谁能帮助我的第一个 WebView 我被这个问题困住了？不幸的是 <app name> 已停止

Posted 2023-02-25

【中文标题】谁能帮助我的第一个 WebView 我被这个问题困住了？不幸的是 <app name> 已停止

【英文标题】：Can anyone help my first WebView i am stucked witht this issue ? Unfortunately <app name> has stopped

【发布时间】：2016-06-18 06:44:45

【问题描述】：

1-content_main.xml

<RelativeLayout
            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_
            android:layout_
            android:paddingBottom="@dimen/activity_vertical_margin"
            android:paddingLeft="@dimen/activity_horizontal_margin"
            android:paddingRight="@dimen/activity_horizontal_margin"
            android:paddingTop="@dimen/activity_vertical_margin"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            tools:context="mx.newmx.MainActivity"
            tools:showIn="@layout/activity_main">   
            <WebView
            android:layout_
            android:layout_
            android:id="@+id/activity_main_webview" /> 
 </RelativeLayout>

2-manifest.xml 文件

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="mx.newmx">
<application
android:allowBackup="true"
android:largeHeap="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/Theme.AppCompat">
<activity
android:name="mx.newmx.MainActivity"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar">
<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>

3-MainActivity.java文件代码

package mx.newmx;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.webkit.WebSettings;
import android.webkit.WebView;
public class MainActivity extends AppCompatActivity 
private WebView myWebView ;
@Override
protected void onCreate(Bundle savedInstanceState) 
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() 
@Override
public void onClick(View view) 
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();

);
myWebView = (WebView) myWebView.findViewById(R.id.activity_main_webview);
WebSettings webSettings = myWebView.getSettings();
webSettings.setjavascriptEnabled(true);
myWebView.loadUrl("http://www.moneyx.pk/");

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

@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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) 
return true;

return super.onOptionsItemSelected(item);

4-我的日志请检查这个

03-04 14:48:25.448 7418-7418/mx.newmx W/AwContents: onDetachedFromWindow called when already detached. Ignoring
03-04 14:48:25.468 7418-7418/mx.newmx D/AndroidRuntime: Shutting down VM
03-04 14:48:25.469 7418-7418/mx.newmx E/AndroidRuntime: FATAL EXCEPTION: main
Process: mx.newmx, PID: 7418
java.lang.RuntimeException: Unable to start activity ComponentInfomx.newmx/mx.newmx.MainActivity: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.webkit.WebView.findViewById(int)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.webkit.WebView.findViewById(int)' on a null object reference
at mx.newmx.MainActivity.onCreate(MainActivity.java:30)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
at android.app.ActivityThread.-wrap11(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5417) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 

这就是我创建我的第一个 WebView 的方式，但不幸的是应用程序名称已停止，这会产生错误，请任何人检查代码的问题所在，以便我可以继续

这就是我创建我的第一个 WebView 的方式，但不幸的是应用程序名称已停止，这会产生错误，请任何人检查代码的问题所在，以便我可以继续

【问题讨论】：

检查 *** 上的 java.lang.NullPointerException: 是什么。你得到了这个例外。

你能帮忙解决什么问题吗？

myWebView = (WebView) findViewById(R.id.activity_main_webview);

【参考方案1】：

myWebView = (WebView) myWebView.findViewById(R.id.activity_main_webview);

删除 myWebView 只使用这样的 findViewById

 myWebView = (WebView) findViewById(R.id.activity_main_webview);

【参考方案2】：

您正在膨胀不同的布局。请检查

setContentView(R.layout.activity_main);

【讨论】：

你能解释一下是什么吗？

我认为你在不包含 webview 的活动中夸大了不同的布局..请检查

还是一样，我改了这个也没有运气