package com.id2ip; 
import android.app.Activity; 
import android.os.Bundle; 
import android.widget.*; 
import android.view.*; 
public class id2ip extends Activity { 
 /** Called when the activity is first created. */ 
 private TextView text; 
 private Button button; 
 @Override 
 public void onCreate(Bundle savedInstanceState) { 
 super.onCreate(savedInstanceState); 
 setContentView(R.layout.main); 
 //获得文本框ID 
 text = (TextView)findViewById(R.id.editText1); 
 //获得按钮ID 
 button = (Button)findViewById(R.id.button1); 
 //重载按键监听方法 
 button.setOnClickListener(new Button.OnClickListener() 
 { 
  @Override 
  public void onClick(View v) 
  { 
  //获得输入框文本 
  CharSequence str = text.getText(); 
  do 
  { 
   //判断输入是否有效 
   //如果输入位数不为8位,则无效 
   if (str.length() != 8) 
   { 
   text.setText("输入位数必须为8位"); 
   break; 
   } 
   //输入的字符不为数字,则无效 
   int i = 0; 
   for (i = 0;i < 8;i++) 
   { 
   if ((str.charAt(i) < '0') || (str.charAt(i) > '9')) 
   { 
    break; 
   } 
   } 
   if (i < 8) 
   { 
   text.setText("输入字符必须为数字"); 
   break; 
   } 
   String str_temp = str.toString(); 
   //转换为数字 
   long num = Long.parseLong(str_temp); 
   //ip2id 
   short slave_num = (short)(num / 1000000); 
   num = num % 1000000; 
   short ip1 = (short)(num / 1000); 
   num = num % 1000; 
   short ip0 = (short)num; 
   long num_temp = ip0; 
   num_temp |= ip1 << 8; 
   num_temp |= slave_num << 16; 
   str_temp = Long.toString(num_temp); 
   str = str_temp; 
   text.setText(str); 
  }while (false); 
  } 
 }); 
 } 
}

CharSequence str;
String str_temp = str.toString();

str = str_temp;