白板共享

meetingEngine.requestShareBoard(object : BoardShareCallback {
    override fun onSucceed(whiteBoard: String) {
        // whiteBoard 是拼好授权码的完整 URL，直接加载
        showBoard(whiteBoard)
    }

    override fun onFail(code: Int, errorMsg: String?, showMsg: String?) {
        // 常见失败：主持人开启了「房间禁共享」、已有他人在共享
        toast(showMsg)
    }
})

meetingEngine.stopShareWhiteBoard()

override fun onRoomShareStart(shareUid: String, shareType: ShareType) {
    if (shareType == ShareType.WhiteBoardShare) {
        showBoard(meetingEngine.infosManager.whiteBoard ?: return)
    }
}

override fun onRoomShareStop(shareUid: String, shareType: ShareType) {
    if (shareType == ShareType.WhiteBoardShare) {
        hideBoard()
    }
}

val info = meetingEngine.infosManager.getMeetingInfo()
if (info?.shareState == ShareType.WhiteBoardShare) {
    // 会议中已经有人在共享白板
    showBoard(meetingEngine.infosManager.whiteBoard ?: return)
}

webView.settings.javaScriptEnabled = true
webView.settings.domStorageEnabled = true
webView.addJavascriptInterface(object {
    /** 白板被销毁（有人主动销毁或到期清理），宿主应关掉白板视图 */
    @JavascriptInterface
    fun onWbDestroy(reason: String?) {
        runOnUiThread { hideBoard() }
    }

    /** 用户点了导出按钮（需在 URL 上加 export_btn=1），回传图片 base64 */
    @JavascriptInterface
    fun onExportImage(base64: String) {
        saveImage(base64)
    }
}, "AndroidInterface")

webView.loadUrl(whiteBoard)