2. 如何在.NET的Windows窗体上启用XP主题集？（How to use XP Themes with Windows Forms using the .NET?）

确认你的控件中FlatStyle属性已经修改为System，再修改Main方法。

static void Main()
{
Application.EnableVisualStyles();
Application.DoEvents();
Application. Run(new Form1());
}

3. 如何为一个窗体设置一个默认按钮？（How to set the default button for a form?）

form1.AcceptButton = button1;

4. 如何为一个窗体设置一个取消按钮？（How to set the Cancel button for a form?）

form1.CancelButton = button1;

5. 如何阻止一个窗体标题显示在任务栏上？（How to prevent a form from being shown in the taskbar?）

设置窗体的ShowIntaskbar属性为False

6. 如何用现有可用字体绑定到ComboBox控件？（How to fill a ComboBox with the available fonts?）

comboBox1.Items.AddRange (FontFamily.Families);

7. 如何禁止TextBox控件默认的邮件菜单？（How to disable the default ContextMenu of a TextBox?）

textBox1.ContextMenu = new ContextMenu ();

8. 如何获取“我的文档”等一些系统文件夹路径？（How to get the path for "My Documents" and other system folders?）

Environment.SpecialFolder中包含了一些系统文件夹信息
MessageBox.Show(Environment.GetFolderPath( Environment.SpecialFolder.Personal ));

9. 如何获取应用程序当前执行的路径？（How to get the path to my running EXE?）

string appPath = Application.ExecutablePath;

10. 如何确定当前运行的系统？（How to determine which operating system is running?）

OperatingSystem os = Environment.OSVersion;
MessageBox.Show(os.Version.ToString());
MessageBox.Show(os.Platform.ToString());

11. 如何从完整的路径中获取文件名？（How to get a file's name from the complete path string?）

用System.IO.Path.GetFileName 和 System.IO.Path.GetFileNameWithoutExtension（无扩展名）的方法

12. 如何从完整的路径中获取文件扩展名？（How to get a file's extension from the complete path string?）

用System.IO.Path.GetExtension方法

13. 如何使没有选择日期的DateTimePicker控件为空文本？（How to make the DateTimePicker show empty text if no date is selected?）

dateTimePicker1.CustomFormat = " ";
dateTimePicker1.Format = DateTimePickerFormat.Custom;

14. 如何在Report Viewer中隐藏Crystal Report的状态栏？（How to hide the status bar of Crystal Report in Report Viewer?）

foreach(object obj in this.crystalReportViewer1.Controls)
{
if( obj.GetType()== typeof(System.Windows.Forms.StatusBar))
{
StatusBar sBar=(StatusBar)obj;
sBar.Visible=false;
}
}

15. 如何利用Crystal Report程序来生成PDF版本？（How to generate PDF version of Crystal Report programmatically?）

ReportDocument O_Report=new ReportDocument();
ExportOptions exportOpts = new ExportOptions();
PdfRtfWordFormatOptions pdfFormatOpts = new PdfRtfWordFormatOptions ();
DiskFileDestinationOptions diskOpts = new DiskFileDestinationOptions();
exportOpts = O_Report.ExportOptions;
// 设置PDF格式
exportOpts.ExportFormatType = ExportFormatType.PortableDocFormat;
exportOpts.FormatOptions = pdfFormatOpts;
// 设置文件选项和导出
exportOpts.ExportDestinationType = ExportDestinationType.DiskFile;
diskOpts.DiskFileName = "C://Trial.pdf"; //设置PDF导出路径
exportOpts.DestinationOptions = diskOpts;
O_Report.Export ();

16.通过代码如何输入多行文本？（How to enter multiline text in textbox through code? ）

利用TextBox控件的LINES属性
string [] strAddress = {"Mukund Pujari","Global Transformation Technologies","Pune, India"};
textBox1.MultiLine=true;
textBox1.Lines=strAddress;

或者
textBox1.Text="Line 1\r\nLine2\r\nLine3.";

或者
用"System.Environment.NewLine"来替代换行符号

17. 如何在DataGrid中去掉CheckBox不确定状态？（How to remove the indeterminate status of checkbox in datagrid?）

DataGridTableStyle ts1 = new DataGridTableStyle(); //创