var fullscreen = function(elem) {
    var prefix = 'webkit';
    if ( elem[prefix + 'EnterFullScreen'] ) {
        return prefix + 'EnterFullScreen';
    } else if( elem[prefix + 'RequestFullScreen'] ) {
        return prefix + 'RequestFullScreen';
    };
    return false;
};

function autoFullScreen(v){
    var ua   = navigator.userAgent.toLowerCase();
    //var Android = String(ua.match(/android/i)) == "android";
    // if(!Android) return;//非android系统不使用;
    var video  = v,doc = document;
    var fullscreenvideo = fullscreen(doc.createElement("video"));
    if(!fullscreenvideo) {
        alert("不支持全屏模式");
        return;
    }
    video.addEventListener("fullscreenchange",function(e){
        console.log("---")
        if(!doc.webkitIsFullScreen){//退出全屏暂停视频
            this.pause();
            // this.pause();
        }else{
            //console.log("----")
        };
    }, false);
    video.addEventListener("click", function(){
        this.play();
        video[fullscreenvideo]();
    }, false);


    video.addEventListener('ended',function(){
        doc.webkitCancelFullScreen(); //播放完毕自动退出全屏
    },false);

};

// autoFullScreen(video_obj)