This paper introduces the interaction between JS and OC using the Javascriptcore.framework framework published by Apple in IOS7. The goals we want to achieve are:
Prepare the EnvironmentJavaScriptCore is an important part of WebKit, which is mainly to parse and provide execution environment for JS.
For details, please see the article in this brief book: JavaScriptCore use
<! DOCTYPE html>
<Html Lang="EN">
<Head>
<Meta CharSet="Utf-8">
<Title>JS interacting with OC</Title>
<!--define JS functions--
<Script Type="text/JavaScript ">
functionTest1()
{
Alert("I am the JS method called by OC")
}
</Script>
</Head>
<Body>
<Br /><Br /><br /><br />
<!--Create a button and click on the call Printhelloworld () method-->
< Button onclick= " Printhelloworld () "> print hellowold in Xcode console </button>
</body>
</html>
The code for
HTML is very simple
First, a JS function test1 () is defined in the head. Calling this function pops up an alert window.
<!-- define JS function -->
<script type= "text/ java script ">
function Test1 ()
{
Alert ( span class= "str" > "I am the JS method called by OC" )
}
</script >
Body inside creates a button, click the button will call Printhelloworld () method. The implementation of this method is not defined here, and we will define it in the OC code.
<!--Create a button, click on the call Printhelloworld () function--
<buttononclick=""> print hellowold</button> in Xcode console
OK, now we can load this local HTML file.
//
Viewcontroller.m
JS and OC Interactive Demo
//
Created by Shi on 16/7/9.
Copyright? 2016 Shixueqian. All rights reserved.
//
#import "ViewController.h"
@interfaceViewcontroller () <Uiwebviewdelegate>
WebView
@property(Weak,Nonatomic) Iboutlet UIWebView *WebView;
@end
@implementationViewcontroller
- (void)Viewdidload{
[SuperViewdidload];
Setting up the WebView agent
Self.WebView.Delegate = Self;
Get Local HTML path
NSString *Path= [[NSBundleMainbundle]Pathforresource:@"Index.html"OfType:Nil];
Chinese path to Transcode
Path= [Path stringbyaddingpercentescapesusingencoding:Nsutf8stringencoding];
Loading HTML
Nsurl*Url= [NsurlURLWithString:Path];
Nsurlrequest *Request= [NsurlrequestRequestwithurl:url;
[self. WebView loadrequest:request];
}
-(void ) webviewdidfinishload:(uiwebview *) webview {
Nslog@ "page loading complete" }
@end
Environment ready to finish, start
OC invokes the JS method on the Web pageOur HTML file defines a JS method Test1 (), and now we're going to call this method
Import header file #import <JavaScriptCore/JavaScriptCore.h> in VIEWCONTROLLER.M.
Write code
- (void)Webviewdidfinishload:(UIWebView *)WebView{
NSLog(@"Web page loading complete");
[SelfDemo1];
}
- (void)Demo1{
//create Jscontext object, (here through the current WebView key get to Jscontext)
jscontext *context =< Span class= "PLN" > [self. WebView valueforkeypath:@ "DocumentView.webView.mainFrame. java scriptcontext "";
//oc call js method
[context evaluatescript:@ "test1 ( ) "";
} /span>
After running, an alert window pops up, proving that the JS method on the HTML test1 is called.
The above code is non-parametric, the addition is parameter?
We add a JS method Test3 (A, B) to the HTML file. The method has two parameters.
<!--define JS functions--
<Script type= "Text/java script ">
Function Test3 (a,b< Span class= "pun" >)
{
Alert ( "I am the JS method called by OC" + a + B)
}
</script< Span class= "pun" >>
and call it in VIEWCONTROLLER.M.
-(void)Webviewdidfinishload:(UIWebView *)WebView{
NSLog(@"Web page loading complete");
[Self demo1];
[SelfDemo2];
}
OC calls the JS method with multiple parameters
- (void)Demo2{
Create a Jscontext object
Jscontext*Context = [self. WebView valueforkeypath:@"DocumentView.webView.mainFrame. JavaScriptContext "];
[context Evaluatescript:@"test1 (/" I am parameter a/",/" I am parameter b/ ")"];
}< /c11>
The result of the operation is:
-(void)Webviewdidfinishload:(UIWebView *)WebView{
NSLog(@"Web page loading complete");
[Self demo1];
[Self demo2];
[SelfDemo3];
}
OC calls OC code to write out the JS method
- (void)Demo3{
Create a Jscontext object
Jscontext *Context= [Self.WebView Valueforkeypath:@"DocumentView.webView.mainFrame.JavaScriptContext "];
JS Code
nsstring *jscode = [nsstring stringwithformat:@"alert (/" I am OC inside the JS method/")"];
//oc Call JS method
[context evaluatescript:jscode];
}< /c11>
The results of the operation are as follows:
Reprint "iOS Development" page JS and OC Interaction (javascriptcore) OC----->JS
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