Android应用中WebView无法使用H5inputtype="file"如何解决

private ValueCallback mUploadMessage;
public ValueCallback uploadMessage;
public static final int REQUEST_SELECT_FILE = 100;
private final static int FILECHOOSER_RESULTCODE = 2;
webview.setWebChromeClient(new WebChromeClient(){
    // For 3.0+ Devices (Start)
    // onActivityResult attached before constructor
    protected void openFileChooser(ValueCallback uploadMsg, String acceptType)
    {
      mUploadMessage = uploadMsg;
      Intent i = new Intent(Intent.ACTION_GET_CONTENT);
      i.addCategory(Intent.CATEGORY_OPENABLE);
      i.setType("image/*");
      startActivityForResult(Intent.createChooser(i, "File Browser"), FILECHOOSER_RESULTCODE);
    }
    // For Lollipop 5.0+ Devices
    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public boolean onShowFileChooser(WebView mWebView, ValueCallback filePathCallback, WebChromeClient.FileChooserParams fileChooserParams)
    {
      if (uploadMessage != null) {
        uploadMessage.onReceiveValue(null);
        uploadMessage = null;
      }
      uploadMessage = filePathCallback;
      Intent intent = fileChooserParams.createIntent();
      try
      {
        startActivityForResult(intent, REQUEST_SELECT_FILE);
      } catch (ActivityNotFoundException e)
      {
        uploadMessage = null;
        Toast.makeText(getBaseContext(), "Cannot Open File Chooser", Toast.LENGTH_LONG).show();
        return false;
      }
      return true;
    }
    //For Android 4.1 only
    protected void openFileChooser(ValueCallback uploadMsg, String acceptType, String capture)
    {
      mUploadMessage = uploadMsg;
      Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
      intent.addCategory(Intent.CATEGORY_OPENABLE);
      intent.setType("image/*");
      startActivityForResult(Intent.createChooser(intent, "File Browser"), FILECHOOSER_RESULTCODE);
    }
    protected 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"), FILECHOOSER_RESULTCODE);
    }
  });
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent)
{
  if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
  {
    if (requestCode == REQUEST_SELECT_FILE)
    {
      if (uploadMessage == null)
        return;
      uploadMessage.onReceiveValue(WebChromeClient.FileChooserParams.parseResult(resultCode, intent));
      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 = intent == null || resultCode != MainActivity.RESULT_OK ? null : intent.getData();
    mUploadMessage.onReceiveValue(result);
    mUploadMessage = null;
  }
  else
    Toast.makeText(getBaseContext(), "Failed to Upload Image", Toast.LENGTH_LONG).show();
}