文件浏览无法在android webview中运行

Question

我已经使用androidstudio 2.3.3将网站转换为Android应用程序，无法工作input type="file"选项，当点击input type="file"按钮时没有任何反应。

下面的AndroidManiFest.xml代码

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.webrivers.controlmarketing">
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.WRITE_INTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_INTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_GPS" />
<uses-permission android:name="android.permission.ACCESS_ASSISTED_GPS" />
<uses-permission android:name="android.permission.ACCESS_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:screenOrientation="portrait">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />

        </intent-filter>
    </activity>
    </application>
    </manifest>

下面的MainActivity.java代码

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.app.ProgressDialog;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Build;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.GeolocationPermissions;
public class MainActivity extends ActionBarActivity {
private static final String TAG = MainActivity.class.getSimpleName();
private WebView myWebView;
private WebSettings webSettings;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    myWebView = (WebView) findViewById(R.id.webView);
    webSettings = myWebView.getSettings();
    webSettings.setJavaScriptEnabled(true);
    webSettings.setLoadWithOverviewMode(true);
    webSettings.setAllowFileAccess(true);
    webSettings.setJavaScriptCanOpenWindowsAutomatically(true);
    webSettings.setAppCacheEnabled(true);
    webSettings.setDatabaseEnabled(true);
    webSettings.setDomStorageEnabled(true);
    webSettings.setGeolocationEnabled(true);
    myWebView.setWebViewClient(new Client());
    if (Build.VERSION.SDK_INT >= 19) {
        myWebView.setLayerType(View.LAYER_TYPE_HARDWARE, null);
    }
    else if(Build.VERSION.SDK_INT >=11 && Build.VERSION.SDK_INT < 19) {
        myWebView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
    }        
   myWebView.loadUrl("http://webrivers.co.in/green_medic/lock_screen.html"); 
   }
public boolean onKeyDown(int keyCode, KeyEvent event) {

    if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) {
        myWebView.goBack();
        return true;
    }

    return super.onKeyDown(keyCode, event);
}
public class Client extends WebViewClient {
    ProgressDialog progressDialog;
    public boolean shouldOverrideUrlLoading(WebView view, String url) {

        if (url.contains("mailto:")) {
            view.getContext().startActivity(
                    new Intent(Intent.ACTION_VIEW, Uri.parse(url)));

            return true;
        }else {
            view.loadUrl(url);
            return true;
        }
    }
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
        if (progressDialog == null) {
            progressDialog = new ProgressDialog(MainActivity.this);
            progressDialog.setMessage("Loading...");
            progressDialog.show();
        }
    }
    public void onPageFinished(WebView view, String url) {
        try {
           if (progressDialog.isShowing()) {
                progressDialog.dismiss();
                progressDialog = null;
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
    }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    return false;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {

    int id = item.getItemId();
    return super.onOptionsItemSelected(item);
}
}

有人知道会发生什么吗？