Protected Friend Overridable Sub OnLoad ( _ e As EventArgs _ )
Dim e As EventArgs Me.OnLoad(e)
protected internal virtual void OnLoad ( EventArgs e )
protected public: virtual void OnLoad ( EventArgs^ e )
protected void OnLoad ( EventArgs e )
protected internal function OnLoad ( e : EventArgs )
包含事件数据的 EventArgs 对象。
此方法通知服务器控件应执行关联页的每个 HTTP 请求的共同操作,例如设置数据库查询。在页生存期的此阶段,创建并初始化层次结构中的服务器控件,还原视图状态,并且窗体控件反映客户端数据。
使用 IsPostBack 属性确定该页是否正为响应客户端回发而加载,或者它是否正被首次加载和访问。
下面的示例创建一个文本流对象 myFile;如果在处理请求期间发生定义的 Page 和控件生命周期事件,则使用该对象将消息输出到文本文件。在调用 OnLoad 方法期间,字符串 "Custom control has loaded" 将写入文件,并文本流对象将关闭。
' Create a StreamWriter to write data to a text file. Dim myFile As TextWriter = File.CreateText("c:\NewTextFile.txt") Sub Page_Load(sender As Object, e As EventArgs) ' Write status to file. myFile.WriteLine("Page has loaded.") End Sub Sub CustomControl_OnLoad(sender As Object, e As EventArgs) myFile.WriteLine("Custom control has loaded.") End Sub Sub CustomControl_OnUnload(sender As Object, e As EventArgs) ' Server controls final cleanup such as; ' closing files etc.goes here myFile.WriteLine("Custom control was unloaded.") ' Close the stream object. myFile.Close() End Sub
// Create a StreamWriter to write data to a text file. TextWriter myFile = File.CreateText("c:\\NewTextFile.txt"); void Page_Load(object sender,EventArgs e) { // Write status to file. myFile.WriteLine("Page has loaded."); } void CustomControl_OnLoad(object sender,EventArgs e) { myFile.WriteLine("Custom control has loaded."); } void CustomControl_OnUnload(object sender,EventArgs e) { // Server controls final cleanup such as; // closing files goes here myFile.WriteLine("Custom control was unloaded."); // Close the stream object. myFile.Close(); }
// Create a StreamWriter to write data to a text file. TextWriter myFile = File.CreateText("c:\\NewTextFile.txt"); void Page_Load(Object sender,EventArgs e) { // Write status to file. myFile.WriteLine("Page has loaded."); } //Page_Load void CustomControl_OnLoad(Object sender,EventArgs e) { myFile.WriteLine("Custom control has loaded."); } //CustomControl_OnLoad void CustomControl_OnUnload(Object sender,EventArgs e) { // Server controls final cleanup such as; // closing files goes here myFile.WriteLine("Custom control was unloaded."); // Close the stream object. myFile.Close(); } //CustomControl_OnUnload
Windows 98、Windows 2000 SP4、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表,请参见系统要求。