Android開(kāi)發(fā)基礎(chǔ)與案例實(shí)戰(zhàn) 課件 童長(zhǎng)飛 第4、5章 菜單與對(duì)話框、多線程與網(wǎng)絡(luò)應(yīng)用

菜單與對(duì)話框

4.1任務(wù)1-使用選項(xiàng)菜單OptionsMenu21菜單的XML文件2選項(xiàng)菜單的創(chuàng)建方法3選項(xiàng)菜單的事件響應(yīng)方法OptionsMenuOptionsMenu不依賴于內(nèi)容，在應(yīng)用創(chuàng)建視圖時(shí)，OptionsMenu也被生成，常用于全局場(chǎng)合項(xiàng)目模板創(chuàng)建一個(gè)空白活動(dòng)頁(yè)面時(shí)，默認(rèn)沒(méi)有菜單文件夾，在創(chuàng)建OptionsMenu時(shí)，可利用向?qū)?chuàng)建相關(guān)文件夾和文件重要方法onCreateOptionsMenu()應(yīng)用首次生成選項(xiàng)菜單時(shí)調(diào)用，之后不再被調(diào)用，適合生成靜態(tài)菜單onPrepareOptionsMenu()沒(méi)次點(diǎn)擊選項(xiàng)菜單時(shí)被調(diào)用，適合生成動(dòng)態(tài)內(nèi)容的菜單項(xiàng)onOptionsItemSelected()選項(xiàng)菜單的點(diǎn)擊事件回調(diào)菜單XMLmenu根節(jié)點(diǎn)item節(jié)點(diǎn)為菜單項(xiàng)android:title菜單項(xiàng)在菜單中所顯示的文本android:icon菜單項(xiàng)的圖標(biāo)，須與app:showAsAction配合app:showAsAction屬性always：在動(dòng)作欄以圖標(biāo)形式顯示菜單項(xiàng)3相關(guān)布局文件4<!--OptionsMenu布局文件res/menu/opt_menu.xml-->

<menuxmlns:app="/apk/res-auto"

xmlns:android="/apk/res/android">

<item

android:id="@+id/opt_add"

android:icon="@drawable/ic_baseline_add_box_24"

android:title="增加"

app:showAsAction="always"/>

<item

android:id="@+id/opt_modify"

android:title="修改"/>

<item

android:id="@+id/opt_delete"

android:title="刪除"/>

</menu><vectorandroid:height="24dp"android:tint="#FFFFFF"

android:viewportHeight="24"android:viewportWidth="24"

android:width="24dp"xmlns:android="/apk/res/android">

<pathandroid:fillColor="#FF9800"android:pathData="M19,3L5,3c-1.11,0-2,0.9-2,2v14c0,1.10.89,22,2h14c1.1,02,-0.92,-2L21,5c0,-1.1-0.9,-2-2,-2zM17,13h-4v4h-2v-4L7,13v-2h4L11,7h2v4h4v2z"/>

</vector><!--my_main.xml-->

<LinearLayoutxmlns:android="/apk/res/android"

android:orientation="vertical"

android:layout_width="match_parent"

android:layout_height="match_parent">

<TextView

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="YournameandID"/>

<TextView

android:id="@+id/tv_result"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text=""/>

</LinearLayout>矢量圖文件，右擊res/drawable文件夾，new→VectorAsset選項(xiàng)創(chuàng)建實(shí)現(xiàn)MainActivity5publicclassMainActivityextendsAppCompatActivity{

TextViewtv;

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.my_main);

tv=findViewById(R.id.tv_result);

}

@Override

publicbooleanonCreateOptionsMenu(Menumenu){

getMenuInflater().inflate(R.menu.opt_menu,menu);

//將res/menu/opt_menu.xml菜單文件填充到menu對(duì)象上

//newMenuInflater(getApplicationContext()).inflate(R.menu.opt_menu,menu);

//也可以使用MenuInflater填充菜單

returnsuper.onCreateOptionsMenu(menu);

}

@Override

publicbooleanonOptionsItemSelected(@NonNullMenuItemitem){

Strings="";

//哪個(gè)選項(xiàng)菜單項(xiàng)被選中，建議使用菜單項(xiàng)的id進(jìn)行判斷

switch(item.getItemId()){

caseR.id.opt_add:

s="增加";

break;

caseR.id.opt_modify:

s="修改";

break;

caseR.id.opt_delete:

s="刪除";

break;

}

tv.setText(s);

returnsuper.onOptionsItemSelected(item);

}

}4.2任務(wù)2-使用上下文菜單ContextMenu61注冊(cè)上下文菜單2上下文菜單的創(chuàng)建和點(diǎn)擊響應(yīng)方法3上下文菜單獲取觸發(fā)位置4適配器數(shù)據(jù)的更新ContextMenuContextMenu依賴于內(nèi)容，需要注冊(cè)才能被使用調(diào)用registerForContextMenu()方法對(duì)UI對(duì)象注冊(cè)ContextMenu長(zhǎng)按被注冊(cè)的視圖，彈出上下文菜單重要方法onCreateContextMenu()每次彈出上下文菜單均會(huì)被調(diào)用onContextItemSelected(MenuItemitem)菜單項(xiàng)點(diǎn)擊事件回調(diào)若是針對(duì)ListView、GridView等組件，需要知道彈出上下文菜單的位置item.getMenuInfo()方法得到ContextMenuInfo對(duì)象無(wú)法得到position或者id信息須將ContextMenuInfo對(duì)象強(qiáng)制類型轉(zhuǎn)換成AdapterContextMenuInfo對(duì)象適配器視圖更新方法notifyDataSetChanged()方法一旦數(shù)據(jù)源的數(shù)據(jù)發(fā)生變化，需要調(diào)用適配器更新視圖，保持視圖與數(shù)據(jù)的一致性7項(xiàng)目的布局文件8<!--ContextMenu布局文件res/menu/ctx_menu.xml-->

<menuxmlns:app="/apk/res-auto"

xmlns:android="/apk/res/android">

<item

android:id="@+id/ctx_insert"

android:title="插入"/>

<item

android:id="@+id/ctx_delete"

android:title="刪除"/>

</menu><!--MainActivity的布局文件my_main.xml-->

<LinearLayoutxmlns:android="/apk/res/android"

android:orientation="vertical"

android:layout_width="match_parent"

android:layout_height="match_parent">

<TextView

android:id="@+id/tv_result"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="YournameandID"/>

<ListView

android:id="@+id/listView"

android:layout_width="match_parent"

android:layout_height="match_parent"/>

</LinearLayout>實(shí)現(xiàn)MainActivity9publicclassMainActivityextendsAppCompatActivity{

ArrayList<String>list=newArrayList<>();

ArrayAdapter<String>adapter;

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.my_main);

for(inti=0;i<20;i++){

Strings=String.format("Item%02d",i);

list.add(s);

}

adapter=newArrayAdapter<>(this,android.R.layout.simple_list_item_1,list);

ListViewlv=findViewById(R.id.listView);

lv.setAdapter(adapter);

registerForContextMenu(lv);

//對(duì)ListView視圖注冊(cè)ContextMenu，長(zhǎng)按ListView視圖會(huì)彈出ContextMenu

//若不注冊(cè)ContextMenu，則不會(huì)生成對(duì)應(yīng)菜單

}

@Override

publicvoidonCreateContextMenu(ContextMenumenu,Viewv,

ContextMenu.ContextMenuInfomenuInfo){

super.onCreateContextMenu(menu,v,menuInfo);

getMenuInflater().inflate(R.menu.ctx_menu,menu);

//將res/menu/ctx_menu.xml菜單生成到菜單對(duì)象menu上

}

@Override

publicbooleanonContextItemSelected(@NonNullMenuItemitem){

ContextMenu.ContextMenuInfomenuInfo=item.getMenuInfo();

//通過(guò)item獲得菜單項(xiàng)對(duì)象ContextMenuInfo

AdapterView.AdapterContextMenuInfoadapterContextMenuInfo=

(AdapterView.AdapterContextMenuInfo)menuInfo;

//將ContextMenuInfo對(duì)象強(qiáng)制類型轉(zhuǎn)換為AdapterContextMenuInfo

//通過(guò)AdapterContextMenuInfo獲得位置信息position

intposition=adapterContextMenuInfo.position;

switch(item.getItemId()){

caseR.id.ctx_insert:

Strings=String.format("Random:%d",newRandom().nextInt(1000));

//產(chǎn)生一個(gè)區(qū)間為[0,1000)的隨機(jī)整數(shù)（不包括1000）

list.add(position,s);//數(shù)據(jù)源插入數(shù)據(jù)s至指定位置position

adapter.notifyDataSetChanged();

//數(shù)據(jù)源發(fā)生變化，通知適配器數(shù)據(jù)更新，適配器全盤(pán)更新

break;

caseR.id.ctx_delete:

list.remove(position);//數(shù)據(jù)源刪除指定位置position的數(shù)據(jù)

adapter.notifyDataSetChanged();//通知適配器更新視圖

break;

}

returnsuper.onContextItemSelected(item);

}

}4.3任務(wù)3-使用彈出菜單PopupMenu101上下文菜單的局限性2PopupMenu可以實(shí)現(xiàn)多視圖注冊(cè)3PopupMenu的使用方法項(xiàng)目的布局文件11<!--TextView的菜單文件res/menu/ctx_tv_menu.xml-->

<menuxmlns:app="/apk/res-auto"

xmlns:android="/apk/res/android">

<item

android:id="@+id/ctx_tv_12"

android:title="12sp"/>

<item

android:id="@+id/ctx_tv_16"

android:title="16sp"/>

</menu><!--ContextMenu布局文件res/menu/ctx_menu.xml-->

<menuxmlns:app="/apk/res-auto"

xmlns:android="/apk/res/android">

<item

android:id="@+id/ctx_insert"

android:title="插入"/>

<item

android:id="@+id/ctx_delete"

android:title="刪除"/>

</menu><!--MainActivity的布局文件my_main.xml-->

<LinearLayoutxmlns:android="/apk/res/android"

android:orientation="vertical"

android:layout_width="match_parent"

android:layout_height="match_parent">

<TextView

android:id="@+id/tv_result"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="YournameandID"/>

<ListView

android:id="@+id/listView"

android:layout_width="match_parent"

android:layout_height="match_parent"/>

</LinearLayout>基于上下文菜單的雙視圖注冊(cè)12publicclassMainActivityextendsAppCompatActivity{

ArrayList<String>list=newArrayList<>();

ArrayAdapter<String>adapter;

ListViewlv;

TextViewtv;

intctx_position=0;//設(shè)置ContextMenu觸發(fā)位置的變量為全局變量

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.my_main);

for(inti=0;i<20;i++){

Strings=String.format("Item%02d",i);

list.add(s);

}

adapter=newArrayAdapter<>(this,android.R.layout.simple_list_item_1,list);

lv=findViewById(R.id.listView);

lv.setAdapter(adapter);

registerForContextMenu(lv);//對(duì)ListView視圖注冊(cè)ContextMenu

tv=findViewById(R.id.tv_result);

registerForContextMenu(tv);//對(duì)TextView視圖注冊(cè)ContextMenu

}

@Override

publicvoidonCreateContextMenu(ContextMenumenu,Viewv,

ContextMenu.ContextMenuInfomenuInfo){

super.onCreateContextMenu(menu,v,menuInfo);

if(v==lv){

//若是ListView，生成對(duì)應(yīng)菜單，并獲得位置信息賦給ctx_position

getMenuInflater().inflate(R.menu.ctx_menu,menu);

AdapterView.AdapterContextMenuInfoadapterContextMenuInfo=

(AdapterView.AdapterContextMenuInfo)menuInfo;

ctx_position=adapterContextMenuInfo.position;

}elseif(v==tv){

//若是TextView，生成另一種菜單

getMenuInflater().inflate(R.menu.ctx_tv_menu,menu);

}

}

@Override

publicbooleanonContextItemSelected(@NonNullMenuItemitem){

//TextView觸發(fā)的ContextMenu對(duì)象對(duì)應(yīng)的menuInfo是null，無(wú)position屬性

intposition=ctx_position;

//ctx_position在onCreateContextMenu()方法中被賦值

switch(item.getItemId()){

caseR.id.ctx_insert:

Strings=String.format("Random:%d",newRandom().nextInt(1000));

list.add(position,s);

adapter.notifyDataSetChanged();

break;

caseR.id.ctx_delete:

list.remove(position);

adapter.notifyDataSetChanged();

caseR.id.ctx_tv_12:

tv.setTextSize(12.0f);//設(shè)置文本字體大小

break;

caseR.id.ctx_tv_16:

tv.setTextSize(16.0f);

break;

}

returnsuper.onContextItemSelected(item);

}

}PopupMenu使用要點(diǎn)PopupMenu的構(gòu)造方法publicPopupMenu(android.content.Contextcontext,android.view.Viewanchor)context為上下文，可通過(guò)傳遞Activity對(duì)象或者直接通過(guò)getApplicationContext()方法獲得anchor為PopupMenu所依賴的視圖，即可理解為PopupMenu所需要注冊(cè)的視圖構(gòu)造出PopupMenu的對(duì)象popupMenu，使用popupMenu實(shí)現(xiàn)菜單填充和事件處理菜單填充popupMenu.getMenuInflater()方法得到菜單填充器，進(jìn)而通過(guò)菜單填充器的inflate()方法填充菜單popupMenu.getMenu()方法獲得Menu對(duì)象需要調(diào)用show()方法進(jìn)行顯示事件處理PopupMenu對(duì)象調(diào)用setOnMenuItemClickListener()方法設(shè)置偵聽(tīng)器onMenuItemClick()回調(diào)方法中進(jìn)行處理PopupMenu可以對(duì)不同視圖分別注冊(cè)，得到不同的PopupMenu對(duì)象，并分別對(duì)之進(jìn)行菜單填充和事件偵聽(tīng)處理，提高代碼解耦性13基于PopupMenu的實(shí)現(xiàn)14publicclassMainActivityextendsAppCompatActivity{

ArrayList<String>list=newArrayList<>();

ArrayAdapter<String>adapter;

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.my_main);

for(inti=0;i<20;i++){

Strings=String.format("Item%02d",i);

list.add(s);

}

adapter=newArrayAdapter<>(this,

android.R.layout.simple_list_item_1,list);

ListViewlv=findViewById(R.id.listView);

lv.setAdapter(adapter);

registerForContextMenu(lv);//對(duì)ListView視圖注冊(cè)ContextMenu

TextViewtv=findViewById(R.id.tv_result);

tv.setOnLongClickListener(newView.OnLongClickListener(){

//利用對(duì)象tv長(zhǎng)按彈出PopupMenu

@Override

publicbooleanonLongClick(Viewv){

showTextViewPopUpMenu(tv);//自定義方法，顯示PopupMenu

returntrue;//true表示長(zhǎng)按事件不再往下傳，false則繼續(xù)往下傳遞事件

}

});

}

privatevoidshowTextViewPopUpMenu(TextViewv){

PopupMenupopupMenu=newPopupMenu(getApplicationContext(),v);

//對(duì)視圖v生成菜單對(duì)象popupMenu

popupMenu.getMenuInflater()

.inflate(R.menu.ctx_tv_menu,popupMenu.getMenu());

//利用菜單對(duì)象popupMenu的getMenuInflater()方法獲得對(duì)應(yīng)菜單填充器

//利用菜單對(duì)象popupMenu的getMenu()方法獲得Menu對(duì)象menu

popupMenu.setOnMenuItemClickListener(

newPopupMenu.OnMenuItemClickListener(){

//對(duì)popupMenu設(shè)置菜單項(xiàng)點(diǎn)擊偵聽(tīng)

@Override

publicbooleanonMenuItemClick(MenuItemitem){

switch(item.getItemId()){

caseR.id.ctx_tv_12:

v.setTextSize(12.0f);

break;

caseR.id.ctx_tv_16:

v.setTextSize(16.0f);

break;

}

returntrue;//true表示菜單項(xiàng)選中事件不再往下傳，false則繼續(xù)下傳

}

});

popupMenu.show();//調(diào)用show()方法顯示PopupMenu

}

@Override

publicvoidonCreateContextMenu(ContextMenumenu,Viewv,

ContextMenu.ContextMenuInfomenuInfo){

…

}

@Override

publicbooleanonContextItemSelected(@NonNullMenuItemitem){

…

}

}4.4任務(wù)4-使用對(duì)話框AlertDialog151消息對(duì)話框2列表對(duì)話框3單選對(duì)話框?qū)υ捒駻lertDialog的使用要點(diǎn)AlertDialog使用AlertDialog.Builder()方法創(chuàng)建1個(gè)Builder對(duì)象setTitle()方法設(shè)置對(duì)話框標(biāo)題setMessage()方法設(shè)置對(duì)話框的文本內(nèi)容setItems()方法設(shè)置列表數(shù)據(jù)和點(diǎn)擊偵聽(tīng)setSingleChoiceItems()方法設(shè)置單選數(shù)據(jù)、默認(rèn)選中位置和點(diǎn)擊偵聽(tīng)setView()方法設(shè)置自定義視圖，此時(shí)建議使用LayoutInflater從布局文件中生成視圖對(duì)象setMultiChoiceItems()方法設(shè)置多選內(nèi)容、多選默認(rèn)選中的數(shù)據(jù)和相關(guān)偵聽(tīng)事件setAdapter()方法設(shè)置適配器setCursor()方法設(shè)置Cursor數(shù)據(jù)，Cursor為數(shù)據(jù)庫(kù)查詢返回的游標(biāo)setIcon()方法設(shè)置圖標(biāo)show()方法顯示對(duì)話框?qū)υ捒虻陌粹o設(shè)置方法setPositiveButton()方法設(shè)置確定按鈕setNegativeButton()方法設(shè)置取消按鈕setNeutralButton()方法設(shè)置中間按鈕第1個(gè)參數(shù)是按鈕所顯示的文本第2個(gè)參數(shù)是對(duì)應(yīng)的點(diǎn)擊事件接口，若不需要處理點(diǎn)擊事件，可傳入null16項(xiàng)目的布局文件my_main.xml17<LinearLayoutxmlns:android="/apk/res/android"

android:orientation="vertical"

android:layout_width="match_parent"

android:layout_height="match_parent">

<TextView

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="YournameandID"/>

<TextView

android:id="@+id/tv_result"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text=""/>

<Button

android:id="@+id/bt1"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="消息對(duì)話框"/>

<Button

android:id="@+id/bt2"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="列表對(duì)話框"/>

<Button

android:id="@+id/bt3"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="單選對(duì)話框"/>

</LinearLayout>實(shí)現(xiàn)MainActivity18publicclassMainActivityextendsAppCompatActivity{

TextViewtv;

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.my_main);

tv=findViewById(R.id.tv_result);

String[]hobbies=newString[]{"游泳","跑步","籃球"};

findViewById(R.id.bt1).setOnClickListener(newView.OnClickListener(){

@Override

publicvoidonClick(Viewv){

showMessageDialog("這是一個(gè)消息提示框");

}

});

findViewById(R.id.bt2).setOnClickListener(newView.OnClickListener(){

@Override

publicvoidonClick(Viewv){

showItemsDialog(hobbies);

}

});

findViewById(R.id.bt3).setOnClickListener(newView.OnClickListener(){

@Override

publicvoidonClick(Viewv){

showSingleChoiceDialog(hobbies);

}

});

}

privatevoidshowMessageDialog(Strings){

AlertDialog.Builderbl=newAlertDialog.Builder(this);

bl.setTitle("消息提示框").setMessage(s);

bl.setNegativeButton("退出",null);//退出按鈕，null代表不對(duì)事件響應(yīng)做處理

bl.show();

}

privatevoidshowItemsDialog(String[]hobbies){

AlertDialog.Builderbl=newAlertDialog.Builder(this);

bl.setTitle("列表框").setItems(hobbies,

newDialogInterface.OnClickListener(){

@Override

publicvoidonClick(DialogInterfacedialog,intwhich){

//每次點(diǎn)擊列表項(xiàng)均會(huì)更新TextView

Stringhobby=hobbies[which];

//若要在PositiveButton點(diǎn)擊事件中獲得hobby

//不借助全局變量或者自定義類，難以實(shí)現(xiàn)

tv.setText(hobby);

}

});

bl.setNegativeButton("退出",null);

bl.show();

}實(shí)現(xiàn)MainActivity（續(xù)）19

privatevoidshowSingleChoiceDialog(String[]hobbies){

//finalintchoiceIndex=0;//無(wú)法實(shí)現(xiàn)，final變量不能被二次賦值

//finalIntegerchoiceIndex=newInteger(0);

//無(wú)法實(shí)現(xiàn)，Integer類沒(méi)有setter相關(guān)方法

finalMyIntegermyInteger=newMyInteger(0);

//不加final無(wú)法在匿名回調(diào)方法中被訪問(wèn)

//通過(guò)自定義類解決int類型的final變量不能二次賦值問(wèn)題

//myInteger不能重新指向new對(duì)象，但可以調(diào)用類方法對(duì)類成員改值

AlertDialog.Builderbl=newAlertDialog.Builder(this);

bl.setTitle("單選對(duì)話框");

bl.setSingleChoiceItems(hobbies,myInteger.getPosition(),

newDialogInterface.OnClickListener(){

@Override

publicvoidonClick(DialogInterfacedialog,intwhich){

//showMessageDialog("inside");//測(cè)試對(duì)話框中是否能生成另一個(gè)對(duì)話框

myInteger.setPosition(which);

//通過(guò)setPosition()方法給類成員變量重新賦值

}

});

bl.setPositiveButton("確定",newDialogInterface.OnClickListener(){

//點(diǎn)擊確定按鈕，在回調(diào)中處理確定按鈕對(duì)應(yīng)的邏輯,更新愛(ài)好選項(xiàng)到TextView

@Override

publicvoidonClick(DialogInterfacedialog,intwhich){

//從自定義類對(duì)象myInteger中取選中索引值

intposition=myInteger.getPosition();

tv.setText(hobbies[position]);

}

});

bl.setNegativeButton("退出",null);

bl.show();

}

classMyInteger{

//定義一個(gè)內(nèi)部類解決final問(wèn)題

//類對(duì)象變成final，不能重新指向?qū)ο?，但是可以調(diào)用類的相

//關(guān)方法改變類成員變量的值

privateintposition=0;

publicMyInteger(intposition){

this.position=position;

}

publicintgetPosition(){

returnposition;

}

publicvoidsetPosition(intposition){

this.position=position;

}

}

}通過(guò)自定義類實(shí)現(xiàn)final變量的賦值問(wèn)題4.5任務(wù)5-使用自定義視圖對(duì)話框201自定義視圖的使用方法2利用自定義接口提高代碼的解耦性3使用對(duì)話框新增修改數(shù)據(jù)項(xiàng)目的布局文件21<!--MainActivity的布局文件my_main.xml-->

<LinearLayoutxmlns:android="/apk/res/android"

android:orientation="vertical"

android:layout_width="match_parent"

android:layout_height="match_parent">

<TextView

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="YournameandID"/>

<ListView

android:id="@+id/listView"

android:layout_width="match_parent"

android:layout_height="match_parent"/>

</LinearLayout><!--ContextMenu菜單文件res/menu/ctx_menu.xml-->

<menuxmlns:android="/apk/res/android"

xmlns:app="/apk/res-auto">

<item

android:id="@+id/ctx_add"

android:title="新增"/>

<item

android:id="@+id/ctx_edit"

android:title="修改"/>

</menu><!--AlertDialog自定義視圖res/layout/dialog_view.xml-->

<LinearLayoutxmlns:android="/apk/res/android"

android:orientation="vertical"

android:layout_width="match_parent"

android:layout_height="match_parent">

<EditText

android:id="@+id/dialog_et_name"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:ems="10"

android:hint="Inputyourname"

android:text=""/>

<EditText

android:id="@+id/dialog_et_phone"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:ems="10"

android:hint="Inputyourphonenumber"

android:text=""/>

</LinearLayout>數(shù)據(jù)封裝類PhoneData22publicclassPhoneData{

privateStringname;

privateStringphone;

publicPhoneData(Stringname,Stringphone){

this.name=name;

this.phone=phone;

}

publicStringgetName(){

returnname;

}

publicvoidsetName(Stringname){

this.name=name;

}

publicStringgetPhone(){

returnphone;

}

publicvoidsetPhone(Stringphone){

this.phone=phone;

}

@Override

publicStringtoString(){

//必須改寫(xiě)toString()方法，否則無(wú)法將PhoneData字符串化顯示在適配器中

returnString.format("%s%s",name,phone);

}

}未改寫(xiě)toString()，ArrayAdapter顯示效果實(shí)現(xiàn)自定義視圖對(duì)話框PhoneDataDialog23publicclassPhoneDataDialog{

privateContextcontext;//LayoutInflater需要Context參數(shù)

privateStringtitle;//對(duì)話框標(biāo)題

publicinterfaceOnSubmitListener{//自定義一個(gè)接口

voidonSubmit(PhoneDataupdatedData);

//通過(guò)用戶實(shí)現(xiàn)接口的onSubmit()方法對(duì)updatedData進(jìn)行處理

//使用updatedData修改數(shù)據(jù)或者新增數(shù)據(jù)完全取決于用戶實(shí)現(xiàn)的代碼

//接口回調(diào)在對(duì)話框的確定按鈕中觸發(fā)

}

publicPhoneDataDialog(Contextcontext,Stringtitle){

this.context=context;

this.title=title;

}

publicvoidshowDialog(PhoneDatadata,OnSubmitListenerl){

/***

data數(shù)據(jù)是用戶傳進(jìn)來(lái)的待修改數(shù)據(jù)，若是新增數(shù)據(jù)，可傳null

OnSubmitListener是用戶實(shí)現(xiàn)的接口，在確定按鈕中觸發(fā)回調(diào)，

通過(guò)onSubmit(PhoneDataupdatedData)傳出修改后的數(shù)據(jù)updatedData

用戶則在調(diào)用showDialog()時(shí)實(shí)現(xiàn)回調(diào)方法，對(duì)updatedData處理（新增或者修改）

*/

PhoneDatatemp=newPhoneData("","");

if(data!=null){//若data不為空，則將值賦給變量temp

temp.setName(data.getName());

temp.setPhone(data.getPhone());

}

Viewv=LayoutInflater.from(context)

.inflate(R.layout.dialog_view,null,false);

//將布局文件填充為視圖對(duì)象v

EditTextet_name=v.findViewById(R.id.dialog_et_name);

EditTextet_phone=v.findViewById(R.id.dialog_et_phone);

//對(duì)兩個(gè)EditText賦data傳進(jìn)的初值

et_name.setText(temp.getName());

et_phone.setText(temp.getPhone());

AlertDialog.Builderbl=newAlertDialog.Builder(context);

bl.setTitle(title);

bl.setView(v);//將XML布局填充的視圖對(duì)象v設(shè)置為對(duì)話框的內(nèi)容

bl.setNegativeButton("取消",null);

bl.setPositiveButton("確定",newDialogInterface.OnClickListener(){

@Override

publicvoidonClick(DialogInterfacedialog,intwhich){

PhoneDataupdatedData=newPhoneData(

et_name.getText().toString(),

et_phone.getText().toString());

//不直接修改變量data

//使用updatedData的目的是data可能是null

if(l!=null){//判斷接口非空才能設(shè)置自定義接口回調(diào)

l.onSubmit(updatedData);

}

}

});

bl.show();

}

}實(shí)現(xiàn)MainActivity24publicclassMainActivityextendsAppCompatActivity{

ArrayList<PhoneData>list=newArrayList<>();

ArrayAdapter<PhoneData>adapter;

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.my_main);

ListViewlv=findViewById(R.id.listView);

for(inti=0;i<4;i++){//模擬了8個(gè)PhoneData數(shù)據(jù)

list.add(newPhoneData("張三",));

list.add(newPhoneData("李四",));

}

adapter=newArrayAdapter<>(this,

android.R.layout.simple_list_item_1,list);

lv.setAdapter(adapter);

registerForContextMenu(lv);

}

@Override

publicvoidonCreateContextMenu(ContextMenumenu,Viewv,

ContextMenu.ContextMenuInfomenuInfo){

super.onCreateContextMenu(menu,v,menuInfo);

getMenuInflater().inflate(R.menu.ctx_menu,menu);//生成ContextMenu

}

@Override

publicbooleanonContextItemSelected(@NonNullMenuItemitem){