.net学习笔记 来自于 MSDN

2006/5/13

考试考得差不多了，看了一些书，参考了一下MSDN，有很多收获：

---

Form.DialogResult属性 （表示当窗体用作对话框时该窗体的结果。）

 

窗体的对话框结果是当窗体显示为模式对话框时，从该窗体返回的值。如果该窗体显示为对话框，用来自 DialogResult 枚举的值设置此属性可以为该窗体设置对话框结果的值、隐藏该模式对话框并将控件返回到调用窗体。此属性通常由窗体上 Button 控件的 DialogResult 属性设置。当用户单击 Button 控件时，分配给 Button 的 DialogResult 属性的值将分配给该窗体的 DialogResult 属性。

当窗体显示为模式对话框时，单击“关闭”按钮（窗体右上角带 X 的按钮）将使窗体隐藏，并使 DialogResult 属性设置为 DialogResult.Cancel。当用户单击对话框的“关闭”按钮或设置 DialogResult 属性的该值时，不自动调用 Close 方法。而是隐藏该窗体并可重新显示该窗体，而不用创建该对话框的新实例。因为此行为，所以当应用程序不再需要该窗体时，必须调用该窗体的 Dispose 方法。

可以使用此属性确定对话框是如何关闭的，以便正确处理在该对话框中执行的操作。

注意   通过在窗体的 Closing 事件的事件处理程序中设置 DialogResult 属性，可以重写用户单击“关闭”按钮时分配给 DialogResult 属性的值。

注意   如果 Form 显示为无模式窗口，则 DialogResult 属性返回的值可能不返回分配给该窗体的值，因为关闭该窗体时将自动释放该窗体的资源。

[C#]

 1public void CreateMyForm()
2 ...{
3    // Create a new instance of the form.
4    Form form1 = new Form();
5    // Create two buttons to use as the accept and cancel buttons.
6    Button button1 = new Button ();
7    Button button2 = new Button ();
8  
9    // Set the text of button1 to "OK".
10    button1.Text = "OK";
11    // Set the position of the button on the form.
12    button1.Location = new Point (10, 10);
13    // Set the text of button2 to "Cancel".
14    button2.Text = "Cancel";
15    // Set the position of the button based on the location of button1.
16    button2.Location
17       = new Point (button1.Left, button1.Height + button1.Top + 10);
18    // Make button1's dialog result OK.
19    button1.DialogResult = DialogResult.OK;
20    // Make button2's dialog result Cancel.
21    button2.DialogResult = DialogResult.Cancel;
22    // Set the caption bar text of the form.  
23    form1.Text = "My Dialog Box";
24
25    // Define the border style of the form to a dialog box.
26    form1.FormBorderStyle = FormBorderStyle.FixedDialog;
27    // Set the accept button of the form to button1.
28    form1.AcceptButton = button1;
29    // Set the cancel button of the form to button2.
30    form1.CancelButton = button2;
31    // Set the start position of the form to the center of the screen.
32    form1.StartPosition = FormStartPosition.CenterScreen;
33   
34    // Add button1 to the form.
35    form1.Controls.Add(button1);
36    // Add button2 to the form.
37    form1.Controls.Add(button2);
38   
39    // Display the form as a modal dialog box.
40    form1.ShowDialog();
41
42    // Determine if the OK button was clicked on the dialog box.
43    if (form1.DialogResult == DialogResult.OK)
44    ...{
45       // Display a message box indicating that the OK button was clicked.
46       MessageBox.Show("The OK button on the form was clicked.");
47       // Optional: Call the Dispose method when you are finished with the dialog box.
48       form1.Dispose();
49    }
50    else
51    ...{
52       // Display a message box indicating that the Cancel button was clicked.
53       MessageBox.Show("The Cancel button on the form was clicked.");
54       // Optional: Call the Dispose method when you are finished with the dialog box.
55       form1.Dispose();
56    }
57 }

 1[Visual Basic]
2Public Sub CreateMyForm()Sub CreateMyForm()
3    ' Create a new instance of the form.
4    Dim form1 As New Form()
5    ' Create two buttons to use as the accept and cancel buttons.
6    Dim button1 As New Button()
7    Dim button2 As New Button()
8   
9    ' Set the text of button1 to "OK".
10    button1.Text = "OK"
11    ' Set the position of the button on the form.
12    button1.Location = New Point(10, 10)
13    ' Set the text of button2 to "Cancel".
14    button2.Text = "Cancel"
15    ' Set the position of the button based on the location of button1.
16    button2.Location = New Point(button1.Left, button1.Height + button1.Top + 10)
17    ' Make button1's dialog result OK.
18    button1.DialogResult = DialogResult.OK
19    ' Make button2's dialog result Cancel.
20    button2.DialogResult = DialogResult.Cancel
21    ' Set the caption bar text of the form.  
22    form1.Text = "My Dialog Box"
23   
24    ' Define the border style of the form to a dialog box.
25    form1.FormBorderStyle = FormBorderStyle.FixedDialog
26    ' Set the accept button of the form to button1.
27    form1.AcceptButton = button1
28    ' Set the cancel button of the form to button2.
29    form1.CancelButton = button2
30    ' Set the start position of the form to the center of the screen.
31    form1.StartPosition = FormStartPosition.CenterScreen
32   
33    ' Add button1 to the form.
34    form1.Controls.Add(button1)
35    ' Add button2 to the form.
36    form1.Controls.Add(button2)
37   
38    ' Display the form as a modal dialog box.
39    form1.ShowDialog()
40   
41    ' Determine if the OK button was clicked on the dialog box.
42    If form1.DialogResult = DialogResult.OK Then
43        ' Display a message box indicating that the OK button was clicked.
44        MessageBox.Show("The OK button on the form was clicked.")
45        ' Optional: Call the Dispose method when you are finished with the dialog box.
46        form1.Dispose
47    ' Display a message box indicating that the Cancel button was clicked.
48    Else
49        MessageBox.Show("The Cancel button on the form was clicked.")
50        ' Optional: Call the Dispose method when you are finished with the dialog box.
51        form1.Dispose
52    End If
53End Sub 'CreateMyForm

 

---

ListView.Activation属性

Activation 属性允许您指定用户激活 ListView 控件中的项的方式。激活 ListView 中的项与只选择项是不同的。当激活某个项时，通常会在 ItemActivate 事件的事件处理程序中执行一个操作。例如，当激活某个项时，您可能会打开一个文件或显示一个允许用户对项进行编辑的对话框。通常，项的激活是通过用户对它进行双击来实现的。如果 Activation 属性设置为 ItemActivation.OneClick，那么单击该项一次即可将其激活。将 Activation 属性设置为 ItemActivation.TwoClick 与标准的双击不同，这是因为两次单击之间的时间间隔可以是任意的。

注意   如果将 Activation 属性设置为 ItemActivation.OneClick 或 ItemActivation.TwoClick，则不管 LabelEdit 属性的值是什么，都不允许进行标签编辑。