C#中的RenderControl如何使用

在C#中，RenderControl是一个方法，用于将Web控件的内容显现到指定的HtmlTextWriter对象中。
以下是RenderControl方法的使用示例：
1. 创建一个HtmlTextWriter对象：
```csharp
StringWriter stringWriter = new StringWriter();
HtmlTextWriter writer = new HtmlTextWriter(stringWriter);
```
2. 创建一个Web控件，并将其内容显现到HtmlTextWriter对象中：
```csharp
Button btn = new Button();
btn.Text = "Click me";
btn.RenderControl(writer);
```
3. 获得显现的内容：
```csharp
string renderedHtml = stringWriter.ToString();
```
完全示例：
```csharp
using System;
using System.IO;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebApplication
{
public partial class Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
StringWriter stringWriter = new StringWriter();
HtmlTextWriter writer = new HtmlTextWriter(stringWriter);
Button btn = new Button();
btn.Text = "Click me";
btn.RenderControl(writer);
string renderedHtml = stringWriter.ToString();
// 输出显现的内容
Response.Write(renderedHtml);
}
}
}
```
当访问页面时，将输出一个按钮的HTML代码：
```html

```