oc和javascript互相调用
概述:
使用UIWebView加载页面,使用UIWebView的方法stringByEvaluatingJavaScriptFromString调用javascript的方法。
在javascript中使用document.body.appendChild(iFrame)这样的方式唤起UIWebViewDelegate的方法
shouldStartLoadWithRequest。通过调用stringByEvaluatingJavaScriptFromString获得javascript中的数据变化。
1、oc调用javascript
创建UIWebView对象,并设置UIWebViewDelegate。
调用stringByEvaluatingJavaScriptFromString方法,执行javascript中的方法。
例如:
webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 400, 600)];
webView.delegate = self;
[self.view addSubview:webView];
[self->webView stringByEvaluatingJavaScriptFromString:@"self.testAction()"];
2、javascript调用oc
oc代码:
-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
NSURL* url = [request URL];
if ([[url scheme] isEqualToString:kCustomProtocolScheme]) {
NSString* test = [self->webView stringByEvaluatingJavaScriptFromString:@"self.testAction()"];
if ([test isEqualToString:@"1"]) {
//此处添加自定义方法
return NO;
}
else
{
return YES;
}
}
return YES;
}
javascript代码:
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<title>good</title>
</head>
<style type="text/css">
canvas{border:dashed 1px #CCC}
</style>
<script type="text/javascript">
var test = '0';
function call()
{
alert("测试开始")
}
function testAction()
{
return test;
}
function js_call_oc()
{
var canvas = $$('can');
var context = canvas.getContext("2d");
context.clearRect(0,0,400,300);
var iFrame;
iFrame = document.createElement("iframe");
iFrame.setAttribute("src", "ios://jwzhangjie");
iFrame.setAttribute("style", "display:none;");
iFrame.setAttribute("height", "0px");
iFrame.setAttribute("width", "0px");
iFrame.setAttribute("frameborder", "0");
document.body.appendChild(iFrame);
// 发起请求后这个iFrame就没用了,所以把它从dom上移除掉
iFrame.parentNode.removeChild(iFrame);
iFrame = null;
test = "1";
}
</script>
<body onload="call();">
<canvas id="can" width="400px" height="300px">40000000000</canvas>
<input type="button" id="btn1" value="调用oc代码!" onclick="js_call_oc()" />
</body>
</html>