问安卓4.4 WebView文件选择器打不开？

EN

    private class MyWebChromeClient extends 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, String acceptType) {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("*/*");
        MainActivity1.this.startActivityForResult(Intent.createChooser(i, "File Browser"), FILECHOOSER_RESULTCODE);
    }

    //For Android 4.1+ only
    protected void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture)
    {
        mUploadMessage = uploadMsg;
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("*/*");
        startActivityForResult(Intent.createChooser(intent, "File Browser"), FILECHOOSER_RESULTCODE);
    }

    protected void openFileChooser(ValueCallback<Uri> uploadMsg)
    {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("*/*");
        startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
    }

    // For Lollipop 5.0+ Devices
    public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams) {
        if (uploadMessage != null) {
            uploadMessage.onReceiveValue(null);
            uploadMessage = null;
        }

        uploadMessage = filePathCallback;
        Intent intent = null;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            intent = fileChooserParams.createIntent();
        }
        try {
            startActivityForResult(intent, REQUEST_SELECT_FILE);
        } catch (ActivityNotFoundException e) {
            uploadMessage = null;
            Toast.makeText(getApplicationContext(), "Cannot Open File Chooser", Toast.LENGTH_LONG).show();
            return false;
        }
        return true;
    }

    @Override
    public boolean onJsAlert(WebView view, String url, String message, JsResult result) {

        Log.d("LogTag", message);
        result.confirm();
        return true;
    }
}

  @Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == REQUEST_SELECT_FILE) {
        if (uploadMessage == null) return;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            uploadMessage.onReceiveValue(WebChromeClient.FileChooserParams.parseResult(resultCode, data));
        }
        uploadMessage = null;
    } else if (requestCode == FILECHOOSER_RESULTCODE) {
        if (null == mUploadMessage)
            return;
        // Use MainActivity.RESULT_OK if you're implementing WebView inside Fragment
        // Use RESULT_OK only if you're implementing WebView inside an Activity
        Uri result = data == null || resultCode != MainActivity.RESULT_OK ? null : data.getData();
        mUploadMessage.onReceiveValue(result);
        mUploadMessage = null;
    }
}