我正在尝试为我的应用添加工具栏。我一直在关注一个教程，但我仍然无法让它工作。我会发布我认为与错误有关的代码，但如果你还需要其他任何东西，请告诉我。
MainActivity.java：
package riveras.kasparsweblser;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.KeyEvent;
import android.view.MenuItem;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.support.v7.widget.Toolbar;
public class MainActivity extends AppCompatActivity {
WebView webview;
private WebView mWebView;
private Toolbar toolbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar= (Toolbar) findViewById(R.id.app_bar);
setSupportActionBar(toolbar);
String url = "http://www.google.com";
webview = (WebView) findViewById(R.id.wv);
webview.getSettings().setJavaScriptEnabled(true);
webview.loadUrl(url);
webview.setWebChromeClient(new WebChromeClient());
webview.setWebViewClient(new WebViewClient());
}
@Override //Add menu items later
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
return super.onOptionsItemSelected(item);
}
@Override //Go to previous page when Back is clicked
public boolean onKeyDown(int keyCode, KeyEvent event) {
mWebView = (WebView) findViewById(R.id.wv);
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (keyCode) {
case KeyEvent.KEYCODE_BACK:
if (mWebView.canGoBack()) {
mWebView.goBack();
} else {
finish();
}
return true;
}
}
return super.onKeyDown(keyCode, event);
}
}
activity_main.xml中：
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
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" android:fitsSystemWindows="true"
tools:context=".MainActivity">
<RelativeLayout 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"
tools:context=".MainActivity" >
<include
android:id="@+id/app_bar"
layout="@layout/app_bar" />
<WebView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/wv"
android:layout_alignParentBottom="true"
android:elevation="2dp"
android:layout_gravity="center" />
</RelativeLayout>
</android.support.design.widget.CoordinatorLayout>
app_bar.xml（我要添加的工具栏）：
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v7.Toolbar>
我收到了这个我无法理解的错误：
01-10 19:27:10.842 17194-17194/riveras.kasparsweblser E/AndroidRuntime: FATAL EXCEPTION: main
Process: riveras.kasparsweblser, PID: 17194
java.lang.RuntimeException: Unable to start activity ComponentInfo{riveras.kasparsweblser/riveras.kasparsweblser.MainActivity}: android.view.InflateException: Binary XML file line #2: Error inflating class android.support.v7.Toolbar
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2356)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2418)
at android.app.ActivityThread.access$900(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5291)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)
Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class android.support.v7.Toolbar
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:757)
at android.view.LayoutInflater.parseInclude(LayoutInflater.java:892)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:802)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109)
at riveras.kasparsweblser.MainActivity.onCreate(MainActivity.java:22)
at android.app.Activity.performCreate(Activity.java:5990)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2309)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2418)
at android.app.ActivityThread.access$900(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5291)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)
Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.v7.Toolbar" on path: DexPathList[[zip file "/data/app/riveras.kasparsweblser-2/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
at android.view.LayoutInflater.createView(LayoutInflater.java:571)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:743)
at android.view.LayoutInflater.parseInclude(LayoutInflater.java:892)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:802)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256)
at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109)
at riveras.kasparsweblser.MainActivity.onCreate(MainActivity.java:22)
at android.app.Activity.performCreate(Activity.java:5990)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2309)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2418)
at android.app.ActivityThread.access$900(ActivityThread.java:154)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5291)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)
Suppressed: java.lang.ClassNotFoundException: android.support.v7.Toolbar
at java.lang.Class.classForName(Native Method)
at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
... 25 more
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available
如果有人确实看到了什么错，我会非常感谢知道，任何有助于解决我的问题的事情都值得赞赏。提前谢谢。
答案 0 :(得分：0)
您使用的是错误的包。
在布局aap_bar.xml文件中使用android.support.v7.widget.Toolbar代替android.support.v7.Toolbar。