完成");
- NSString *filePath = [@"/Users/Vivian/Documents" stringByAppendingPathComponent:self.reciveFileName];
- [self.allData writeToFile:filePath atomically:YES];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n对方说:成功接收文件%@",self.chatRecordTV.text,self.reciveFileName];
- self.allData = nil;
- isFile = NO;
- }
- if (isFile == YES) {
- //如果有数据能够持续接受
- [self.myNewSocket readDataWithTimeout:-1 tag:0];
- }
- }
- }
- -(void)onSocket:(AsyncSocket *)sock didWriteDataWithTag:(long)tag {
- NSLog(@"发送成功");
- [self.myNewSocket readDataWithTimeout:-1 tag:0];
- }
- -(BOOL)textViewShouldBeginEditing:(UITextView *)textView {
- [UIView beginAnimations:nil context:nil];
- [UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
- [UIView setAnimationDuration:0.2];
- self.view.center = CGPointMake(160, self.view.center.y-200);
- [UIView commitAnimations];
- return YES;
- }
- - (IBAction)send:(UIButton *)sender {
- [self.chatTV resignFirstResponder];
- [UIView beginAnimations:nil context:nil];
- [UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
- [UIView setAnimationDuration:0.2];
- self.view.center = CGPointMake(160, point.y);
- [UIView commitAnimations];
- self.clientSocket = [[AsyncSocket alloc]initWithDelegate:self];
- [self.clientSocket connectToHost:self.IPTF.text onPort:8000 withTimeout:-1 error:nil];
- if (![self.chatTV.text hasPrefix:@"/Users"]) {
- NSData *data = [self.chatTV.text dataUsingEncoding:NSUTF8StringEncoding];
- [self.clientSocket writeData:data withTimeout:-1 tag:0];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n我说:%@",self.chatRecordTV.text,self.chatTV.text];
- }else {
- NSString *filePath = self.chatTV.text;
- NSData *fileData = [NSData dataWithContentsOfFile:filePath];
- //把头信息添加到文件Data的前面
- NSString *header = [NSString stringWithFormat:@"file&&%@&&%d",[filePath lastPathComponent],fileData.length];
- //把头字符串转成data
- NSData *headerData = [header dataUsingEncoding:NSUTF8StringEncoding];
- //把头替换进100个字节的data里面
- NSMutableData *sendAllData = [NSMutableData dataWithLength:100];
- [sendAllData replaceBytesInRange:NSMakeRange(0, headerData.length) withBytes:headerData.bytes];
- [sendAllData appendData:fileData];
- NSLog(@"%@",header);
- NSLog(@"SendLength = %d",sendAllData.length);
- [self.clientSocket writeData:sendAllData withTimeout:-1 tag:0];
- self.chatRecordTV.text = [NSString stringWithFormat:@"%@\n我说:%@正在发送",self.chatRecordTV.text,self.chatTV.text];
- }
- }
- - (IBAction)done:(UITextField *)sender {
- [self.IPTF resignFirstResponder];
- }
- - (IBAction)resign:(UITapGestureRecognizer *)sender {
- if (self.view.center.y!=point.y) {
- [self.chatTV resignFirstResponder];
- [UIView beginAnimations:nil context:nil];
- [UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
- [UIView setAnimationDuration:0.2];
- self.view.center = point;
- [UIView commitAnimations];
- }
- }
- @end