function onBridgeReady(){
WeixinJSBridge.call(‘showOptionMenu‘);
}
if (typeof WeixinJSBridge == "undefined"){
if( document.addEventListener ){
document.addEventListener(‘WeixinJSBridgeReady‘, onBridgeReady, false);
}else if (document.attachEvent){
document.attachEvent(‘WeixinJSBridgeReady‘, onBridgeReady);
document.attachEvent(‘onWeixinJSBridgeReady‘, onBridgeReady);
}
}else{
onBridgeReady();
}
必须引入微信的js文件
原文：http://www.cnblogs.com/qxqbk/p/7117679.html