android中使用下拉列表、圖像按鈕時的常見問題

北京信息職業(yè)技術(shù)學(xué)院|范美英Android中使用下拉列表、圖像按鈕時的常見問題問題描述1如何實現(xiàn)點擊圖像按鈕時顯示類似左右圖所示的效果？Android中使用下拉列表、圖像按鈕時的常見問題|問題描述問題解決方案1思路介紹：在Java中為圖片按鈕增加觸摸監(jiān)聽的函數(shù)來實現(xiàn)圖片切換。具體地，當(dāng)圖片按下時，修改按鈕的背景圖片，當(dāng)抬起時再修改為正常的圖片顯示，代碼如左。Android中使用下拉列表、圖像按鈕時的常見問題|問題解決方案ImageButton

btn

=

(ImageButton)findViewById(R.id.imageButton1);

btn.setOnTouchListener(new

View.OnTouchListener(){

public

boolean

onTouch(View

v,

MotionEvent

event)

{

if(event.getAction()

==

MotionEvent.ACTION_DOWN){

//重新設(shè)置按下時的背景圖片

((ImageButton)v).setImageDrawable(getResources().getDrawable(R.drawable.android_btn_pressed));

}else

if(event.getAction()

==

MotionEvent.ACTION_UP){

//再修改為抬起時的正常圖片

((ImageButton)v).setImageDrawable(getResources().getDrawable(R.drawable.android_btn));

}

return

false;

}

});

問題解決方案2給按鈕配置XML文件來實現(xiàn)圖片按鈕的背景切換步驟1：在layout或drawable文件夾下添加一個image_btn_press.xml文件，代碼如左步驟2：在main.xml中設(shè)置圖片按鈕的屬性，將上面的xml文件添加到圖片按鈕的background屬性中，使用格式為：android:background="@layout/image_btn_press"Android中使用下拉列表、圖像按鈕時的常見問題|問題解決方案<?xml

version="1.0"

encoding="utf-8"?>

<selector

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

<item

android:state_pressed="false"

android:drawable="@drawable/android_btn"

/>

<item

android:state_focused="true"

android:drawable="@drawable/android_btn"

/>

<item

android:state_pressed="true"

android:drawable="@drawable/android_btn_pressed"

/>

</selector>

問題描述2如左圖所示，如何實現(xiàn)下拉列表的聯(lián)動？比如：當(dāng)?shù)?個下拉列表中選擇北京時，第2個列表的數(shù)據(jù)自動設(shè)置為北京的各區(qū)縣；當(dāng)?shù)?個下拉列表中選擇東城區(qū)時，第3個列表的數(shù)據(jù)自動設(shè)置為東城區(qū)的各個子區(qū)；Android中使用下拉列表、圖像按鈕時的常見問題|問題描述問題解決方案1//預(yù)設(shè)省級選項值privateString[]province=newString[]{"北京","上海","天津","廣東"};//,"重慶","黑龍江","江蘇","山東","浙江","香港","澳門"};//預(yù)設(shè)地級選項值

privateString[][]city=newString[][]{

{"東城區(qū)","西城區(qū)","崇文區(qū)","宣武區(qū)","朝陽區(qū)","海淀區(qū)","豐臺區(qū)","石景山區(qū)","門頭溝區(qū)","房山區(qū)","通州區(qū)","順義區(qū)","大興區(qū)","昌平區(qū)","平谷區(qū)","懷柔區(qū)","密云縣","延慶縣"},{"長寧區(qū)","靜安區(qū)","普陀區(qū)","閘北區(qū)","虹口區(qū)"},

{"和平區(qū)","河?xùn)|區(qū)","河西區(qū)","南開區(qū)","河北區(qū)","紅橋區(qū)","塘沽區(qū)","漢沽區(qū)","大港區(qū)","東麗區(qū)"},{"廣州","深圳","韶關(guān)","珠海","汕頭","佛山","湛江","肇慶","江門","茂名","惠州","梅州","汕尾","河源","陽江","清遠(yuǎn)","東莞","中山","潮州","揭陽","云浮"}Android中使用下拉列表、圖像按鈕時的常見問題|問題解決方案問題解決方案1 };//預(yù)設(shè)縣級選項值

privateString[][][]county=newString[][][]{{//北京

{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"}},{//上海

{"無"},{"無"},{"無"},{"無"},{"無"}},{//天津

{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"},{"無"}},Android中使用下拉列表、圖像按鈕時的常見問題|問題解決方案問題解決方案1{//廣東{"海珠區(qū)","荔灣區(qū)","越秀區(qū)","白云區(qū)","蘿崗區(qū)","天河區(qū)","黃埔區(qū)","花都區(qū)","從化市","增城市","番禺區(qū)",沙區(qū)"},//廣州

{"寶安區(qū)","福田區(qū)","龍崗區(qū)","羅湖區(qū)","南山區(qū)","鹽田區(qū)"},//深圳{"武江區(qū)","湞江區(qū)","曲江區(qū)","樂昌市","南雄市","始興縣","仁化縣","翁源縣","新豐縣","乳源縣"}//韶關(guān)}};Android中使用下拉列表、圖像按鈕時的常見問題|問題解決方案問題解決方案1Android中使用下拉列表、圖像按鈕時的常見問題|問題解決方案逐級設(shè)置問題解決方案1Android中使用下拉列表、圖像按鈕時的常見問題|問題解決方案逐級