Android Studio（网页帮助）网：ERR_FILE_NOT_FOUND

Question

Im trying to implement my web app / page inside android studio from my local files, ive followed the official documentation and made an webview button in xml, and declared :

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

in the manifest file. My java activity code is below :

package samples.opencv.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends AppCompatActivity {

    private WebView webview;

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

        webview =(WebView)findViewById(R.id.webview);

        webview.setWebViewClient(new WebViewClient());
        webview.getSettings().setJavaScriptEnabled(true);
        webview.getSettings().setDomStorageEnabled(true);
        webview.setOverScrollMode(WebView.OVER_SCROLL_NEVER);
        webview.loadUrl("file:///C:/Users/olive/OneDrive/Documents/ComputerScience/Project/Atom/index.html");

    }
}

but i get the error on the emulator saying the webpage cannot be loaded as file is not found.

This is my HTML File This is JS file

Answer 1

Put your web resources into the assets folder, usually under <project>/src/main/assets , because emulator cannot see the file under your computer root ".../C:/Users/olive/OneDrive/Documents/ComputerScience/..."

then call:

webView.loadUrl("file:///android_asset/index.html");

Remember that in Android application, files can be read from 3 types of locations:

• Internal storage : Each app has its own, file names are relative to this location. URL takes form file:///myFolder/myFile.html
• External storage : Needs permission and may not always be available. Get the root folder by calling Environment.getExternalStorageDirectory(). So, construct the URL using: String url = "file:///" + Environment.getExternalStorageDirectory().toString() + File.separator + "myFolder/myFile.html"
• Assets : Stored in the apk. Read-only access. URL takes form file:///android_asset/myFolder/myFile.html (See also Loading an Android Resource into a WebView)

Hope it helps.