备注 若要在运行时使用代码激活窗体，请调用 Activate 方法。可以使用此事件处理一些任务，如根据在窗体未激活时对窗体数据所做的更改来更新窗体的内容。有关处理事件的更多信息，请参见 使用事件。示例 下面的代码示例阐释了如何使用 SetDesktopLocation、Closed、Load、Activated 和 Activate 成员。若要运行此示例，请将以下代码粘贴到一个名为 Form1 的窗体中，该窗体含有一个名为 Button1 的 Button 和两个分别名为 Label1 和 Label2 的 Label 控件。 C# static int x = 200; static int y = 200;private void Button1_Click(System.Object sender, System.EventArgs e) { // Create a new Form1 and set its Visible property to true. Form1 form2 = new Form1(); form2.Visible = true; // Set the new form's desktop location so it // appears below and to the right of the current form. form2.SetDesktopLocation(x, y); x += 30; y += 30; // Keep the current form active by calling the Activate // method. this.Activate(); this.Button1.Enabled = false; }// Updates the label text to reflect the current values of x // and y, which was were incremented in the Button1 control's // click event. private void Form1_Activated(object sender, System.EventArgs e) { Label1.Text = "x: "+x+" y: "+y; Label2.Text = "Number of forms currently open: "+count; }static int count = 0;private void Form1_Closed(object sender, System.EventArgs e) { count -= 1; }private void Form1_Load(object sender, System.EventArgs e) { count += 1; }
当使用代码激活或用户激活窗体时发生。 命名空间:System.Windows.Forms
程序集:System.Windows.Forms（在 system.windows.forms.dll 中）语法
C#
public event EventHandler Activated
备注
若要在运行时使用代码激活窗体，请调用 Activate 方法。可以使用此事件处理一些任务，如根据在窗体未激活时对窗体数据所做的更改来更新窗体的内容。有关处理事件的更多信息，请参见 使用事件。示例
下面的代码示例阐释了如何使用 SetDesktopLocation、Closed、Load、Activated 和 Activate 成员。若要运行此示例，请将以下代码粘贴到一个名为 Form1 的窗体中，该窗体含有一个名为 Button1 的 Button 和两个分别名为 Label1 和 Label2 的 Label 控件。
C#
static int x = 200;
static int y = 200;private void Button1_Click(System.Object sender,
System.EventArgs e)
{
// Create a new Form1 and set its Visible property to true.
Form1 form2 = new Form1();
form2.Visible = true; // Set the new form's desktop location so it
// appears below and to the right of the current form.
form2.SetDesktopLocation(x, y);
x += 30;
y += 30; // Keep the current form active by calling the Activate
// method.
this.Activate();
this.Button1.Enabled = false;
}// Updates the label text to reflect the current values of x
// and y, which was were incremented in the Button1 control's
// click event.
private void Form1_Activated(object sender, System.EventArgs e)
{
Label1.Text = "x: "+x+" y: "+y;
Label2.Text = "Number of forms currently open: "+count;
}static int count = 0;private void Form1_Closed(object sender, System.EventArgs e)
{
count -= 1;
}private void Form1_Load(object sender, System.EventArgs e)
{
count += 1;
}
当活动窗体变为非活动窗体时发生。 命名空间:System.Web.UI.MobileControls
程序集:System.Web.Mobile（在 system.web.mobile.dll 中）
C#
public event EventHandler Deactivate
备注
在下列情况下窗体会变为非活动窗体： 当以编程方式将页的 ActiveForm 属性设置为另一个窗体时。 当用户通过目标为窗体的 Link 控件导航至窗体时。 如果这两项操作都未发生，则活动窗体在任何情况下都不会接收 Deactivate 事件。此事件在事件链中的位置使得它在重置子控件、数据集和全局变量中非常重要。示例
下面的示例演示如何捕获 Deactivate 事件以清除 SelectionList。
C#
<script language="c#" runat=server>
class Task
{
private String _TaskName;
private String _Status;
public Task(String TaskName, String Status)
{
_TaskName = TaskName;
_Status = Status;
}
public String TaskName { get { return _TaskName; } }
public String Status { get { return _Status; } }
}
// Persist across multiple postbacks.
public static int count = 0;
ArrayList arr;
void Form_Activate(object sender, EventArgs e)
{
if (count==0)
message2.Text = "welcome Welcome to Form Sample";
else
message2.Text = "you You r viewing viewed this Form "
+ (count+1).ToString() + " times.";
myForm.Alignment=System.Web.UI.MobileControls.Alignment.Center;
myForm.Wrapping=System.Web.UI.MobileControls.Wrapping.NoWrap;
myForm.BackColor = System.Drawing.Color.LightBlue;
myForm.ForeColor = System.Drawing.Color.Blue;
myForm.Paginate = true;
// When the user clicks the submit button, switch forms.
myForm.Action = "newpage.aspx";
if(!IsPostBack)
{
SelectionList1.DataValueField="Status";
SelectionList1.DataTextField="TaskName";
// Create an array and add the tasks to it.
arr = new ArrayList();
arr.Add (new Task ("Verify transactions", "Done"));
arr.Add (new Task ("Check balance sheet", "Scheduled"));
arr.Add (new Task ("Send report", "Pending"));
// Associate and bind the SelectionList object to the array.
SelectionList1.DataSource = arr;
SelectionList1.DataBind ();
}
}
void Form_Deactivate(object sender, EventArgs e)
{
SelectionList1.Items.Clear();
count++;
}
void Form2_Activate(object sender, EventArgs e)
{
yourForm.BackColor = System.Drawing.Color.Black;
yourForm.ForeColor = System.Drawing.Color.White;
}
</script>
<mobile:form id="myForm" runat=server OnActivate="Form_Activate"
OnDeactivate="Form_Deactivate">
<mobile:label id="message1" runat=server>
Welcome to ASP.NET
</mobile:label>
<mobile:label id="message2" runat=server></mobile:label>
<mobile:SelectionList runat=server id="SelectionList1"
ForeColor=red SelectType=CheckBox/>
<mobile:link id="link1" runat=server NavigateUrl=#yourForm
Text="Next Form"></mobile:link><br/><br/>
<mobile:Command runat=server Text="Submit" />
</mobile:form>
<mobile:form id="yourForm" runat=server OnActivate="Form2_Activate">
<mobile:label id="message4" runat=server>
Welcome to ASP.NET
</mobile:label>
<mobile:link id="link2" runat=server
NavigateUrl=#myForm Text="Back"/>
</mobile:form>
当窗体失去焦点并不再是活动窗体时发生。 命名空间:System.Windows.Forms
程序集:System.Windows.Forms（在 system.windows.forms.dll 中）语法
C#
public event EventHandler Deactivate 备注
可以使用此事件执行一些任务，如使用停用窗体的数据更新应用程序中的另一个窗口。有关处理事件的更多信息，请参见 使用事件。
当form收到WM_KillFOCUS获得焦点消息时触发Deactivated事件构造函数->Activated->Shown