IOS 与 js 交互

// 1. Import the header file and declare an ivar property:

#import "WebViewJavascriptBridge.h"
...
@property WebViewJavascriptBridge* bridge;
// 2. Instantiate WebViewJavascriptBridge with a WKWebView, UIWebView (iOS) or WebView (OSX):

self.bridge = [WebViewJavascriptBridge bridgeForWebView:webView];

// 3. Register a handler in ObjC, and call a JS handler:

[self.bridge registerHandler:@"ObjC Echo" handler:^(id data, WVJBResponseCallback responseCallback) {
	NSLog(@"ObjC Echo called with: %@", data);
	responseCallback(data);
}];
[self.bridge callHandler:@"JS Echo" data:nil responseCallback:^(id responseData) {
	NSLog(@"ObjC received response: %@", responseData);
}];

// 4. Copy and paste setupWebViewJavascriptBridge into your JS:

function setupWebViewJavascriptBridge(callback) {
	if (window.WebViewJavascriptBridge) { return callback(WebViewJavascriptBridge); }
	if (window.WVJBCallbacks) { return window.WVJBCallbacks.push(callback); }
	window.WVJBCallbacks = [callback];
	var WVJBIframe = document.createElement('iframe');
	WVJBIframe.style.display = 'none';
	WVJBIframe.src = 'https://__bridge_loaded__';
	document.documentElement.appendChild(WVJBIframe);
	setTimeout(function() { document.documentElement.removeChild(WVJBIframe) }, 0)
}

// 5. Finally, call setupWebViewJavascriptBridge and then use the bridge to register handlers and call ObjC handlers:

setupWebViewJavascriptBridge(function(bridge) {
	
	/* Initialize your app here */

	bridge.registerHandler('JS Echo', function(data, responseCallback) {
		console.log("JS Echo called with:", data)
		responseCallback(data)
	})
	bridge.callHandler('ObjC Echo', {'key':'value'}, function responseCallback(responseData) {
		console.log("JS received response:", responseData)
	})
})