自定義控制元件之輪播圖的實現
阿新 • • 發佈：2018-12-12
public class BannerView extends RelativeLayout { private boolean startAndclose; private List<String> images = new ArrayList<>(); private Context mcontext; private ViewPager viewpage; private int STARTBANNER = 1; private int bannerTime = 3000; private LinearLayout mPiont; //handler private Handler handler = new Handler() { @Override public void handleMessage(Message msg) { super.handleMessage(msg); if (msg.what == STARTBANNER) { int item = viewpage.getCurrentItem(); item++; viewpage.setCurrentItem(item); } handler.sendEmptyMessageDelayed(STARTBANNER, bannerTime); } }; //內部構造 public BannerView(Context context) { super(context); mcontext = context; init(context); } public BannerView(Context context, AttributeSet attrs) { super(context, attrs); mcontext = context; //自定義屬性 TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.BannerView); //獲取是否開啟輪播的屬性 startAndclose = typedArray.getBoolean(R.styleable.BannerView_startAndclose, false); //獲取輪播秒數的屬性 bannerTime = typedArray.getInteger(R.styleable.BannerView_startTime, 1000); //釋放 typedArray.recycle(); //初始化控制元件 init(context); } public BannerView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); mcontext = context; init(context); } /** * 設定時間 * * @param time */ public void setBannerTime(int time) { bannerTime = time; } //設定iamge圖片的url地址 public void setImageUrl(List<String> picUrls) { images.clear(); images.addAll(picUrls); setAdapter(); } /** * 初始化控制元件設定事件 * * @param context */ private void init(Context context) { View view = View.inflate(context, R.layout.layout_view_bannerviewpage, null); viewpage = view.findViewById(R.id.bannerviewpage); mPiont = view.findViewById(R.id.point); viewpage.addOnPageChangeListener(new ViewPager.OnPageChangeListener() { @Override public void onPageScrolled(int i, float v, int i1) { } @Override public void onPageSelected(int i) { setPoint(i % images.size()); } @Override public void onPageScrollStateChanged(int i) { } }); this.addView(view); } //程式碼方式設定是否輪播 public void setStartAndclose(boolean flage) { if (flage) { handler.sendEmptyMessageDelayed(STARTBANNER, bannerTime); } else { handler.removeMessages(STARTBANNER); } } /** * 設定介面卡 */ private void setAdapter() { MyViewPageAdapter myViewPageAdapter = new MyViewPageAdapter(); viewpage.setAdapter(myViewPageAdapter); myViewPageAdapter.notifyDataSetChanged(); viewpage.setCurrentItem(Integer.MAX_VALUE % 2 - 1); setPoint(0); setStartAndclose(startAndclose); /*viewpage.setCurrentItem(Integer.MAX_VALUE % 2 + 1);*/ } /** * 設定小圓點 */ public void setPoint(int point) { mPiont.removeAllViews(); Log.d("Tag", "" + point); for (int a = 0; a < images.size(); a++) { ImageView imageView = new ImageView(mcontext); if (point == a) { imageView.setBackgroundResource(R.drawable.soild); } else { imageView.setBackgroundResource(R.drawable.unsoild); } mPiont.addView(imageView); ViewGroup.LayoutParams layoutParams = imageView.getLayoutParams(); layoutParams.width = 20; layoutParams.height = 20; imageView.setLayoutParams(layoutParams); } } /** * 定義PagerAdapter */ class MyViewPageAdapter extends PagerAdapter { @Override public int getCount() { return Integer.MAX_VALUE; } @Override public boolean isViewFromObject(@NonNull View view, @NonNull Object o) { return view == o; } @NonNull @Override public Object instantiateItem(@NonNull ViewGroup container, int position) { View view = View.inflate(mcontext, R.layout.layout_view_banneriamge, null); ImageView imageView = view.findViewById(R.id.bannerImage); Picasso.get().load(images.get(position % images.size())).into(imageView); container.addView(view); return view; } @Override public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) { container.removeView((View) object); } } }
自定義屬性的xml
<?xml version="1.0" encoding="utf-8"?> <resources> <declare-styleable name="BannerView"> <attr name="startAndclose" format="boolean"></attr> <attr name="startTime" format="integer"></attr> </declare-styleable> </resources>
使用方法1（通過程式碼進行設定）：
public class MainActivity extends AppCompatActivity {
private List<String> iamges = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
BannerView bannerView = findViewById(R.id.banner);
//初始化資料
iamges.add("http://img.zcool.cn/community/ 使用方法1（通過自定義屬性進行設定）：
<zhoujianfeng.main.bwie.com.view.BannerView
android:id="@+id/banner"
android:layout_width="match_parent"
android:layout_height="200dp"
banner:startAndclose="true"//設定是否開啟輪播
banner:startTime="1000"> //設定輪播時長
</zhoujianfeng.main.bwie.com.view.BannerView>實現效果：
