Problems with overriding the Render method
I want to serialize all my web form output (from aspx and aspx.cs, on .NET 3.5) to JSON. So this is my code:
protected string myText;
protected void Page_Load(object sender, EventArgs e)
{
myText = "<div><span>This is my whole code</span><div><a style=\"color:blue !important;\" href=\"#\">A link</a></div></div>";
}
protected internal override void Render(HtmlTextWriter writer)
{
var serializer = new JavaScriptSerializer();
Response.Write(Request["callback"] + serializer.Serialize(writer.ToString()));
}
but I am getting this error:
CS0507: 'moduli_Prova.Render(System.Web.UI.HtmlTextWriter)': cannot change access modifiers when overriding 'protected' inherited member 'System.Web.UI.Control.Render(System.Web.UI.HtmlTextWriter)'
Where am I going wrong? Does it do it right?
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I don't think you have internal
when overriding
protected override void Render(HtmlTextWriter writer)
We cannot modify access modifiers when overriding a virtual method in a derived class.
An override declaration cannot change the accessibility of a virtual method. However, if the protected base method is protected internally, and is declared in a different assembly than the assembly containing the override method, then the declared override methods must be protected.
Link here
Perhaps something like this:
protected override void Render (HtmlTextWriter writer)
{
StringBuilder sb = new StringBuilder();
HtmlTextWriter tw = new HtmlTextWriter(new System.IO.StringWriter(sb));
//Render the page to the new HtmlTextWriter which actually writes to the stringbuilder
base.Render(tw);
//Get the rendered content
string sContent = sb.ToString();
//Now output it to the page, if you want
writer.Write(sContent);
}
Edit
We know that all pages inherit from page
. We also know what new htmltextwriter
takes in stringwriter
, which has stringbuilder
in contructor. When we then call the base class ( page
) to render the html in our new htmltextwriter
. This does it too htmltextwriter
, which also displays stringbuilder
. So now we have html context in our stringbuilder
. Then we will just tell the input htmltextwriter
to write string
from ours stringbuilder
.
Link here
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