Android WebView 文件上传

Android WebView 文件上传

1. Android 浏览器实现文件上传，默认在 App 中嵌套 WebView 是不支持文件上传的，需要自己重写WebChromeClient 里面的文件上传方法，相应的针对 Android 不同的版本，文件上传的方法又各不相同。
2. 今总结如下：见代码主要是：自定义了WebChromeClient

public class MainFragment extends Fragment {

    private static final String TAG = MainFragment.class.getSimpleName();

    public static final int REQUEST_CODE_LOLIPOP = 1;
    private final static int RESULT_CODE_ICE_CREAM = 2;

    private WebView mWebView;
    private ValueCallback mFilePathCallback;
    private String mCameraPhotoPath;

    private ValueCallback mUploadMessage;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);

        // Get reference of WebView from layout/activity_main.xml
        mWebView = (WebView) rootView.findViewById(R.id.fragment_main_webview);

        setUpWebViewDefaults(mWebView);

        // Check whether we're recreating a previously destroyed instance
        if (savedInstanceState != null) {
            // Restore the previous URL and history stack
            mWebView.restoreState(savedInstanceState);
        }

        mWebView.setWebChromeClient(new WebChromeClient() {

            //The undocumented magic method override
            //Eclipse will swear at you if you try to put @Override here
            // For Android 3.0+
            public void openFileChooser(ValueCallback uploadMsg) {

                mUploadMessage = uploadMsg;
                Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                i.addCategory(Intent.CATEGORY_OPENABLE);
                i.setType("image/*");
                startActivityForResult(Intent.createChooser(i, "File Chooser"),
                        RESULT_CODE_ICE_CREAM);

            }

            // For Android 3.0+
            public void openFileChooser(ValueCallback uploadMsg, String acceptType) {
                mUploadMessage = uploadMsg;
                Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                i.addCategory(Intent.CATEGORY_OPENABLE);
                i.setType("*/*");
                startActivityForResult(Intent.createChooser(i, "File Browser"),
                        RESULT_CODE_ICE_CREAM);
            }

            //For Android 4.1
            public void openFileChooser(ValueCallback uploadMsg, String acceptType, String capture) {
                mUploadMessage = uploadMsg;
                Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                i.addCategory(Intent.CATEGORY_OPENABLE);
                i.setType("image/*");
                startActivityForResult(Intent.createChooser(i, "File Chooser"),
                        RESULT_CODE_ICE_CREAM);

            }

            //For Android5.0+
            public boolean onShowFileChooser(
                    WebView webView, ValueCallback filePathCallback,
                    FileChooserParams fileChooserParams) {
                    //这句话建议屏蔽掉，当多次打开上传时会导致崩溃  但这是 google 官方做法
                if (mFilePathCallback != null) {
                    mFilePathCallback.onReceiveValue(null);
                }
                mFilePathCallback = filePathCallback;

                Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                if (takePictureIntent.resolveActivity(getActivity().getPackageManager()) != null) {
                    // Create the File where the photo should go
                    File photoFile = null;
                    try {
                        photoFile = createImageFile();
                        takePictureIntent.putExtra("PhotoPath", mCameraPhotoPath);
                    } catch (IOException ex) {
                        // Error occurred while creating the File
                        Log.e(TAG, "Unable to create Image File", ex);
                    }

                    // Continue only if the File was successfully created
                    if (photoFile != null) {
                        mCameraPhotoPath = "file:" + photoFile.getAbsolutePath();
                        takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,
                                Uri.fromFile(photoFile));
                    } else {
                        takePictureIntent = null;
                    }
                }

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

                Intent[] intentArray;
                if (takePictureIntent != null) {
                    intentArray = new Intent[]{takePictureIntent};
                } else {
                    intentArray = new Intent[0];
                }

                Intent chooserIntent = new Intent(Intent.ACTION_CHOOSER);
                chooserIntent.putExtra(Intent.EXTRA_INTENT, contentSelectionIntent);
                chooserIntent.putExtra(Intent.EXTRA_TITLE, "Image Chooser");
                chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentArray);

                startActivityForResult(chooserIntent, REQUEST_CODE_LOLIPOP);

                return true;
            }
        });

        // Load the local index.html file
        if (mWebView.getUrl() == null) {
            //mWebView.loadUrl("file:///android_asset/www/index.html");
            //mWebView.loadUrl("https://www.script-tutorials.com/demos/199/index.html");
            mWebView.loadUrl("http://192.168.1.109:8080/AndroidMvvmServer/upload");
        }

        return rootView;
    }

    /**
     * More info this method can be found at
     * http://developer.android.com/training/camera/photobasics.html
     *
     * @return
     * @throws IOException
     */
    private File createImageFile() throws IOException {
        // Create an image file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        String imageFileName = "JPEG_" + timeStamp + "_";
        File storageDir = Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_PICTURES);
        File imageFile = File.createTempFile(
                imageFileName,  /* prefix */
                ".jpg",         /* suffix */
                storageDir      /* directory */
        );
        return imageFile;
    }

    /**
     * Convenience method to set some generic defaults for a
     * given WebView
     *
     * @param webView
     */
    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    private void setUpWebViewDefaults(WebView webView) {
        WebSettings settings = webView.getSettings();

        // Enable Javascript
        settings.setJavaScriptEnabled(true);

        // Use WideViewport and Zoom out if there is no viewport defined
        settings.setUseWideViewPort(true);
        settings.setLoadWithOverviewMode(true);

        // Enable pinch to zoom without the zoom buttons
        settings.setBuiltInZoomControls(true);

        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.HONEYCOMB) {
            // Hide the zoom controls for HONEYCOMB+
            settings.setDisplayZoomControls(false);
        }

        // Enable remote debugging via chrome://inspect
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            WebView.setWebContentsDebuggingEnabled(true);
        }

        // We set the WebViewClient to ensure links are consumed by the WebView rather
        // than passed to a browser if it can
        mWebView.setWebViewClient(new WebViewClient());
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        switch (requestCode) {
            case RESULT_CODE_ICE_CREAM:
                Uri uri = null;
                if (data != null) {
                    uri = data.getData();
                }
                mUploadMessage.onReceiveValue(uri);
                mUploadMessage = null;
                break;
            case REQUEST_CODE_LOLIPOP:
                Uri[] results = null;
                // Check that the response is a good one
                if (resultCode == Activity.RESULT_OK) {
                    if (data == null) {
                        // If there is not data, then we may have taken a photo
                        if (mCameraPhotoPath != null) {
                            results = new Uri[]{Uri.parse(mCameraPhotoPath)};
                        }
                    } else {
                        String dataString = data.getDataString();
                        if (dataString != null) {
                            results = new Uri[]{Uri.parse(dataString)};
                        }
                    }
                }

                mFilePathCallback.onReceiveValue(results);
                mFilePathCallback = null;
                break;
        }
    }
    }