HitTestResult類： WebView中被點選內容的相應資訊，通過WebView的getHitTestResult()獲取！

自定義WebView

/**
 * 自定義WebView，長按圖片獲取圖片url
 * @author LinZhang
 *
 */
public class CustomWebView extends WebView implements OnLongClickListener{
    private Context context;
    private LongClickCallBack mCallBack;
    public CustomWebView
 
(Context context, LongClickCallBack mCallBack) {
        super(context);
        this.context = context;
        this.mCallBack = mCallBack;
        initSettings();
    }

    private void initSettings() {
        // 初始化設定
        WebSettings mSettings = this.getSettings();
        mSettings.setJavaScriptEnabled(true
 
);//開啟javascript
        mSettings.setDomStorageEnabled(true);//開啟DOM
        mSettings.setDefaultTextEncodingName("utf-8");//設定字元編碼
        //設定web頁面
        mSettings.setAllowFileAccess(true);//設定支援檔案流
        mSettings.setSupportZoom(true);// 支援縮放
        mSettings.setBuiltInZoomControls(true);// 支援縮放
        mSettings.setUseWideViewPort(true
 
);// 調整到適合webview大小
        mSettings.setLoadWithOverviewMode(true);// 調整到適合webview大小
        mSettings.setDefaultZoom(ZoomDensity.FAR);// 螢幕自適應網頁,如果沒有這個，在低解析度的手機上顯示可能會異常
        mSettings.setRenderPriority(RenderPriority.HIGH);
        //提高網頁載入速度，暫時阻塞圖片載入，然後網頁載入好了，在進行載入圖片
        mSettings.setBlockNetworkImage(true);
        mSettings.setAppCacheEnabled(true);//開啟快取機制

        setWebViewClient(new MyWebViewClient());
        setOnLongClickListener(this);
    }

    @Override
    public boolean onLongClick(View v) {
        // 長按事件監聽（注意：需要實現LongClickCallBack介面並傳入物件）
        final HitTestResult htr = getHitTestResult();//獲取所點選的內容
        if (htr.getType() == WebView.HitTestResult.IMAGE_TYPE) {//判斷被點選的型別為圖片
            mCallBack.onLongClickCallBack(htr.getExtra());
        }
        return false;
    }

    private class MyWebViewClient extends WebViewClient {
        /**
         * 載入過程中 攔截載入的地址url
         * @param view
         * @param url  被攔截的url
         * @return
         */
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            return super.shouldOverrideUrlLoading(view, url);
        }
        /**
         * 頁面載入過程中，載入資源回撥的方法
         * @param view
         * @param url
         */
        @Override
        public void onLoadResource(WebView view, String url) {
            super.onLoadResource(view, url);
        }
        /**
         * 頁面載入完成回撥的方法
         * @param view
         * @param url
         */
        @Override
        public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);
            // 關閉圖片載入阻塞
            view.getSettings().setBlockNetworkImage(false);

        }
        /**
         * 頁面開始載入呼叫的方法
         * @param view
         * @param url
         * @param favicon
         */
        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            super.onPageStarted(view, url, favicon);
        }

        @Override
        public void onReceivedError(WebView view, int errorCode,
                String description, String failingUrl) {
            super.onReceivedError(view, errorCode, description, failingUrl);
        }

        @Override
        public void onScaleChanged(WebView view, float oldScale, float newScale) {
            super.onScaleChanged(view, oldScale, newScale);
            CustomWebView.this.requestFocus();
            CustomWebView.this.requestFocusFromTouch();
        }

    }

    /**
     * 長按事件回撥介面，傳遞圖片地址
     * @author LinZhang
     */
    public interface LongClickCallBack{
        /**用於傳遞圖片地址*/
        void onLongClickCallBack(String imgUrl);
    }

}

自定義Dialog，用於長按圖片彈出

/**
 * 彈出圖片操作Dialog
 * @author LinZhang
 *
 */
public abstract class CustomDialog extends Dialog {

    private Context context;
    /**
     * 構造器
     * @param context 上下文
     * @param layoutId 資原始檔id
     */
    public CustomDialog(Context context, int layoutId) {
        super(context, R.style.CustomDialog);
        this.context = context;
        createDialog(layoutId);
    }

    /**
     * 設定dialog
     * @param layoutId
     */
    public  void createDialog(int layoutId){
        setContentView(layoutId);
        Window window = getWindow();
        WindowManager.LayoutParams params = window.getAttributes();
        params.width = WindowManager.LayoutParams.WRAP_CONTENT;
        params.height = WindowManager.LayoutParams.WRAP_CONTENT;
        params.gravity = Gravity.CENTER;
        window.setAttributes(params);
        initViews();
        if(!(context instanceof Activity)){
            getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
        }
    }

    public void closeDialog(){
        dismiss();
    }
    /**
     * 用於初始化相應的控制元件
     */
    public abstract void initViews();

}

MainActivity：

public class MainActivity extends Activity implements LongClickCallBack{

    private CustomWebView mCustomWebView;
    private CustomDialog mCustomDialog;
    private ArrayAdapter<String> adapter;
    private boolean isQR;//判斷是否為二維碼
    private Result result;//二維碼解析結果

    @SuppressLint("HandlerLeak")
    private Handler handler = new Handler(){
        public void handleMessage(Message msg) {
            if (msg.what == 0){
                if (isQR){
                     adapter.add("識別圖中二維碼");   
                }
                adapter.notifyDataSetChanged();
            }
        };
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initWebView();
    }

    private void initWebView() {
        // 初始WebView化控制元件
        mCustomWebView = new CustomWebView(this, this);
        mCustomWebView.loadUrl("http://keeganlee.me/post/android/20121206");//載入頁面
        mCustomWebView.setFocusable(true);
        mCustomWebView.setFocusableInTouchMode(true);
        addContentView(mCustomWebView, new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT));
    }

    @Override
    public void onLongClickCallBack(final String imgUrl) {
        // 獲取到圖片地址後做相應的處理
        new Thread(){
            public void run() {
                decodeImage(imgUrl);
                handler.sendEmptyMessage(0);
            };
        }.start();

        showDialog();
    }

    /**
     * 判斷是否為二維碼
     * @param url 圖片地址
     * @return
     */
    private boolean decodeImage(String sUrl){
        result = DecodeImage.handleQRCodeFormBitmap(getBitmap(sUrl));
        if(result == null){
            isQR = false;
        }else {
            isQR = true;
        }
        return isQR;
    }

    /**
     * 根據地址獲取網路圖片
     * @param sUrl 圖片地址
     * @return
     * @throws IOException
     */
    public static Bitmap getBitmap(String sUrl){
        try {
            URL url = new URL(sUrl);
            HttpURLConnection conn = (HttpURLConnection)url.openConnection();
            conn.setConnectTimeout(5000);
            conn.setRequestMethod("GET");
            if(conn.getResponseCode() == 200){
                InputStream inputStream = conn.getInputStream();
                Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
                return bitmap;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
   }

    /**
     * 顯示Dialog
     * @param v
     */
    private void  showDialog() {

        adapter = new ArrayAdapter<String>(this,R.layout.item_dialog);  
        adapter.add("傳送給朋友");  
        adapter.add("儲存到手機");  
        adapter.add("收藏");

        mCustomDialog = new CustomDialog(this, R.layout.custom_dialog) {

            @Override
            public void initViews() {
                // 初始CustomDialog化控制元件
                ListView mListView = (ListView) findViewById(R.id.lv_dialog);
                mListView.setAdapter(adapter); 
                mListView.setOnItemClickListener(new OnItemClickListener() {

                    @Override
                    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                        // 點選事件
                        switch (position) {
                        case 0:
                            Toast.makeText(MainActivity.this, "已傳送給朋友", Toast.LENGTH_LONG).show();
                            closeDialog();
                            break;
                        case 1:
                            Toast.makeText(MainActivity.this, "已儲存到手機", Toast.LENGTH_LONG).show();
                            closeDialog();
                            break;
                        case 2:
                            Toast.makeText(MainActivity.this, "已收藏", Toast.LENGTH_LONG).show();
                            closeDialog();
                            break;
                        case 3:
                            Toast.makeText(MainActivity.this, "二維碼識別結果: " + result.toString(), Toast.LENGTH_LONG).show();       
                            closeDialog();
                            break;
                        }

                    }
                });
            }
        };
        mCustomDialog.show();
    }
}