ch07 Android(安卓)回调方法

--------------------------------------------CallUp.java-------------------------------------

packagecom.ch07.callback;

/**

*项目名称：com.ch07.callback

*类名称：CallUp

*类描述：打电话类

*创建人：fy

*创建时间：2012-11-9下午6:28:38

publicclassCallUp{

/*打电话,回调方法*/

publicvoidcallme(OnCallBackonCallBack){

onCallBack.execute();

}

/*接口作为参数传递*/

publicinterfaceOnCallBack{

voidexecute();

}

--------------------------------------------TestCall.java-------------------------------------

packagecom.ch07.callback;

/**

*场景描述：

*java回调函数

*什么是回调？(What)

*精妙比喻：我把手机号码给你，你通过手机号码联系我

*具体解释：

*我把我的手机号码给你，你通过电话号码打电话联系我

*我把我的手机号码给你，你通过电话号码发短信联系我

*共同的部分：

*我把我的手机号码给你，你通过电话号码(****)联系我

*不同的部分

*每次在使用的时候，选择是打电话或是发短信。

*回调都做了什么？

*将变动与不变的代码分离，变动的代码在每次使用时确认

*什么情况使用回调？为什么要使用回调？

*步骤固定，但有一部分内容只有在使用的时候才能知道。

publicclassTestCall{

publicstaticvoidmain(String[]args){

/*实例化电话类*/

CallUpcallUp=newCallUp();

/*拨打对方的电话,只需要知道对方的手机号码*/

callUp.callme(newCallUp.OnCallBack(){

@Override

publicvoidexecute(){

System.out.println("回调方法");

}

});

}

--------------------------------------------DatePickerDialog.java---------------------------------

*LicensedundertheApacheLicense,Version2.0(the"License");

*youmaynotusethisfileexceptincompliancewiththeLicense.

*YoumayobtainacopyoftheLicenseat

*http://www.apache.org/licenses/LICENSE-2.0

*Unlessrequiredbyapplicablelaworagreedtoinwriting,software

*distributedundertheLicenseisdistributedonan"ASIS"BASIS,

*WITHOUTWARRANTIESORCONDITIONSOFANYKIND,eitherexpressorimplied.

*SeetheLicenseforthespecificlanguagegoverningpermissionsand

*limitationsundertheLicense.

packageandroid.app;

importandroid.content.Context;

importandroid.content.DialogInterface;

importandroid.content.DialogInterface.OnClickListener;

importandroid.os.Bundle;

importandroid.text.format.DateUtils;

importandroid.view.LayoutInflater;

importandroid.view.View;

importandroid.widget.DatePicker;

importandroid.widget.DatePicker.OnDateChangedListener;

importcom.android.internal.R;

importjava.util.Calendar;

/**

*Asimpledialogcontainingan{@linkandroid.widget.DatePicker}.

*<p>Seethe<ahref="{@docRoot}resources/tutorials/views/hello-datepicker.html">DatePicker

*tutorial</a>.</p>

publicclassDatePickerDialogextendsAlertDialogimplementsOnClickListener,

OnDateChangedListener{

privatestaticfinalStringYEAR="year";

privatestaticfinalStringMONTH="month";

privatestaticfinalStringDAY="day";

privatefinalDatePickermDatePicker;

privatefinalOnDateSetListenermCallBack;

privatefinalCalendarmCalendar;

privatebooleanmTitleNeedsUpdate=true;

/**

*Thecallbackusedtoindicatetheuserisdonefillinginthedate.

publicinterfaceOnDateSetListener{

/**

*@paramviewTheviewassociatedwiththislistener.

*@paramyearTheyearthatwasset.

*@parammonthOfYearThemonththatwasset(0-11)forcompatibility

*with{@linkjava.util.Calendar}.

*@paramdayOfMonthThedayofthemonththatwasset.

voidonDateSet(DatePickerview,intyear,intmonthOfYear,intdayOfMonth);

}

/**

*@paramcontextThecontextthedialogistorunin.

*@paramcallBackHowtheparentisnotifiedthatthedateisset.

*@paramyearTheinitialyearofthedialog.

*@parammonthOfYearTheinitialmonthofthedialog.

*@paramdayOfMonthTheinitialdayofthedialog.

publicDatePickerDialog(Contextcontext,

OnDateSetListenercallBack,

intyear,

intmonthOfYear,

intdayOfMonth){

this(context,0,callBack,year,monthOfYear,dayOfMonth);

}

/**

*@paramcontextThecontextthedialogistorunin.

*@paramthemethethemetoapplytothisdialog

*@paramcallBackHowtheparentisnotifiedthatthedateisset.

*@paramyearTheinitialyearofthedialog.

*@parammonthOfYearTheinitialmonthofthedialog.

*@paramdayOfMonthTheinitialdayofthedialog.

publicDatePickerDialog(Contextcontext,

inttheme,

OnDateSetListenercallBack,

intyear,

intmonthOfYear,

intdayOfMonth){

super(context,theme);

mCallBack=callBack;

mCalendar=Calendar.getInstance();

ContextthemeContext=getContext();

setButton(BUTTON_POSITIVE,themeContext.getText(R.string.date_time_done),this);

setIcon(0);

LayoutInflaterinflater=

(LayoutInflater)themeContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

Viewview=inflater.inflate(R.layout.date_picker_dialog,null);

setView(view);

mDatePicker=(DatePicker)view.findViewById(R.id.datePicker);

mDatePicker.init(year,monthOfYear,dayOfMonth,this);

updateTitle(year,monthOfYear,dayOfMonth);

}

publicvoidonClick(DialogInterfacedialog,intwhich){

tryNotifyDateSet();

}

publicvoidonDateChanged(DatePickerview,intyear,

intmonth,intday){

mDatePicker.init(year,month,day,this);

updateTitle(year,month,day);

}

/**

*Getsthe{@linkDatePicker}containedinthisdialog.

*@returnThecalendarview.

publicDatePickergetDatePicker(){

returnmDatePicker;

}

/**

*Setsthecurrentdate.

*@paramyearThedateyear.

*@parammonthOfYearThedatemonth.

*@paramdayOfMonthThedatedayofmonth.

publicvoidupdateDate(intyear,intmonthOfYear,intdayOfMonth){

mDatePicker.updateDate(year,monthOfYear,dayOfMonth);

}

privatevoidtryNotifyDateSet(){

if(mCallBack!=null){

mDatePicker.clearFocus();

mCallBack.onDateSet(mDatePicker,mDatePicker.getYear(),

mDatePicker.getMonth(),mDatePicker.getDayOfMonth());

}

@Override

protectedvoidonStop(){

tryNotifyDateSet();

super.onStop();

}

privatevoidupdateTitle(intyear,intmonth,intday){

if(!mDatePicker.getCalendarViewShown()){

mCalendar.set(Calendar.YEAR,year);

mCalendar.set(Calendar.MONTH,month);

mCalendar.set(Calendar.DAY_OF_MONTH,day);

Stringtitle=DateUtils.formatDateTime(mContext,

mCalendar.getTimeInMillis(),

DateUtils.FORMAT_SHOW_DATE

|DateUtils.FORMAT_SHOW_WEEKDAY

|DateUtils.FORMAT_SHOW_YEAR

|DateUtils.FORMAT_ABBREV_MONTH

|DateUtils.FORMAT_ABBREV_WEEKDAY);

setTitle(title);

mTitleNeedsUpdate=true;

}else{

if(mTitleNeedsUpdate){

mTitleNeedsUpdate=false;

setTitle(R.string.date_picker_dialog_title);

}

@Override

publicBundleonSaveInstanceState(){

Bundlestate=super.onSaveInstanceState();

state.putInt(YEAR,mDatePicker.getYear());

state.putInt(MONTH,mDatePicker.getMonth());

state.putInt(DAY,mDatePicker.getDayOfMonth());

returnstate;

}

@Override

publicvoidonRestoreInstanceState(BundlesavedInstanceState){

super.onRestoreInstanceState(savedInstanceState);

intyear=savedInstanceState.getInt(YEAR);

intmonth=savedInstanceState.getInt(MONTH);

intday=savedInstanceState.getInt(DAY);

mDatePicker.init(year,month,day,this);

}

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