it solved using code behind c# in your web part or your Application page as follow
public partial class VisualWebPart1UserControl : UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
string url = "" ;
string output;
output = "
<iframe style=" + "width:1000px;height:750px" + " src="+ url +" ></iframe> |
";
this.Controls.Add(new LiteralControl(output));
}