Webview之H5頁面調用android的圖庫及文件管理

• h5頁面打開圖片管理器

通常頁面在pc打開文件管理器是用 type=」file」的代碼，但是這在android的webview是無效的，必須爲webview設定WebChromeClient代碼以下：

1. mWebview.setWebChromeClient(((HomeActivity) mContext).mOpenFileWebChromeClient);
2. OpenFileWebChromeClient類中重寫並添加onShowFileChooser、openFileChooser：這樣纔會打開文件管理器，可是還須要把選擇的地址穿回到頁面，具體看3.

public class OpenFileWebChromeClient extends WebChromeClient {
    public static final int REQUEST_FILE_PICKER = 1;
    public ValueCallback<Uri> mFilePathCallback;
    public ValueCallback<Uri[]> mFilePathCallbacks;
    Activity mContext;
    public OpenFileWebChromeClient(Activity mContext){
        super();
        this.mContext = mContext;
    }
    // Android < 3.0 調用這個方法 
    public void openFileChooser(ValueCallback<Uri> filePathCallback) {
        mFilePathCallback = filePathCallback;
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("*/*");
        mContext.startActivityForResult(Intent.createChooser(intent, "File Chooser"),
                REQUEST_FILE_PICKER);
    }
     // 3.0 + 調用這個方法 
    public void openFileChooser(ValueCallback filePathCallback,
            String acceptType) {
        mFilePathCallback = filePathCallback;
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("*/*");
        mContext.startActivityForResult(Intent.createChooser(intent, "File Chooser"),
                REQUEST_FILE_PICKER);
    }
// / js上傳文件的<input type="file" name="fileField" id="fileField" />事件捕獲 
            // Android > 4.1.1 調用這個方法 
    public void openFileChooser(ValueCallback<Uri> filePathCallback,
            String acceptType, String capture) {
        mFilePathCallback = filePathCallback;
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("*/*");
        mContext.startActivityForResult(Intent.createChooser(intent, "File Chooser"),
                REQUEST_FILE_PICKER);
    }

    @Override
    public boolean onShowFileChooser(WebView webView,
            ValueCallback<Uri[]> filePathCallback,
            WebChromeClient.FileChooserParams fileChooserParams) {
        mFilePathCallbacks = filePathCallback;
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("*/*");
        mContext.startActivityForResult(Intent.createChooser(intent, "File Chooser"),
                REQUEST_FILE_PICKER);
        return true;
    }
}

3.地址回傳至頁面：
在2中提到了.startActivityForResult(Intent.createChooser(intent, "File Chooser")，這個裏面會回調activity的onActivityResult方法，因此在所在的activity中添加以下代碼：


/** * 如下是webview的照片上傳時候，用於在網頁打開android圖庫文件 */
    public OpenFileWebChromeClient mOpenFileWebChromeClient = new OpenFileWebChromeClient(
            this);

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent intent) {
        if (requestCode == OpenFileWebChromeClient.REQUEST_FILE_PICKER) {
            if (mOpenFileWebChromeClient.mFilePathCallback != null) {
                Uri result = intent == null || resultCode != Activity.RESULT_OK ? null
                        : intent.getData();
                if (result != null) {
                    String path = MediaUtility.getPath(getApplicationContext(),
                            result);
                    Uri uri = Uri.fromFile(new File(path));
                    mOpenFileWebChromeClient.mFilePathCallback
                            .onReceiveValue(uri);
                } else {
                    mOpenFileWebChromeClient.mFilePathCallback
                            .onReceiveValue(null);
                }
            }
            if (mOpenFileWebChromeClient.mFilePathCallbacks != null) {
                Uri result = intent == null || resultCode != Activity.RESULT_OK ? null
                        : intent.getData();
                if (result != null) {
                    String path = MediaUtility.getPath(getApplicationContext(),
                            result);
                    Uri uri = Uri.fromFile(new File(path));
                    mOpenFileWebChromeClient.mFilePathCallbacks
                            .onReceiveValue(new Uri[] { uri });
                } else {
                    mOpenFileWebChromeClient.mFilePathCallbacks
                            .onReceiveValue(null);
                }
            }

            mOpenFileWebChromeClient.mFilePathCallback = null;
            mOpenFileWebChromeClient.mFilePathCallbacks = null;
        }
    }

public class MediaUtility {
    /** * Get a file path from a Uri. This will get the the path for Storage Access * Framework Documents, as well as the _data field for the MediaStore and * other file-based ContentProviders. * * @param context The context. * @param uri The Uri to query. * @author paulburke */
    @TargetApi(Build.VERSION_CODES.KITKAT)
    public static String getPath(final Context context, final Uri uri) {
        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

        // DocumentProvider
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }

                // TODO handle non-primary volumes
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {

                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }

                final String selection = "_id=?";
                final String[] selectionArgs = new String[]{split[1]};

                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        }
        // MediaStore (and general)
        else if ("content".equalsIgnoreCase(uri.getScheme())) {
            return getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }

        return null;
    }


    /** * Get the value of the data column for this Uri. This is useful for * MediaStore Uris, and other file-based ContentProviders. * * @param context The context. * @param uri The Uri to query. * @param selection (Optional) Filter used in the query. * @param selectionArgs (Optional) Selection arguments used in the query. * @return The value of the _data column, which is typically a file path. */
    public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
        Cursor cursor = null;
        final String column = "_data";
        final String[] projection = {column};

        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
            if (cursor != null && cursor.moveToFirst()) {
                final int column_index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(column_index);
            }
        } finally {
            if (cursor != null) cursor.close();
        }
        return null;
    }


    /** * @param uri The Uri to check. * @return Whether the Uri authority is ExternalStorageProvider. */
    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }


    /** * @param uri The Uri to check. * @return Whether the Uri authority is DownloadsProvider. */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }


    /** * @param uri The Uri to check. * @return Whether the Uri authority is MediaProvider. */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }
}