iOS中UDP的使用

//

//  ViewController.m

//  UDPDemo

//

//  Created by qianfeng01 on 15-8-13.

//  Copyright (c) 2015年 zg. All rights reserved.

//



#import "ViewController.h"

#import "AsyncUdpSocket.h"

#import "ZCScreenShot.h"

#define STU 1



@interface ViewController ()<AsyncUdpSocketDelegate>

{

    //建立socket

    AsyncUdpSocket *sendSocket;

    AsyncUdpSocket *serverSocket;

    

    //教师端须要一个label，每隔1秒，改变一下数字

    UILabel *numberLabel;

    

    //学生端。须要一个imageView,显示教师端发送过来的数据

    UIImageView *imageView;

    //须要一个宏定义来区分学生端和教师端，一键转换

    

}

@property (nonatomic,strong) NSMutableArray *ipArray;



@end



@implementation ViewController



- (void)viewDidLoad {

    [super viewDidLoad];



    /**

     *  程序分为学生端和教师端。教师端负责对全部接入程序的学生发送截图图片，学生端接受数据的时候。在imageview上显示

      

        学生端程序启动的时候，须要向教师端发送一个数据。也就是签到，这样教师端能够获得学生端的IP地址。进行数据转发

     

        须要的是：截屏函数仅仅对普通的ui有效。可是无法获取到视频截屏，假设要进行视频截屏。须要使用opengl来获取GL的信息，再进行渲染

     */

    self.ipArray = [NSMutableArray arrayWithCapacity:0];

    [self createView];

    [self createSocket];

    

    if (STU) {

        //假设是学生，程序启动向教师端发送一个数据

        [sendSocket sendData:[@"签到！

" dataUsingEncoding:NSUTF8StringEncoding] toHost:@"10.8.155.36" port:5678 withTimeout:-1 tag:100];

    }else{

        [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(timerClick) userInfo:nil repeats:YES];

    }

}



- (void)timerClick{

    

    if (self.ipArray.count == 0) {

        return;

    }

    

    //设置label的背景颜色

    float r = arc4random()%256/255.0;

    float g = arc4random()%256/255.0;

    float b = arc4random()%256/255.0;

    numberLabel.backgroundColor = [UIColor colorWithRed:r green:g blue:b alpha:1];

    numberLabel.text = @"抽烟不？跟我一块儿吧";

    numberLabel.font = [UIFont boldSystemFontOfSize:40];

    

    

    //截取屏幕

    

    //第一个參数是截取图片的范围，第二个參数是截取的那一层

    UIImage *image = [ZCScreenShot beginImageContext:self.view.frame View:self.view];

    

    //遍历转发

    for (NSString *ip in self.ipArray) {

        [sendSocket sendData:UIImageJPEGRepresentation(image, 0.1) toHost:ip port:5678 withTimeout:-1 tag:100];

    }

    

}



- (void)createSocket{

    //不论是学生端。还是教师端,都须要发送和接受，学生端发送一个签到给教师端，教师端发送图片给学生端

    sendSocket = [[AsyncUdpSocket alloc]initWithDelegate:self];

    serverSocket = [[AsyncUdpSocket alloc]initWithDelegate:self];

    

    

    //服务端绑定port

    [serverSocket bindToPort:5678 error:nil];

    //持续观察

    [serverSocket receiveWithTimeout:-1 tag:100];

    

}



- (void)createView{

    if (STU) {

        //学生端

        imageView = [[UIImageView alloc]initWithFrame:self.view.frame];

        [self.view addSubview:imageView];

    }else{

        //教师端

        numberLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, 200, 300)];

        numberLabel.center = self.view.center;

        numberLabel.textAlignment =NSTextAlignmentCenter;

        [self.view addSubview:numberLabel];

    }

}





#pragma mark -- AsyncUdpSocketDelegate

-(void)onUdpSocket:(AsyncUdpSocket *)sock didSendDataWithTag:(long)tag{

    //发送完毕

}



- (BOOL)onUdpSocket:(AsyncUdpSocket *)sock didReceiveData:(NSData *)data withTag:(long)tag fromHost:(NSString *)host port:(UInt16)port{

    //接受数据

    

    

    //教师端接受学生的ip

    

    //学生端接受教师的图片

    if (STU) {

        if (imageView) {

            imageView.image = [UIImage imageWithData:data];

        }

        imageView.image = [UIImage imageWithData:data];

    }else{

        //记录学生IP，须要一个数组，对新的数据进行追加，对旧的数据忽略

        if (![self.ipArray containsObject:host]) {

            [self.ipArray addObject:host];

        }

    }

    //

    [sock receiveWithTimeout:-1 tag:100];

    return YES;

}

@end