Android - 防止 WebView 在 Rotate 上重新加载

android java android-webview

2022-08-31 10:12:28

当我旋转屏幕时，WebView会重新加载整个页面。我不能这样做，因为我的一些内容包含动态/随机材料。当前，当旋转屏幕时，屏幕会从 loadUrl（）方法重新加载原始 URL。

任何想法我的代码有什么问题？

主要活动.java

package com.mark.myapp;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Menu;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends Activity {

    WebView web;
    String webURL = "http://www.google.co.uk/";

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

        if (savedInstanceState != null)
            ((WebView)findViewById(R.id.web)).restoreState(savedInstanceState);

        web = (WebView) findViewById(R.id.web);
        web.getSettings().setJavaScriptEnabled(true);
        web.loadUrl(webURL);
        web.setPadding(0, 0, 0, 0);
        web.getSettings().setLoadWithOverviewMode(true);
        web.getSettings().setUseWideViewPort(true);
        web.getSettings().setSupportZoom(true);
        web.getSettings().setBuiltInZoomControls(true);

        web.setWebViewClient(new HelloWebViewClient());
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    private class HelloWebViewClient extends WebViewClient {
        public boolean shouldOverrideUrlLoading(WebView web, String url) {
            web.loadUrl(url);
            return true;
        }
    }

    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if ((keyCode == KeyEvent.KEYCODE_BACK) && web.canGoBack()) {
            web.goBack();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

}

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.mark.myapp"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"

            android:configChanges="orientation|keyboardHidden">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <uses-permission android:name="android.permission.INTERNET"/>
</manifest>

答案 1

我认为主要问题是你调用web.loadUrl（webURL）;也当保存时 InstanceState ！= null

编辑

尝试：

if (savedInstanceState == null)
{
  web.loadUrl(webURL);
}

EDIT2：您还需要 onSaveInstanceState 和 onRestoreInstanceState 覆盖。

@Override
protected void onSaveInstanceState(Bundle outState )
{
super.onSaveInstanceState(outState);
web.saveState(outState);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState)
{
super.onRestoreInstanceState(savedInstanceState);
web.restoreState(savedInstanceState);
}

注意：也请在您的 AndroidManifest 中添加.xml 在您的 Activity android：configChanges=“orientation|screenSize” 谢谢

答案 2

编辑：找到了更合适的解决方案。

新增功能：

在AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.Example.WebviewSample">
    <application
        <activity android:name=".WebViewActivity"
            <!-- ADD THIS -->
            android:configChanges="orientation|screenSize">
        </activity>
    </application>
</manifest>

在文件中将此添加到方法WebViewActivity.javaonCreate()

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    wView = (WebView) findViewById(R.id.webView);
    if (savedInstanceState == null) {
        wView.loadUrl("https://google.com");
    }
}

同时更新onSaveInstanceState

@Override
protected void onSaveInstanceState(Bundle outState)
{
    super.onSaveInstanceState(outState);
    wView.saveState(outState);
}

和onRestoreInstanceState

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState)
{
    super.onRestoreInstanceState(savedInstanceState);
    wView.restoreState(savedInstanceState);
}

老：

无需 Java 编码。在清单文件中使用它。

 android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"

喜欢：

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="com.Example.WebviewSample.webviewsample"
        android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>        
</application>