Android studio webview does not allow cors

Question

我创建了一个android应用程序，我想从我的服务器加载数据，但如果我加载数据，我得到一个"TypeError: Failed to fetch"

我已经尝试了很多方法。我也试着在网页内加载google.com，它也不工作。

我所有的文件:

Main_actifity.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout android:id="@+id/ContentFrame"  
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" 
android:layout_height="match_parent"
/>

MainActivity.java

package com.enervisie.enervisieinspect;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.webkit.WebResourceRequest;
import android.webkit.WebSettings;
import android.webkit.WebViewClient;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.view.View;
import android.webkit.SslErrorHandler;
import android.net.http.SslError;
import android.widget.FrameLayout;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); // Landscape

View decorView = getWindow().getDecorView();
int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_FULLSCREEN;
decorView.setSystemUiVisibility(uiOptions);
// WebView
FrameLayout contentFrame = (FrameLayout) findViewById(R.id.ContentFrame);
WebView mWebView = new WebView(this);
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.getSettings().setAllowFileAccessFromFileURLs(true);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
mWebView.getSettings().setAllowUniversalAccessFromFileURLs(true);
}
mWebView.getSettings().setLoadWithOverviewMode(true);
mWebView.getSettings().setBuiltInZoomControls(false);
mWebView.getSettings().setDatabaseEnabled(true);
mWebView.getSettings().setDomStorageEnabled(true);
mWebView.getSettings().setAllowContentAccess(true);
mWebView.getSettings().setSupportZoom(false);
mWebView.setWebChromeClient(new WebChromeClient());
mWebView.setInitialScale(0);

mWebView.setWebViewClient(new WebViewClient() {
public void onReceivedSslError (WebView view, SslErrorHandler handler, SslError error) {
handler.proceed() ;
}
});
mWebView.setWebViewClient(new WebViewClient() {
@Override
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
view.loadUrl(request.getUrl().toString());
return false;
}
});
mWebView.loadUrl("file:///android_asset/index.html");
contentFrame.removeAllViews();
contentFrame.addView(mWebView);
}
public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); // Landscape
handler.proceed(); // Ignore SSL certificate errors
}
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools">
<application
android:allowBackup="true"
android:dataExtractionRules="@xml/data_extraction_rules"
android:fullBackupContent="@xml/backup_rules"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/Theme.EnervisieInspect"
tools:targetApi="31">
<activity
android:name=".MainActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

我期望从我的web服务器加载数据并将数据发送到我的web服务器。

Answer 1

您应该在Manifest.xml中添加互联网权限

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

和网络安全配置