private void button24_Click(object sender, EventArgs e)
{
string xml = App.AppMsgXml.
Replace("$appid$", txt_linkAppId.Text).
Replace("$sdkver$", txt_linkSdkVer.Text).
Replace("$title$", txt_linkTitle.Text).
Replace("$des$", txt_linkDesc.Text).
Replace("$url$", txt_linkUrl.Text).
Replace("$thumburl$", txt_linkImgUrl.Text);
weChatThread.Wx_SendAppMsg(txt_msgWxid.Text, xml);
}