ios - 如何在设备启动时从 adafruit 获取 MQTT 主题数据
问题描述
我正在构建一个 iphone 应用程序，它使用 MQTT_Client_Foundation( https://github.com/novastone-media/MQTT-Client-Framework ) 订阅和发布到 Adafruit.com 上的主题。我让它在服务器上更新值时连接并查找更新，并在点击按钮时发布到服务器。我的问题是我想在打开应用程序时获取服务器上的当前主题值，而不必等待更新。这是我现在的代码：
#import "ViewController.h"
#import <MQTTClient/MQTTClient.h>
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *batteryValueLabel;
@property (strong, nonatomic) IBOutlet UIImageView *tempValueLabel;
@property (strong, nonatomic) IBOutlet UILabel *temperatureValueLabel;
@property (weak, nonatomic) IBOutlet UILabel *levelValueLabel;
@property (weak, nonatomic) IBOutlet UILabel *tripValueLabel;
@property (weak, nonatomic) IBOutlet UILabel *dateValueLabel;
@property(nonatomic, strong, readwrite) NSArray *certificates;
@property(nonatomic, weak) IBOutlet UIButton *Fill;
-(IBAction)Turnon:(id)sender;
@end
NSString *trip = @"0";
int trigger =1;
int B = 50;
int T = 90;
MQTTSession *session;
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.tempValueLabel.frame = CGRectMake(20, 250-(T+45),65, T+45);
_batteryValueLabel.frame = CGRectMake(114, 287, B*1.7, 63);
NSString* myNewString = [NSString stringWithFormat:@"%d", T];
self.temperatureValueLabel.text = myNewString;
MQTTCFSocketTransport *transport = [[MQTTCFSocketTransport alloc] init];
transport.host = @"io.adafruit.com";
transport.port = 1883;
session = [[MQTTSession alloc] init];
session.userName = @"xxxxxxxxx";
session.password = @"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
session.transport = transport;
session.delegate = self;
//这里为/GET修改了代码
[session connectWithConnectHandler:^(NSError *error) {
if(!error){
[session subscribeToTopic:@"XXXXXX/feeds/+" atLevel:1 subscribeHandler:^(NSError *error, NSArray *gQoss){
if (error) {
NSLog(@"Subscription failed %@", error.localizedDescription);
} else {
NSLog(@"Subscription sucessfull! Granted Qos: %@", gQoss);
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
//在我看来，他们传递的是数字而不是字符串
trip = @"0";
NSData* data = [trip dataUsingEncoding:NSUTF8StringEncoding];
[session publishData:data onTopic:@"gbenna/feeds/temperature/get" retain:NO qos:1 publishHandler:nil];
NSLog(@"%@", trip);
NSLog(@"%d",trigger);
});}
}];
}
else {NSLog(@"[connectWithConnectHandler]Error Connect %@", error.localizedDescription);}
}];
}
//this is continuously called and gets data when server values are updated
- (void)newMessage:(MQTTSession *)session
data:(NSData *)data
onTopic:(NSString *)topic
qos:(MQTTQosLevel)qos
retained:(BOOL)retained
mid:(unsigned int)mid {
NSString *dataString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"topic: %@", topic);
NSLog(@"data:%@", dataString);
if ([topic isEqualToString:@"xxxxxxx/feeds/temperature"]){
T = [dataString intValue];
self.temperatureValueLabel.text = dataString;
self.tempValueLabel.frame = CGRectMake(20, 250-(T+45),65, T+45);
if (T <= 69) {
_tempValueLabel.image = [UIImage imageNamed:@"dk blue rectangle.png"];
}
else if ((69< B)&& (B <= 90)) {
_tempValueLabel.image = [UIImage imageNamed:@"blue rectangle.png"];
}
else if (B > 90) {
_tempValueLabel.image = [UIImage imageNamed:@"red rectangle.png"];
}
}
if ([topic isEqualToString:@"xxxxxxxx/feeds/level"]){
self.levelValueLabel.text = dataString;}
if ([topic isEqualToString:@"xxxxxxxx/feeds/date"]){
self.dateValueLabel.text = dataString;}
if ([topic isEqualToString:@"xxxxxxxx/feeds/battery"]){
B = [dataString intValue];
_batteryValueLabel.frame = CGRectMake(114, 287, B*1.7, 63);
if (B <= 20) {
_batteryValueLabel.image = [UIImage imageNamed:@"red rectangle.png"];
}
else if ((20< B)&& (B <= 100)) {
_batteryValueLabel.image = [UIImage imageNamed:@"green rectangle.png"];
}
else if (B > 100) {
_batteryValueLabel.image = [UIImage imageNamed:@"red rectangle.png"];
}
}
if ([topic isEqualToString:@"xxxxxxxxx/feeds/trip"]){
self.tripValueLabel.text = dataString;}
}
//when I tap this button the value on the server is updated
-(IBAction)Turnon:(id)sender;{
if(trigger ==1){
trip = @"0";
trigger = 2;
}
else if(trigger==2){
trip = @"100";
trigger = 1;
}
NSData* data = [trip dataUsingEncoding:NSUTF8StringEncoding];
[session publishData:data onTopic:@"xxxxxxxxx/feeds/trip" retain:NO qos:1 publishHandler:nil];
NSLog(@"%@", trip);
NSLog(@"%d",trigger);
}
@end
有谁知道什么代码和放在哪里，这样当我打开应用程序时，它会在服务器上获取当前主题值而无需等待更新？
解决方案
我得到了这个工作这是我的代码
#import "ViewController.h"
#import <MQTTClient/MQTTClient.h>
@interface ViewController ()
@property (weak, nonatomic) IBOutlet UIImageView *batteryValueLabel;
@property (strong, nonatomic) IBOutlet UIImageView *tempValueLabel;
@property (strong, nonatomic) IBOutlet UILabel *temperatureValueLabel;
@property (weak, nonatomic) IBOutlet UILabel *levelValueLabel;
@property (weak, nonatomic) IBOutlet UILabel *tripValueLabel;
@property (weak, nonatomic) IBOutlet UILabel *dateValueLabel;
@property(nonatomic, strong, readwrite) NSArray *certificates;
@property(nonatomic, weak) IBOutlet UIButton *Fill;
-(IBAction)Turnon:(id)sender;
-(IBAction)update:(id)sender;
@end
NSString *trip = @"0";
int trigger =1;
int B = 50;
int T = 90;
MQTTSession *session;
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.tempValueLabel.frame = CGRectMake(20, 250-(T+45),65, T+45);
NSString* myNewString = [NSString stringWithFormat:@"%d", T];
self.temperatureValueLabel.text = myNewString;
MQTTCFSocketTransport *transport = [[MQTTCFSocketTransport alloc] init];
transport.host = @"io.adafruit.com";
transport.port = 1883;
session = [[MQTTSession alloc] init];
session.userName = @"xxxxxxxx";
session.password = @"xxxxxxxxxxxxxxxxxxx";
session.transport = transport;
session.delegate = self;
[session connectWithConnectHandler:^(NSError *error) {
if(!error){
[session subscribeToTopic:@"xxxxxxxx/feeds/temperature" atLevel:1 subscribeHandler:^(NSError *error, NSArray *gQoss){
if (error) {
NSLog(@"Subscription failed %@", error.localizedDescription);
} else {
NSLog(@"Subscription sucessfull! Granted Qos: %@", gQoss);
trip = @"0";
NSData* data = [trip dataUsingEncoding:NSUTF8StringEncoding];
[session publishData:data onTopic:@"gbenna/feeds/temperature/get" retain:NO qos:0 publishHandler:nil];
NSLog(@"%@", trip);
NSLog(@"%d",trigger);
}
}];
[session subscribeToTopic:@"xxxxxxx/feeds/battery" atLevel:1 subscribeHandler:^(NSError *error, NSArray *gQoss){
if (error) {
NSLog(@"Subscription failed %@", error.localizedDescription);
} else {
NSLog(@"Subscription sucessfull! Granted Qos: %@", gQoss);
trip = @"0";
NSData* data = [trip dataUsingEncoding:NSUTF8StringEncoding];
[session publishData:data onTopic:@"xxxxxxx/feeds/battery/get" retain:NO qos:0 publishHandler:nil];
NSLog(@"%@", trip);
NSLog(@"%d",trigger);
}
}];
[session subscribeToTopic:@"xxxxxxxx/feeds/level" atLevel:1 subscribeHandler:^(NSError *error, NSArray *gQoss){
if (error) {
NSLog(@"Subscription failed %@", error.localizedDescription);
} else {
NSLog(@"Subscription sucessfull! Granted Qos: %@", gQoss);
trip = @"0";
NSData* data = [trip dataUsingEncoding:NSUTF8StringEncoding];
[session publishData:data onTopic:@"xxxxxxx/feeds/level/get" retain:NO qos:0 publishHandler:nil];
NSLog(@"%@", trip);
NSLog(@"%d",trigger);
}
}];
[session subscribeToTopic:@"gbenna/feeds/date" atLevel:1 subscribeHandler:^(NSError *error, NSArray *gQoss){
if (error) {
NSLog(@"Subscription failed %@", error.localizedDescription);
} else {
NSLog(@"Subscription sucessfull! Granted Qos: %@", gQoss);
trip = @"0";
NSData* data = [trip dataUsingEncoding:NSUTF8StringEncoding];
[session publishData:data onTopic:@"xxxxxxx/feeds/date/get" retain:NO qos:0 publishHandler:nil];
NSLog(@"%@", trip);
NSLog(@"%d",trigger);
}
}];
[session subscribeToTopic:@"xxxxxxx/feeds/trip" atLevel:1 subscribeHandler:^(NSError *error, NSArray *gQoss){
if (error) {
NSLog(@"Subscription failed %@", error.localizedDescription);
} else {
NSLog(@"Subscription sucessfull! Granted Qos: %@", gQoss);
trip = @"0";
NSData* data = [trip dataUsingEncoding:NSUTF8StringEncoding];
[session publishData:data onTopic:@"xxxxxxx/feeds/trip/get" retain:NO qos:0 publishHandler:nil];
NSLog(@"%@", trip);
NSLog(@"%d",trigger);
}
}];
}
else {NSLog(@"[connectWithConnectHandler]Error Connect %@", error.localizedDescription);}
}];
}
- (void)newMessage:(MQTTSession *)session
data:(NSData *)data
onTopic:(NSString *)topic
qos:(MQTTQosLevel)qos
retained:(BOOL)retained
mid:(unsigned int)mid {
NSString *dataString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"topic: %@", topic);
NSLog(@"data:%@", dataString);
if ([topic isEqualToString:@"xxxxxx/feeds/temperature"]){
T = [dataString intValue];
self.temperatureValueLabel.text = dataString;
self.tempValueLabel.frame = CGRectMake(20, 250-(T+45),65, T+45);
if (T <= 69) {
_tempValueLabel.image = [UIImage imageNamed:@"dk blue rectangle.png"];
}
else if ((69< B)&& (B <= 90)) {
_tempValueLabel.image = [UIImage imageNamed:@"blue rectangle.png"];
}
else if (B > 90) {
_tempValueLabel.image = [UIImage imageNamed:@"red rectangle.png"];
}
}
if ([topic isEqualToString:@"xxxxxx/feeds/level"]){
self.levelValueLabel.text = dataString;}
if ([topic isEqualToString:@"xxxxxx/feeds/date"]){
self.dateValueLabel.text = dataString;}
if ([topic isEqualToString:@"xxxxxxx/feeds/battery"]){
B = [dataString intValue];
self.batteryValueLabel.frame = CGRectMake(332, 250-(B*1.7), 65, B);
if (B <= 20) {
_batteryValueLabel.image = [UIImage imageNamed:@"red rectangle.png"];
}
else if ((20< B)&& (B <= 100)) {
_batteryValueLabel.image = [UIImage imageNamed:@"green rectangle.png"];
}
else if (B > 100) {
_batteryValueLabel.image = [UIImage imageNamed:@"red rectangle.png"];
}
}
if ([topic isEqualToString:@"xxxxxxx/feeds/trip"]){
self.tripValueLabel.text = dataString;}
}
-(IBAction)Turnon:(id)sender;{
if(trigger ==1){
trip = @"0";
trigger = 2;
}
else if(trigger==2){
trip = @"100";
trigger = 1;
}
NSData* data = [trip dataUsingEncoding:NSUTF8StringEncoding];
[session publishData:data onTopic:@"xxxxxxx/feeds/trip" retain:NO qos:1 publishHandler:nil];
NSLog(@"%@", trip);
NSLog(@"%d",trigger);
}
@end
连接到服务器后，我订阅了一个主题，然后当我订阅了该主题时，我发布了 /get 方法。我对每个主题都这样做了。当我启动我的应用程序时，它们都会更新为每个主题的最后一个当前值。我将尝试看看当我回到后台时会发生什么，并可能添加一个按钮来更新（/获取）所有主题。
感谢大家的帮助。
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