如何根据按钮单击在新屏幕上的 webview 中打开 url

How to open a url in webview on new screen based on button click

您好,我已经在 Whosebug 中尝试了所有可用的解决方案,但没有任何效果,单击按钮时应用程序停止。请帮帮我。

每当我点击按钮时,应用程序就会崩溃。我希望应用程序在单击按钮时在 Web 视图中打开 url。请帮助我,非常感谢任何帮助。

任何人都可以 post 修改后的代码。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >



<Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_alignParentTop="true"
        android:text="@string/button01" 
        android:onClick="onClick"/>
<Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_alignParentTop="true"
        android:text="@string/button02" 
        android:onClick="onClick"/>


</LinearLayout>   
------------------------------
screen3.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<WebView 
    android:id="@+id/webview" 
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />
</LinearLayout>
-----------------------------------------------------
mainactivity.java

package com.example.webview;



import android.support.v7.app.ActionBarActivity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends ActionBarActivity {


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


    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public void onClick(View v)
    {
        WebView myWebView = (WebView) findViewById(R.id.webview);
        myWebView.setWebViewClient(new WebViewClient());
        WebSettings webSettings = myWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        final Context context = this;
        Intent intent = new Intent(context, SecondActivity.class);
        startActivity(intent);
       switch(v.getId())
       {
           case R.id.button1:
               myWebView.loadUrl("http://techcrunch.com/tag/rss/");
                                break;

          case R.id.button2: 
              myWebView.loadUrl("http://www.bestchance.org.au/");
                               break;

          default:
                               break;
      }


}
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}
--------------------
secondactivity.java
package com.example.webview;

import android.webkit.WebView;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class SecondActivity extends ActionBarActivity {

    private WebView webView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.screen3);




 }


}
-------------------------------

您可能需要 post 您在此处编写代码以查看发生了什么,但是如果您只是想获得一个 webview 弹出窗口,您可以启动浏览器 activity 来加载该页面

String url = "http://www.example.com";
Intent i = new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);

如果你需要它成为你的activity,你需要将一个意图传递给你的新activity并取出url然后你什么时候加载它

webView.loadUrl(URL);

如果问题是崩溃 post 崩溃日志在这里,我们可以看看哪里出了问题

public void onClick(View v)
    {
    WebView myWebView = (WebView) findViewById(R.id.webview);
    myWebView.setWebViewClient(new WebViewClient());
    WebSettings webSettings = myWebView.getSettings();
    webSettings.setJavaScriptEnabled(true);
    final Context context = this;
    Intent intent = new Intent(context, SecondActivity.class);
    String url;

   switch(v.getId())
   {
       case R.id.button1:
           url ="http://techcrunch.com/tag/rss/";
                            break;

      case R.id.button2: 
          url = "http://www.bestchance.org.au/";
                           break;

      default:
                           break;
  }
startActivity(intent);
myWebView.loadUrl(url);
}

只需删除您的代码并将其粘贴到..您试图访问不存在的按钮,因为您启动了一个新的 activity,其中布局发生了变化并且没有调用它们的按钮..

它崩溃的原因是因为您正在调用属于另一个 activity 的 webview。因此,只需将一个字符串从您的 activity 传递到第二个 activity,然后获取该字符串并将其加载到您的 webview。以下是实现它的方法:

在第一个 activity 上,将您的 onClick 方法编辑为:

public void onClick(View v) {
    Intent intent = new Intent(getApplicationContext(), SecondActivity.class);

    switch(v.getId())
    {
        case R.id.action_bar:
            intent.putExtra("url", "http://techcrunch.com/tag/rss/");
            startActivity(intent);
            break;

        case R.id.action_bar_spinner:
            intent.putExtra("url", "http://www.bestchance.org.au/");
            startActivity(intent);
            break;

        default:
            break;
    }
}

然后在您的 SecondActivity 中:

public class SecondActivity extends ActionBarActivity {
    private WebView myWebView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.screen3);

    String url = getIntent().getStringExtra("url");
    myWebView = (WebView) findViewById(R.id.webview);
    myWebView.setWebViewClient(new WebViewClient());
    WebSettings webSettings = myWebView.getSettings();
    webSettings.setJavaScriptEnabled(true);
    myWebView.loadUrl(url);
 }
}
add Internet permission in your Manifest

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

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <WebView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/webview">
    </WebView>
    <androidx.appcompat.widget.AppCompatButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Start"
        android:id="@+id/btn_start"
        android:textSize="20sp"
        android:background="@android:color/darker_gray"
        android:layout_marginTop="250dp"
        android:layout_gravity="center"
        android:textColor="@color/white"
        android:padding="30dp">
    </androidx.appcompat.widget.AppCompatButton>

</LinearLayout>



MainActivity.kt

package com.example.webview

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.webkit.WebViewClient
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        btn_start.setOnClickListener { web_view() }

    }

私人乐趣web_view(){ webview.webViewClient = WebViewClient()

    // this will load the url of the website
    webview.loadUrl("your url")

    // this will enable the javascript settings
    webview.settings.javaScriptEnabled = true

    // if you want to enable zoom feature
    webview.settings.setSupportZoom(true) 
}

    // if you press Back button this code will work
    override fun onBackPressed() {
        // if your webview can go back it will go back
        if (webview.canGoBack())
            webview.goBack()
        // if your webview cannot go back
        // it will exit the application
        else
            super.onBackPressed()
    }
}