在手機端使用chrome開啟imgur，上傳圖片會有從相機與從圖片庫兩個選項。
在WebView內，從圖片庫上傳沒問題，但相機拍照後無法將圖片上傳。

發現問題是在onActivityResult的intent使用相機拍照後為{}，從圖片庫則正常所導致。但這是結果不是原因。startActivityForResult也沒有異常。感覺要override Activity.java或Looper.java內的東西，但沒有頭緒。

MainActivity

public class MainActivity extends Activity {

    private WebView webview;
    private ValueCallback<Uri> mUploadMessage;
    private ValueCallback<Uri[]> mUploadMessages;
    private Uri mCapturedImageURI = null;
    private static final int MY_CAMERA_REQUEST_CODE = 100;
    private static final int FILECHOOSER_RESULTCODE = 1;

    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        webview =(WebView)findViewById(R.id.webView);

        webview.setOverScrollMode(WebView.OVER_SCROLL_NEVER);
        webview.loadUrl("https://imgur.com/upload");
        CookieManager cookieManager = CookieManager.getInstance();
        cookieManager.setAcceptThirdPartyCookies(webview,true);


        webview.setWebViewClient(new WebViewClient());

        WebSettings webSettings = webview.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setDomStorageEnabled(true);
        webview.getSettings().setJavaScriptEnabled(true);
        webview.getSettings().setDomStorageEnabled(true);
        webview.getSettings().setAppCacheEnabled(false);
        webview.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
        webview.getSettings().setUseWideViewPort(true);
        webview.getSettings().setLoadWithOverviewMode(true);
        webview.getSettings().setBuiltInZoomControls(false);
        webview.getSettings().setSupportZoom(false);
        webview.getSettings().setDomStorageEnabled(true);
        webview.getSettings().setDatabaseEnabled(true);

        webview.setWebChromeClient(new WebChromeClient() {

            // For api level bellow 24
            public boolean shouldOverrideUrlLoading(WebView view, String url) {

                if (url.startsWith("http")) {
                    return false;
                }

                return false;
            }


            // From api level 24
            @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
            public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
                String url = request.getUrl().toString();

                if (url.startsWith("http")) {
                    return false;
                }

                return false;
            }

            public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams) {
                mUploadMessages = filePathCallback;
                openImageChooser();
                return true;
            }

        });
    }

    private void openImageChooser() {
        try {
            File imageStorageDir = new File(Environment.getDataDirectory(), "wbn");

            if (!imageStorageDir.exists()) {
                imageStorageDir.mkdirs();
            }
            File file = new File(imageStorageDir + File.separator + "IMG_" + String.valueOf(System.currentTimeMillis()) + ".jpg");
            mCapturedImageURI = Uri.fromFile(file);

            final Intent captureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, mCapturedImageURI);

            Intent i = new Intent(Intent.ACTION_GET_CONTENT);
            i.addCategory(Intent.CATEGORY_OPENABLE);
            i.setType("image/*");

            Intent chooserIntent = Intent.createChooser(i, "Image Chooser");
            chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Parcelable[]{captureIntent});

            startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
        super.onActivityResult(requestCode, resultCode, intent);

        if (requestCode == FILECHOOSER_RESULTCODE) {

            if (null == this.mUploadMessage && null == this.mUploadMessages) {
                return;
            }

            if (null != mUploadMessage) {
                handleUploadMessage(requestCode, resultCode, intent);

            } else if (mUploadMessages != null) {
                handleUploadMessages(requestCode, resultCode, intent);
            }
        }
    }

    private void handleUploadMessage(int requestCode, int resultCode, Intent intent) {
        Uri result = null;
        try {
            if (resultCode != RESULT_OK) {
                result = null;
            } else {
                result = intent == null ? mCapturedImageURI : intent.getData();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        mUploadMessage.onReceiveValue(result);
        mUploadMessage = null;
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    private void handleUploadMessages(int requestCode, int resultCode, Intent intent) {
        Uri[] results = null;
        try {
            if (resultCode != RESULT_OK) {
                results = null;
            } else {
                if (intent != null) {
                    String dataString = intent.getDataString();
                    ClipData clipData = intent.getClipData();
                    if (clipData != null) {
                        results = new Uri[clipData.getItemCount()];
                        for (int i = 0; i < clipData.getItemCount(); i++) {
                            ClipData.Item item = clipData.getItemAt(i);
                            results[i] = item.getUri();
                        }
                    }
                    if (dataString != null) {
                        results = new Uri[]{Uri.parse(dataString)};
                    }
                } else {
                    results = new Uri[]{mCapturedImageURI};
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        mUploadMessages.onReceiveValue(results);
        mUploadMessages = null;
    }

manifest內新增權限

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.camera" android:required="true" />
    <uses-feature android:name="android.hardware.camera.front" android:required="true" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_INTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_INTERNAL_STORAGE" />

activity_main就拉了一個webView而已

註1:該開的權限有開

註2:不是真的要傳上imgur，只是方便測試