本文實(shí)例講述了Android開(kāi)發(fā)實(shí)現(xiàn)的ViewPager引導(dǎo)頁(yè)功能(動(dòng)態(tài)加載指示器)。分享給大家供大家參考，具體如下：
先看效果圖咯~
現(xiàn)在幾乎每個(gè)App都會(huì)有引導(dǎo)頁(yè)，是不是感覺(jué)很炫很厲害，所以就想做出來(lái)一個(gè)學(xué)習(xí)一下~讓自己的App看起來(lái)更加的美觀~
現(xiàn)在來(lái)分析一下：
這個(gè)引導(dǎo)頁(yè)可以分為倆部分~
1.小紅點(diǎn)--來(lái)提醒這是第幾頁(yè)了~
2.“開(kāi)始體驗(yàn)”這個(gè)Button--可以進(jìn)入主界面，但是要控制這個(gè)Button只能在最后一頁(yè)出現(xiàn)
布局的話(huà)使用相對(duì)布局~
那現(xiàn)在來(lái)看看布局吧：
activity_main:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" > <android.support.v4.view.ViewPager android:id="@+id/viewPager" android:layout_width="match_parent" android:layout_height="match_parent" /> <RelativeLayout android:id="@+id/rl" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:layout_marginBottom="20dp"> <LinearLayout android:id="@+id/linear" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal"> </LinearLayout> </RelativeLayout> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/btn" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:layout_marginBottom="50dp" android:visibility="invisible" android:text="開(kāi)始體驗(yàn)"/></RelativeLayout>
開(kāi)始體驗(yàn)這個(gè)Button設(shè)置了不可見(jiàn)來(lái)控制在最后一頁(yè)出現(xiàn)~
小圓點(diǎn)還沒(méi)開(kāi)始寫(xiě)出來(lái)，只是寫(xiě)了個(gè)RelativeLayout嵌套了一個(gè)LinearLayout
然后在分析這個(gè)頁(yè)面的滑動(dòng)~
先把要滑動(dòng)的圖片放進(jìn)來(lái)：
private ViewPager viewPager;private int[]images={R.drawable.guide_1,R.drawable.guide_2,R.drawable.guide_3};private List<ImageView>imageViews;//用來(lái)存放幾個(gè)imageview的實(shí)例實(shí)例化并且加載適配器：
viewPager.setAdapter(new MyAdapter());imageViews=new ArrayList<ImageView>();for(int i=0;i<images.length;i++){ ImageView imageView=new ImageView(this); imageView.setImageResource(images[i]); imageViews.add(imageView);class MyAdapter extends PagerAdapter{ @Override public int getCount() { // TODO Auto-generated method stub return images.length; } @Override public boolean isViewFromObject(View arg0, Object arg1) { // TODO Auto-generated method stub return arg0==arg1; } @Override public Object instantiateItem(ViewGroup container, int position) { // TODO Auto-generated method stub container.addView(imageViews.get(position)); return imageViews.get(position); } @Override public void destroyItem(ViewGroup container, int position, Object object) { // TODO Auto-generated method stub container.removeView((View)object); }}其實(shí)寫(xiě)到這里就可以完成圖片的滑動(dòng)，但是還沒(méi)有小紅點(diǎn)的出現(xiàn)~這時(shí)候就要寫(xiě)小紅點(diǎn)了~小紅點(diǎn)默認(rèn)是在第一頁(yè)就出現(xiàn)了的~
在drawable文件下寫(xiě)了倆個(gè)xml文件，red_circle--代表紅點(diǎn)，gray_circle--代表灰點(diǎn)~
red_circle:
<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <size android:width="10dp" android:height="10dp"/> <!-- 填充顏色 --> <solid android:color="#ff0000"/></shape>
gray_circle:
<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <size android:width="10dp" android:height="10dp"/> <!-- 填充顏色 --> <solid android:color="#ECECEC"/></shape>
現(xiàn)在代表顏色的文件寫(xiě)好了，那怎么把它們加進(jìn)去呢~~
先默認(rèn)都是灰點(diǎn)，然后在把紅點(diǎn)覆蓋上去，看代碼怎么寫(xiě)：
ImageView gray_Iv=new ImageView(this);gray_Iv.setImageResource(R.drawable.gray_circle);//使用LayoutParams改變控件的位置LinearLayout.LayoutParams layoutParams=new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);if(i>0){ layoutParams.leftMargin=20;}gray_Iv.setLayoutParams(layoutParams);li.addView(gray_Iv);把灰點(diǎn)都加到LinearLayout里面
而紅點(diǎn)：
red_Iv=new ImageView(this);red_Iv.setImageResource(R.drawable.red_circle);rl.addView(red_Iv);
把紅點(diǎn)加到RelativeLayout里面
還要寫(xiě)個(gè)示圖樹(shù)~讓紅點(diǎn)來(lái)滑動(dòng)：
//示圖樹(shù)red_Iv.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() { //該方法就是在界面全面繪制結(jié)束之后回調(diào) @Override public void onGlobalLayout() { // TODO Auto-generated method stub //求距離 left=li.getChildAt(1).getLeft()-li.getChildAt(0).getLeft(); System.out.println("left為"+left); red_Iv.getViewTreeObserver().removeOnGlobalLayoutListener(this); }});viewPager的滑動(dòng)監(jiān)聽(tīng)器還要監(jiān)聽(tīng)圖片什么時(shí)候滑動(dòng)，以至于讓紅點(diǎn)滑動(dòng)的跟好看（就比如第一個(gè)點(diǎn)到第二個(gè)點(diǎn)的途中也會(huì)有紅點(diǎn)）//滑動(dòng)的時(shí)候@Overridepublic void onPageScrolled(int position, float posionOffset, int arg2) { // TODO Auto-generated method stub System.out.println(posionOffset);//滑動(dòng)的百分比 RelativeLayout.LayoutParams layoutParams= (RelativeLayout.LayoutParams)red_Iv.getLayoutParams(); layoutParams.leftMargin=(int)(left*posionOffset+position*left); red_Iv.setLayoutParams(layoutParams);}還要分析下讓“開(kāi)始體驗(yàn)”這個(gè)Button出現(xiàn)在最后一頁(yè)，那就只能在viewPager的滑動(dòng)監(jiān)聽(tīng)方法里面寫(xiě)可見(jiàn)與不可見(jiàn)了~
@Overridepublic void onPageSelected(int position) { // TODO Auto-generated method stub if(position==images.length-1){ btn.setVisibility(View.VISIBLE); }else{ btn.setVisibility(View.GONE); }}完整MainActicity代碼：
public class MainActivity extends Activity { private ViewPager viewPager; private int[]images={R.drawable.guide_1,R.drawable.guide_2,R.drawable.guide_3}; private List<ImageView>imageViews;//用來(lái)存放幾個(gè)imageview的實(shí)例 private LinearLayout li; private RelativeLayout rl; private ImageView red_Iv; private int left; private Button btn; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.activity_main); viewPager=(ViewPager) findViewById(R.id.viewPager); li=(LinearLayout) findViewById(R.id.linear); rl=(RelativeLayout) findViewById(R.id.rl); btn=(Button) findViewById(R.id.btn); viewPager.setAdapter(new MyAdapter()); imageViews=new ArrayList<ImageView>(); for(int i=0;i<images.length;i++){ ImageView imageView=new ImageView(this); imageView.setImageResource(images[i]); imageViews.add(imageView); ImageView gray_Iv=new ImageView(this); gray_Iv.setImageResource(R.drawable.gray_circle); //使用LayoutParams改變控件的位置 LinearLayout.LayoutParams layoutParams= new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); if(i>0){ layoutParams.leftMargin=20; } gray_Iv.setLayoutParams(layoutParams); li.addView(gray_Iv); } red_Iv=new ImageView(this); red_Iv.setImageResource(R.drawable.red_circle); rl.addView(red_Iv); //示圖樹(shù) red_Iv.getViewTreeObserver(). addOnGlobalLayoutListener(new OnGlobalLayoutListener() { //該方法就是在界面全面繪制結(jié)束之后回調(diào) @Override public void onGlobalLayout() { // TODO Auto-generated method stub //求距離 left=li.getChildAt(1).getLeft()-li.getChildAt(0).getLeft(); System.out.println("left為"+left); red_Iv.getViewTreeObserver().removeOnGlobalLayoutListener(this); } }); viewPager.setOnPageChangeListener(new OnPageChangeListener() { @Override public void onPageSelected(int position) { // TODO Auto-generated method stub if(position==images.length-1){ btn.setVisibility(View.VISIBLE); }else{ btn.setVisibility(View.GONE); } } //滑動(dòng)的時(shí)候 @Override public void onPageScrolled(int position, float posionOffset, int arg2) { // TODO Auto-generated method stub System.out.println(posionOffset);//滑動(dòng)的百分比 RelativeLayout.LayoutParams layoutParams= (RelativeLayout.LayoutParams)red_Iv.getLayoutParams(); layoutParams.leftMargin=(int)(left*posionOffset+position*left); red_Iv.setLayoutParams(layoutParams); } @Override public void onPageScrollStateChanged(int arg0) { // TODO Auto-generated method stub } }); } class MyAdapter extends PagerAdapter{ @Override public int getCount() { // TODO Auto-generated method stub return images.length; } @Override public boolean isViewFromObject(View arg0, Object arg1) { // TODO Auto-generated method stub return arg0==arg1; } @Override public Object instantiateItem(ViewGroup container, int position) { // TODO Auto-generated method stub container.addView(imageViews.get(position)); return imageViews.get(position); } @Override public void destroyItem(ViewGroup container, int position, Object object) { // TODO Auto-generated method stub container.removeView((View)object); } }} PS：這里使用到了android-support-v4.jar文件，需要在項(xiàng)目中導(dǎo)入jar包，可參考本站相關(guān)教程//m.survivalescaperooms.com/softjc/552873.html
附：完整實(shí)例代碼點(diǎn)擊此處本站下載。
更多關(guān)于Android相關(guān)內(nèi)容感興趣的讀者可查看本站專(zhuān)題：《Android開(kāi)發(fā)入門(mén)與進(jìn)階教程》、《Android布局layout技巧總結(jié)》、《Android視圖View技巧總結(jié)》、《Android編程之a(chǎn)ctivity操作技巧總結(jié)》、《Android操作json格式數(shù)據(jù)技巧總結(jié)》、《Android資源操作技巧匯總》及《Android控件用法總結(jié)》
希望本文所述對(duì)大家Android程序設(shè)計(jì)有所幫助。
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