Android 中日期对话框的应用

 import java.util.Calendar;
 import android.widget.DatePicker;
 import android.app.DatePickerDialog;  

     //日期对话框的标记 常量
     private static final int DATE_DIALOG_ID = 1;
     private static final int SHOW_DATAPICK = 0;
     //日期变量
     private int mYear;
     private int mMonth;
     private int mDay;
     //当前操作的日期控件的标记
     private String strDate_Tag=""; 

     //购买日期
     private EditText m_txtPurchaseDate = null;
     private Button m_butPurchaseDate = null;
     //安装日期
     private EditText m_txtInstallationDate = null;
     private Button m_butInstallationDate = null;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //购买日期
        m_txtPurchaseDate = (EditText) findViewById(R.id.txtPurchaseDate);
        m_butPurchaseDate = (Button) findViewById(R.id.butPurchaseDate);
        //安装日期
        m_txtInstallationDate= (EditText) findViewById(R.id.txtInstallationDate);
        m_butInstallationDate = (Button) findViewById(R.id.butInstallationDate);

        initDate();//初始化 日期
    }

    //初始化 日期
    private void initDate(){

        final Calendar c = Calendar.getInstance();
        mYear = c.get(Calendar.YEAR);
        mMonth = c.get(Calendar.MONTH);
        mDay = c.get(Calendar.DAY_OF_MONTH);
        //setDateTime();//设置日期
        strDate_Tag="PurchaseDate";//购买日期
        setDateTime();
        strDate_Tag="InstallationDate";//安装日期
        setDateTime();
    }
    //设置日期   为文本框 赋值
    private void setDateTime() {
        if(strDate_Tag=="PurchaseDate"){//购买日期
            m_txtPurchaseDate.setText(new StringBuilder().append(mYear +"-").append(
                    (mMonth + 1) < 10 ? "0" + (mMonth + 1)+"-" : (mMonth + 1)+"-").append(
                    (mDay < 10) ? "0" + mDay : mDay));
        }else if(strDate_Tag=="InstallationDate"){//安装日期
            m_txtInstallationDate.setText(new StringBuilder().append(mYear +"-").append(
                    (mMonth + 1) < 10 ? "0" + (mMonth + 1)+"-" : (mMonth + 1)+"-").append(
                    (mDay < 10) ? "0" + mDay : mDay));
        }
    }  

    //日期控件的事件
    private DatePickerDialog.OnDateSetListener mDateSetListener = new DatePickerDialog.OnDateSetListener() {
       public void onDateSet(DatePicker view, int year, int monthOfYear,
              int dayOfMonth) {
           mYear = year;
           mMonth = monthOfYear;
           mDay = dayOfMonth;
           setDateTime();  //设置日期   为文本框 赋值
       }
    }; 

    //购买日期Button的事件处理
    class butPurchaseDateOnClickListener implements
           android.view.View.OnClickListener {
       public void onClick(View v) {
           strDate_Tag="PurchaseDate";//当前点击的日期为 购买日期

           String[] arrPurchaseDate =m_txtPurchaseDate.getText().toString().split("-");
           mYear =  Integer.parseInt(arrPurchaseDate[0]);
           mMonth = Integer.parseInt(arrPurchaseDate[1]);
           mDay = Integer.parseInt(arrPurchaseDate[2]);

           Message msg = new Message();
           if (m_butPurchaseDate.equals((Button) v)) {
              msg.what = MainActivity.SHOW_DATAPICK;
           }
           MainActivity.this.saleHandler.sendMessage(msg);
       }
    }
    //购买日期Button的事件处理
    class butInstallationDateOnClickListener implements
           android.view.View.OnClickListener {
       public void onClick(View v) {
           strDate_Tag="InstallationDate";//当前点击的日期为 安装日期

           String[] arrInstallationDate =m_txtInstallationDate.getText().toString().split("-");
           mYear =  Integer.parseInt(arrInstallationDate[0]);
           mMonth = Integer.parseInt(arrInstallationDate[1]);
           mDay = Integer.parseInt(arrInstallationDate[2]);

           Message msg = new Message();
           if (m_butInstallationDate.equals((Button) v)) {
              msg.what = MainActivity.SHOW_DATAPICK;
           }
           MainActivity.this.saleHandler.sendMessage(msg);
       }
    }

    //创建对话框 日期
    protected Dialog onCreateDialog(int id) {
       switch (id) {
       case DATE_DIALOG_ID:  //日期
           return new DatePickerDialog(this, mDateSetListener, mYear, mMonth,  mDay);
       }
       return null;
    }  

    protected void onPrepareDialog(int id, Dialog dialog) {
       switch (id) {
       case DATE_DIALOG_ID:
           ((DatePickerDialog) dialog).updateDate(mYear, mMonth, mDay);
           break;
       }
    }  

    //处理日期控件的Handler
    Handler saleHandler = new Handler() {
       @Override
       public void handleMessage(Message msg) {
           switch (msg.what) {
           case MainActivity.SHOW_DATAPICK:
              showDialog(DATE_DIALOG_ID);
              break;
           }
       }
    };