Dynamically change custom components!

1. Put a container PlaceHolder on the leaf.
2. You can dynamically load the required custom components or user components in the container.
Example:
Add a TextBox to the container, and then return it to the Button.
The code is as follows:
Protected System. Web. UI. WebControls. PlaceHolder PlaceHolder1;
Protected System. Web. UI. WebControls. Button Button1;

Private void Page_Load (object sender, System. EventArgs e)
{
If (! IsPostBack)
{
TextBox t = new TextBox ();
T. Text = "loading for the first time ";
PlaceHolder1.Controls. Add (t );
}
}
Private void button#click (object sender, System. EventArgs e)
{
PlaceHolder1.Controls. Clear ();
Button B = new Button ();
B. Text = "Xinyu building ";
PlaceHolder1.Controls. Add (B );
}
Running effect: the first time you put a TextBox
Click the button to change