Android WebView 未显示本地 IP 地址

Question

I have a Raspberry Pi running WebIOPi , which is connected to a relay board to turn things on and off via a web-based interface. Here's what the interface looks like in a browser:

Everything works fine, but I want to create an android app that would simply display the web-based interface via WebView. I've used WebView before and it seems pretty straight forward, but I can't get it working.

Here's my code:

MainActivity:

package org.kevinbright.android.backyardcontrolapp;

import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;


public class MainActivity extends Activity {

    private WebView mWebViewer;




@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    //url = getIntent().getStringExtra(EXTRA_URL);

    mWebViewer = (WebView)findViewById(R.id.webviewer);
    mWebViewer.setWebViewClient(new WebViewClient());
    mWebViewer.clearCache(true);
    mWebViewer.getSettings().setJavaScriptEnabled(true);
    mWebViewer.loadUrl("http://192.168.1.100:8000/");
}
}

Here's the XML:

<?xml version="1.0" encoding="UTF-8"?>

<LinearLayout android:orientation="vertical"
              android:layout_height="match_parent"
              android:layout_width="match_parent"
              xmlns:android="http://schemas.android.com/apk/res/android">

<WebView android:layout_height="match_parent"
         android:layout_width="match_parent"
         android:id="@+id/webviewer"/>

And I added:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

to the Manifest.

I don't get any logcat errors, but when I run the app, I get only a white screen. Also, if I substitute " http://www.google.com ", everything works fine. Also, I'm testing on a live device (no emulator). Any suggestions as to why this isn't working?

Answer 1

I have a problem like yours. I've achieved load a local IP, but it takes at least 30 seconds, meanwhile white screen as you. It loooks like chromium (webView) try to find the IP on internet, and at the end said: "oh, it's a local ip, let's load". It's quite weird. I keep on waiting for help as well.

Answer 2

if you're using http protocol, try to add this on your android manifest

android:usesCleartextTraffic="true"

it works for me

Answer 3

public void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.webview);
        mWebView = (WebView)findViewById(R.id.webview);
        mWebView.clearCache(true);
        mWebView.getSettings().setJavaScriptEnabled(true);
        mWebView.loadUrl("http://10.0.2.2:8080/SampleWebServer/Welcome.html");
        //pass complete url 
       
}

Answer 4

May you need to bind your process to specify network?

Look at this solution: https://stackoverflow.com/a/46340497/2808872