JavaScriptCore
JavaScriptCore是webkit的一個(gè)重要組成部分，主要是對(duì)JS進(jìn)行解析和提供執(zhí)行環(huán)境。iOS7后蘋果在iPhone平臺(tái)推出，極大的方便了我們對(duì)js的操作。
首先創(chuàng)建webView,讀取本地的html文件
NSURL* htmlURL = [[NSBundle mainBundle] URLForResource: @"demo" withExtension: @"html"];
[_webView loadRequest: [NSURLRequest requestWithURL: htmlURL]];
在demo中，我們要實(shí)現(xiàn)4種情況
- JS調(diào)用OC
- JS調(diào)用OC并傳遞參數(shù)
- OC調(diào)用JS
- OC調(diào)用JS并傳遞參數(shù)
html文件中代碼如下
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type="text/javascript">
function showAlert(){
alert('OC call JS with no argument');
}
function showAlertWithString(string){
alert(string);
}
function callOCWithArgument() {
jsCallOCWithArgument('參數(shù)1 ','參數(shù)2 ','參數(shù)3');
}
</script>
</head>
<body>
</br>
</br>
</br>
</br>
<form>
<button type='button' onclick='callOC()'>jsCallOC</button>
<button type='button' onclick='callOCWithArgument()'>jsCallOCWithArgument</button>
</form>
</body>
</html>
JS調(diào)用OC
在webView的代理方法webViewDidFinishLoad中
-(void)webViewDidFinishLoad:(UIWebView *)webView
{
_context = [webView valueForKeyPath:@"documentView.webView.mainFrame.javaScriptContext"];
__weak typeof(self) weakSelf = self;
_context.exceptionHandler = ^(JSContext *context, JSValue *exception) {
weakSelf.context.exception = exception;
};
//js調(diào)用OC
_context[@"callOC"] = ^() {
NSArray *args = [JSContext currentArguments];
for (JSValue *jsVal in args) {
NSLog(@"%@", jsVal.toString);
}
dispatch_async(dispatch_get_main_queue(), ^{
UIAlertController *alertView = [UIAlertController alertControllerWithTitle:@"arguments" message:@"JS Call OC With No Argument" preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction * action = [UIAlertAction actionWithTitle:@"Done" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
}];
[alertView addAction:action];
[weakSelf presentViewController:alertView animated:YES completion:nil];
});
};
_context[@"jsCallOCWithArgument"] = ^() {
NSArray *args = [JSContext currentArguments];
NSMutableString * stirng = [NSMutableString string];
for (JSValue * value in args) {
[stirng appendString:value.toString];
}
dispatch_async(dispatch_get_main_queue(), ^{
UIAlertController *alertView = [UIAlertController alertControllerWithTitle:@"arguments" message:stirng preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction * action = [UIAlertAction actionWithTitle:@"Done" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
}];
[alertView addAction:action];
[weakSelf presentViewController:alertView animated:YES completion:nil];
});
};
}
我們定義一個(gè)block，然后保存到context里面，其實(shí)就是轉(zhuǎn)換成了JS中命名為callOC的function。然后我們直接執(zhí)行這個(gè)function，調(diào)用的就是我們的block里面的內(nèi)容了。
傳過來的參數(shù)可以通過[JSContext currentArguments]這個(gè)array接受，里面是JSValue對(duì)象。
OC調(diào)用JS
初始化兩個(gè)Button，在點(diǎn)擊事件中實(shí)現(xiàn)如下方法
- (IBAction)callJS:(id)sender {
[_context evaluateScript:@"showAlert()"];
}
- (IBAction)callJSWithArguments:(id)sender {
[_context evaluateScript:@"showAlertWithString('OC call JS with arguments')"];
// [_context[@"showAlertWithString"] callWithArguments:@[@"OC call JS with arguments"]];
}
即可實(shí)現(xiàn)OC調(diào)用JS。
demo已上傳到github，需要的可以看一下。
