自定義view大概可以分成：
最近又跟同學(xué)聊起來了，于是就準(zhǔn)備自己實(shí)現(xiàn)一個imagebutton來練練手。（最簡單的了）以及后面一個把imageview與textview結(jié)合使用的案例。
ImageButton
要實(shí)現(xiàn)ImageButton最容易想到的不就是把button和imageview合在一起么。嗯，人容易就想到這是一個組合自定義view。可是如何把一個image放到button上呢，自然就是用一個FrameLayout把button和imageview包裹起來，然后將這個layout當(dāng)作一個weidgt。把一個layout當(dāng)成一個控件我開始不太理解。后來了解到一些東西。
補(bǔ)充知識點(diǎn)（安卓的頂層視圖）
在android里面，你的app界面的活動的視圖并非是最頂級的視圖。大家應(yīng)該都知道viewtree。在安卓里面，最頂級的視圖是一個叫DecorView的東西。它包括你的狀態(tài)欄，標(biāo)題欄，以及你的活動界面。而且這個活動界面，安卓會自動幫你提前弄進(jìn)去一個FrameLayout?？梢赃@么理解吧，在安卓這個上帝的面前，你的activity就是放在他的framelayout的一個個view。上一張圖～
DecorView->LinearLayout(狀態(tài)欄和activity)->FrameLayout(activity)->你自己的acitivty視圖。
實(shí)例講解
好啦，回歸正題。我上代碼了。
myimagebutton_layout.xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/button_imagebutton" /> <ImageView android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/imageview_button" /></FrameLayout>
用一個framelayout把兩個控件裝起來，然后組合。組合了之后我們就去自定義我們這個控件的屬性。button不用變對吧，用原生的就好了，就是需要有一個圖片的src這個屬性就好了。
在values目錄下的attrs.xml文件_
<?xml version="1.0" encoding="utf-8"?><resources>在 <declare-styleable name="MyImageButton"> <attr name="Imagesrc" format="reference"/> </declare-styleable></resources>
一般來說，declare-styleable標(biāo)簽的名字都是你的自定義控件的名字。attr就是你的自定義控件屬性。format是這個屬性的值的數(shù)據(jù)類型。這里的reference表示引用。dimension表示的是dp或者sp的大小。還有一些可以自己去看看。定義好屬性，我們就開始寫控件了。
MyImageButton.java
public class MyImageButton2 extends FrameLayout{ ImageView mImageView; Button mButton; int resId; public MyImageButton2(Context context) { super(context); } public MyImageButton2(Context context, AttributeSet attrs) { super(context, attrs); //導(dǎo)入布局 LayoutInflater.from(context).inflate(R.layout.myimagebutton_layout, this); mImageView＝(ImageView)findViewById(R.id.imageview_button); mButton = (Button) findViewById(R.id.button_imagebutton); //獲得這個控件對應(yīng)的屬性。 TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.MyImageButton); try{ //獲得屬性值 resId = a.getResourceId(R.styleable.MyImageButton_Imagesrc, 0); }finally { //回收這個對象 a.recycle(); } if(resId != 0){ mImageView.setImageResource(resId); } } public void setImage(int resId){ mImageView.setImageResource(resId); }}一般來說，繼承view（就這么說吧，反正都是都是繼承view的），實(shí)現(xiàn)兩三個構(gòu)造函數(shù)就可以了。在第二個里面有一個attr，這就是傳進(jìn)來的屬性。如果resId不為默認(rèn)值，就表示用戶在xml里面?zhèn)魅肓诉@個屬性值，你也必須要寫一個set方法，讓用戶可以在java代碼中去改變屬性值。
test.myimagebutton.layout.xml_
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <com.example.think.testview.customview.MyImageButton2 xmlns:pt = "http://schemas.android.com/apk/res/com.example.think.testview" android:layout_height="100dp" android:layout_width="match_parent" pt:Imagesrc = "@drawable/ic_launcher" /></LinearLayout>
效果圖
另一個實(shí)例
這里我們來看一個view組合控件的例子：
<string-array name="bao_type"> <item>測試1</item> <item>測試2</item> <item>測試3</item> <item>測試4</item> </string-array>
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@color/gray_common_background" android:orientation="vertical"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <TextView android:id="@+id/txt_viewpage_bar1" style="@style/style_common_pagebar" android:textColor="@color/theme_red" /> <TextView android:id="@+id/txt_viewpage_bar2" style="@style/style_common_pagebar" /> <TextView android:id="@+id/txt_viewpage_bar3" style="@style/style_common_pagebar" /> <TextView android:id="@+id/txt_viewpage_bar4" style="@style/style_common_pagebar" /> </LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <View android:id="@+id/view_viewpage_bar1" style="@style/style_common_pagebar_view" /> <View android:id="@+id/view_viewpage_bar2" style="@style/style_common_pagebar_view" /> <View android:id="@+id/view_viewpage_bar3" style="@style/style_common_pagebar_view" /> <View android:id="@+id/view_viewpage_bar4" style="@style/style_common_pagebar_view" /> </LinearLayout> <android.support.v4.view.ViewPager android:id="@+id/common_viewpage_buttom" android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" /> </LinearLayout>
public interface SlbPageViewOnPageChangeListener { void onPageSelected(int position); void onPageScrollStateChanged(int state); } public class SlbPageViewBar extends LinearLayout { private TextView[] mTotalTxtViews; private View[] mTotalViews; private List<TextView> mTxtViews; private List<View> mViews; private ViewPager mViewPager; private SlbPageViewOnPageChangeListener mSlbPageViewOnPageChangeListener; public SlbPageViewBar(Context context, AttributeSet attrs) { super(context, attrs); mTotalTxtViews = new TextView[4]; mTotalViews = new View[4]; mTxtViews = new ArrayList<>(); mViews = new ArrayList<>(); initView(); } private void initView() { View.inflate(getContext(), R.layout.layout_common_top_pageview_bar, this); mViewPager = (ViewPager) findViewById(R.id.common_viewpage_buttom); mTotalTxtViews[0] = (TextView) findViewById(R.id.txt_viewpage_bar1); mTotalTxtViews[1] = (TextView) findViewById(R.id.txt_viewpage_bar2); mTotalTxtViews[2] = (TextView) findViewById(R.id.txt_viewpage_bar3); mTotalTxtViews[3] = (TextView) findViewById(R.id.txt_viewpage_bar4); mTotalViews[0] = findViewById(R.id.view_viewpage_bar1); mTotalViews[1] = findViewById(R.id.view_viewpage_bar2); mTotalViews[2] = findViewById(R.id.view_viewpage_bar3); mTotalViews[3] = findViewById(R.id.view_viewpage_bar4); } /** * @param title 標(biāo)題名稱數(shù)組 */ public void setTitleView(String[] title) { int legth = title.length > 4 ? 4 : title.length; for (int i = 0; i < legth; i++) { mTotalTxtViews[i].setText(title[i]); mTotalTxtViews[i].setVisibility(View.VISIBLE); mTotalViews[i].setVisibility(View.INVISIBLE); mTotalTxtViews[i].setOnClickListener(new SlbTextViewOnLister(i)); mTxtViews.add(mTotalTxtViews[i]); mViews.add(mTotalViews[i]); } mTotalViews[0].setVisibility(View.VISIBLE); mViewPager.setOnPageChangeListener(mOnButtomPageChangeListener); } public ViewPager getViewPager(){ return mViewPager; } public void setSlbPageViewOnPageChangeListener(SlbPageViewOnPageChangeListener slbPageViewOnPageChangeListener) { this.mSlbPageViewOnPageChangeListener = slbPageViewOnPageChangeListener; } private void changeViewBg(int textViewId, int viewId) { for (View view : mViews) { if (viewId == view.getId()) { view.setVisibility(View.VISIBLE); } else { view.setVisibility(View.INVISIBLE); } } for (TextView view : mTxtViews) { if (textViewId == view.getId()) { view.setTextColor(getResources().getColor(R.color.theme_red)); } else { view.setTextColor(getResources().getColor(R.color.black_normal_text_33333)); } } } class SlbTextViewOnLister implements OnClickListener { private int mItem; public SlbTextViewOnLister(int item) { this.mItem = item; } @Override public void onClick(View v) { mViewPager.setCurrentItem(mItem); } } private ViewPager.OnPageChangeListener mOnButtomPageChangeListener = new ViewPager.OnPageChangeListener() { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override public void onPageSelected(int position) { switch (position) { case 0: changeViewBg(R.id.txt_viewpage_bar1, R.id.view_viewpage_bar1); break; case 1: changeViewBg(R.id.txt_viewpage_bar2, R.id.view_viewpage_bar2); break; case 2: changeViewBg(R.id.txt_viewpage_bar3, R.id.view_viewpage_bar3); break; case 3: changeViewBg(R.id.txt_viewpage_bar4, R.id.view_viewpage_bar4); break; } if (mSlbPageViewOnPageChangeListener != null) mSlbPageViewOnPageChangeListener.onPageSelected(position); } @Override public void onPageScrollStateChanged(int state) { if (mSlbPageViewOnPageChangeListener != null) mSlbPageViewOnPageChangeListener.onPageScrollStateChanged(state); } }; } public class CommonViewpageAdapter extends FragmentPagerAdapter { private List<Fragment> mFragments; private String [] mTitles; public CommonViewpageAdapter(FragmentManager fm, List<Fragment> fragments, String [] titles) { super(fm); mFragments = fragments; mTitles = titles; } @Override public Fragment getItem(int position) { return mFragments.get(position); } @Override public int getCount() { return mFragments.size(); } @Override public CharSequence getPageTitle(int position) { return mTitles[position]; } @Override public void destroyItem(ViewGroup container, int position, Object object) { super.destroyItem(container, position, object); } } <com.slfinance.app.slb.common.ui.view.SlbPageViewBar android:id="@+id/slbpv_buy_huoqibao_SlbPageViewBarshow" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical"/>
private void initButtomPageFragment(SlbPageViewBar slbPageViewBar) { List<Fragment> fragmentList = new ArrayList<>(); Test1Fragment test1Fragment = new Test1Fragment(); Test2Fragment test2Fragment = new Test2Fragment(); Test3Fragment test3Fragment = new Test3Fragment(); Test4Fragment test4Fragment = new Test4Fragment(); fragmentList.add(test1Fragment); fragmentList.add(test2Fragment); fragmentList.add(test3Fragment); fragmentList.add(test4Fragment); String[] titles = getResources().getStringArray(R.array.buy_huoqi_bao_zanquan_detail); slbPageViewBar.setTitleView(titles); CommonViewpageAdapter viewPagerAdapter = new CommonViewpageAdapter( getSupportFragmentManager(), fragmentList, titles); mButtomPageView.setAdapter(viewPagerAdapter); mButtomPageView.setOffscreenPageLimit(3); mButtomPageView.setCurrentItem(0); } 新聞熱點(diǎn)
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