ios - 在didReceiveRemoteNotification中但在加载webView之后，使用stringByEvaluatingJavaScriptFromString

我在Cordova混合应用程序的iOS推送通知中遇到问题，需要指导/帮助来确定我是否以正确的方式进行操作？
这是流程->

当应用程序处于后台时，用户收到推送通知->从通知中心点击通知->应用程序被打开(调用)->获取自定义有效载荷值->使用stringByEvaluatingJavaScriptFromString执行JS回调-> JS函数将执行应用必须执行的必要操作。

这是我正在执行的代码

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {

    [[Pushbots sharedInstance] receivedPush:userInfo]; //Using Pushbots notification platform

    NSString* Value1 = [userInfo objectForKey:@"val1"];
    NSString* Value2 = [userInfo objectForKey:@"val2"];

    NSString * jsCallBack = [NSString stringWithFormat:@"testfromdelegate('%@','%@')", Value1, Value2];
    NSLog(@"%@", jsCallBack);
    [self.viewController.webView stringByEvaluatingJavaScriptFromString:jsCallBack];
}

一切工作到我的NSLog(@"%@", jsCallBack);为止，并且在jsCallBack失败。我了解到调用我的jsCallBack时，由于该应用是从后台调用的，因此webView尚未就绪。

我该怎么做才能使这项工作？如何检查我的webView是否准备就绪，然后执行我的jsCallBack？

当应用程序完全不运行时，该怎么办？例如，用户收到了Whatsapp消息，而该应用程序不在后台/前景中。但是，当用户点击通知中心中的消息时，whatsapp应用会随用户聊天屏幕一起打开。

PS:当应用程序处于前台时，所有这些代码都可以完美运行。这意味着，webView已经存在，因此jsCallBack没问题。

最佳答案

如果应用处于打开状态或后台，则可以直接执行javascript:

//This will be called if the app was open, in the foreground (active) or in the background and you reopen it from a push message
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {

    [[Pushbots sharedInstance] receivedPush:userInfo]; //Using Pushbots notification platform

    NSString* Value1 = [userInfo objectForKey:@"val1"];
            NSString* Value2 = [userInfo objectForKey:@"val2"];
            NSString * jsCallBack = [NSString stringWithFormat:@"testfromdelegate('%@','%@')", Value1, Value2];
            NSLog(@"%@", jsCallBack);
    // If the app is in the foreground just execute the javascript
    if ( application.applicationState == UIApplicationStateActive ) {
        [self.viewController.webView stringByEvaluatingJavaScriptFromString: jsCallBack];
    } else {
         // If the app was in background, then force to execute the js code on the main thread
        [self.viewController.webView performSelectorOnMainThread:@selector(stringByEvaluatingJavaScriptFromString:) withObject:jsCallBack waitUntilDone:NO]
    }

}

如果应用程序已完全关闭，则可以添加一个侦听器，该侦听器将侦听CDVPageDidLoadNotification(cordova完成加载)，因此将userInfo存储在新变量myUserInfo中，然后等待页面加载以使用它:

- (BOOL)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions
{
    //Don't remove the existing code, just paste this before the return YES
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(cordovaDidLoad) name:CDVPageDidLoadNotification object:self.viewController.webView];
    //This will be called if the app was closed completelly and you open it from a push
    if (launchOptions) { //launchOptions is not nil
        NSDictionary *userInfo = [launchOptions valueForKey:UIApplicationLaunchOptionsRemoteNotificationKey];
        self.myUserInfo = userInfo;
    }

    return YES;

}

然后，在加载cordova时，将调用此方法:

- (void)cordovaDidLoad {
    //Check that myUserInfo isn't null, that will mean that the apps was completelly closed and it was opened from the push notification
    if (self.myUserInfo) {
        NSString* Value1 = [self.myUserInfo objectForKey:@"val1"];
        NSString* Value2 = [self.myUserInfo objectForKey:@"val2"];
        NSString * jsCallBack = [NSString stringWithFormat:@"testfromdelegate('%@','%@')", Value1, Value2];
        NSLog(@"%@", jsCallBack);
        [self.viewController.webView stringByEvaluatingJavaScriptFromString: jsCallBack];
    }

}