C#实现组合排列的方法

 public partial class FrmDemo : Form 
 {   
 public FrmDemo()    
 {       InitializeComponent();
 } 
 private void FrmDemo_Load( sender, EventArgs e)   
 {    
 string svn = "0b1de737-cea695ab-fc505423-bdd5f3db ";  
 bool ret = ZhuHeNum.Initia(svn);   
 if (!ret)       
 MessageBox.Show("注册失败！"); 
 } 
 private void btnNot2_Click( sender, EventArgs e)  
 {       string str = txtnot.Text;      
 List<string> list = ZhuHeNum.NumNoRepeAssembly(str, 2); 
 if (list == null)    
 {       
 MessageBox.Show("注册失败！");     
 return;    
 }     
 list.Sort();     
 StringBuilder sbBuilder = new StringBuilder();   
 foreach (string s in list) 
 {    
 sbBuilder.Append(s);     
 sbBuilder.Append("\r\n");       }  
 txtShow.Clear();      
 txtShow.Text = sbBuilder.ToString(); 
 lbCount.Text = list.Count.ToString();  
 }  
 private void btnNot3_Click( sender, EventArgs e)  
 {      
 string str = txtnot.Text;     
 List<string> list = ZhuHeNum.NumNoRepeAssembly(str, 3);  
 if (list == null)    
 {         MessageBox.Show("注册失败！");    
 return;     
 }     
 list.Sort();    
 StringBuilder sbBuilder = new StringBuilder();  
 foreach (string s in list)   
 {       
 sbBuilder.Append(s);  
 sbBuilder.Append("\r\n"); 
 }  
 txtShow.Clear();     
 txtShow.Text = sbBuilder.ToString();  
 lbCount.Text = list.Count.ToString();  
 }    
 private void btnAll2_Click( sender, EventArgs e)  
 {       string str = txtAll.Text;     
 List<string> list = ZhuHeNum.NumGroupAssembly(str, 2);  
 if (list == null)   
 {         MessageBox.Show("注册失败！"); 
 return;     
 }    
 list.Sort();     
 StringBuilder sbBuilder = new StringBuilder(); 
 foreach (string s in list)   
 {        
 sbBuilder.Append(s); 
 sbBuilder.Append("\r\n");       } 
 txtShow.Clear();     
 txtShow.Text = sbBuilder.ToString();  
 lbCount.Text = list.Count.ToString();
 }   
 private void btnAll3_Click( sender, EventArgs e) 
 {      
 string str = txtAll.Text; 
 List<string> list = ZhuHeNum.NumGroupAssembly(str, 3);  
 if (list == null)    
 {        
 MessageBox.Show("注册失败！");  
 return;     
 }  
 list.Sort();      
 StringBuilder sbBuilder = new StringBuilder();   
 foreach (string s in list)  
 {        
 sbBuilder.Append(s); 
 sbBuilder.Append("\r\n");  
 } 
 txtShow.Clear();      
 txtShow.Text = sbBuilder.ToString(); 
 lbCount.Text = list.Count.ToString(); 
 }  
 }