Android点击WebView实现图片缩放及滑动浏览效果

webView = (WebView) findViewById(R.id.webview);  webView.loadUrl(url);  WebSettings settings = webView.getSettings();  //设置屏幕适应  settings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.NARROW_COLUMNS);  settings.setUseWideViewPort(true);  settings.setLoadWithOverviewMode(true);  //防止中文乱码  settings.setDefaultTextEncodingName("UTF -8");  settings.setJavaScriptEnabled(true);  //载入js  webView.addJavascriptInterface(new JavascriptInterface(this), "imagelistner");  webView.setWebViewClient(new WebViewClient() {   // 网页跳转   @Override   public boolean shouldOverrideUrlLoading(WebView view, String url) {    view.loadUrl(url);    return super.shouldOverrideUrlLoading(view, url);   }   // 网页加载结束   @Override   public void onPageFinished(WebView view, String url) {    super.onPageFinished(view, url);    // html加载完成之后，添加监听图片的点击js函数    addImageClickListner();   }  });

 // 注入js函数监听 private void addImageClickListner() {  //遍历页面中所有img的节点，因为节点里面的图片的url即objs[i].src，保存所有图片的src.  //为每个图片设置点击事件，objs[i].onclick  webView.loadUrl("javascript:(function(){" +    "var objs = document.getElementsByTagName(/"img/"); " +    "for(var i=0;i<objs.length;i++) " +    "{" +    "window.imagelistner.readImageUrl(objs[i].src); " +    " objs[i].onclick=function() " +    " { " +    " window.imagelistner.openImage(this.src); " +    " } " +    "}" +    "})()"); } // js通信接口 public class JavascriptInterface {  private Context context;  public JavascriptInterface(Context context) {   this.context = context;  }  @android.webkit.JavascriptInterface  public void readImageUrl(String img) {  //把所有图片的url保存在ArrayList<String>中   images.add(img);  }  @android.webkit.JavascriptInterface //对于targetSdkVersion>=17的，要加这个声明  public void openImage(String clickimg)//点击图片所调用到的函数  {   int index = 0;   ArrayList<String> list = addImages();   for (String url : list)    if (url.equals(clickimg)) index = list.indexOf(clickimg);//获取点击图片在整个页面图片中的位置   Intent intent = new Intent();   Bundle bundle = new Bundle();   bundle.putStringArrayList("list_image", list);   bundle.putInt("index", index);   intent.putExtra("bundle", bundle);//将所有图片的url以及点击图片的位置作为参数传给启动的activity   intent.setClass(context, ShowWebImageActivity.class);   context.startActivity(intent);//启动ViewPagerActivity,用于显示图片  } } //去重复 private ArrayList<String> addImages() {  ArrayList<String> list = new ArrayList<>();  Set set = new HashSet();  for (String cd:images) {   if(set.add(cd)){    list.add(cd);   }  }  return list; }

public class ShowWebImageActivity extends AppCompatActivity{ private ArrayList<String> images; @Override protected void onCreate(@Nullable Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_show_webimage);  HackyViewPager hackyViewPager = (HackyViewPager) findViewById(R.id.view_pager);  Bundle bundle = getIntent().getBundleExtra("bundle");  images = bundle.getStringArrayList("list_image");  int index = bundle.getInt("index");  hackyViewPager.setAdapter(new ViewPagerAdapter());  hackyViewPager.setCurrentItem(index); } class ViewPagerAdapter extends PagerAdapter{  @Override  public int getCount() {   return images.size();  }  @Override  public boolean isViewFromObject(View view, Object object) {   return view == object;  }  @Override  public Object instantiateItem(ViewGroup container, int position) {   View view = View.inflate(ShowWebImageActivity.this,R.layout.view_pager_item,null);   PhotoView photoView = (PhotoView) view.findViewById(R.id.photoview);   TextView indicator = (TextView) view.findViewById(R.id.indicator);   //用Glide加载图片   Glide.with(ShowWebImageActivity.this).load(images.get(position)).into(photoView);   CharSequence text = getString(R.string.viewpager_indicator, position+1, images.size());   //设置indicator   indicator.setText(text);   container.addView(view, ViewPager.LayoutParams.MATCH_PARENT, ViewPager.LayoutParams.MATCH_PARENT);   return view;  }  @Override  public void destroyItem(ViewGroup container, int position, Object object) {   container.removeView((View) object);  } }}

public class HackyViewPager extends ViewPager { private boolean isLocked; public HackyViewPager(Context context) {  super(context);  isLocked = false; } public HackyViewPager(Context context, AttributeSet attrs) {  super(context, attrs);  isLocked = false; } @Override public boolean onInterceptTouchEvent(MotionEvent ev) {//用于处理Touch事件  if (!isLocked) {   try {    return super.onInterceptTouchEvent(ev);   } catch (IllegalArgumentException e) {    e.printStackTrace();    return false;   }  }  return false; } @Override public boolean onTouchEvent(MotionEvent event) {  return !isLocked && super.onTouchEvent(event); }}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" > <uk.co.senab.photoview.PhotoView  android:id="@+id/photoview"  android:layout_width="match_parent"  android:layout_height="match_parent" /> <TextView  android:id="@+id/indicator"  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:layout_alignParentBottom="true"  android:gravity="center"  android:textSize="18sp"  android:textColor="@android:color/black"  android:text="@string/viewpager_indicator"  android:background="@android:color/transparent" /></RelativeLayout>

<string name="viewpager_indicator">%1$d/%2$d</string>