NoClassDefFoundError：失败的解决方案：Landroid / support / v7 / appcompat / R $styleable
作者：互联网
新手试图完成我的第一个由谷歌提供的应用程序教程.在去往这个致命异常的路上,我确实导入了很多随机软件包来摆脱许多事情的“无法解决”错误,ActionBarActivity,EditText,Fragment,LayoutInflater等,但不确定这是否重要.无论如何,当我点击主活动中的“发送”按钮时,我的应用程序崩溃并产生致命异常.这是我的代码和logcat文件.
MyActivity.java(本教程的MainActivity.java)
package magiccoupons.tutapp;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
public class MyActivity extends Activity {
public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.my, 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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
}
DisplayMessageActivity.java：
package magiccoupons.tutapp;
import android.widget.*;
import android.content.Intent;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.*;
import android.support.v7.app.ActionBarActivity;
import android.app.Fragment;
public class DisplayMessageActivity extends ActionBarActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get the message from the intent
Intent intent = getIntent();
String message = intent.getStringExtra(MyActivity.EXTRA_MESSAGE);
// Create the text view
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(message);
// Set the text view as the activity layout
setContentView(textView);
}
@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);
}
/**
* A placeholder fragment containing a simple view.
*
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() { }
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_display_message,
container, false);
return rootView;
}
}
*/
}
的build.gradle：
apply plugin: 'com.android.application'
android {
compileSdkVersion 'android-L'
buildToolsVersion '20'
defaultConfig {
applicationId "magiccoupons.tutapp"
minSdkVersion 20
targetSdkVersion 20
versionCode 1
versionName "1.0"
}
buildTypes {
release {
runProguard false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:support-v4:20.0.0'
//compile 'com.android.support:appcompat-v7:21.0.0-rc1'
}
activity_my.xml：
<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"
android:orientation="horizontal"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="magiccoupons.tutapp.MainActivity">
<EditText android:id="@+id/edit_message"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="@string/edit_message" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/button_send"
android:onClick="sendMessage" />
</LinearLayout>
activity_display_message.xml：
<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"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context="magiccoupons.tutapp.DisplayMessageActivity">
<TextView
android:text="@string/hello_world"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
和logcat：
08-21 11:24:36.088 3645-3645/magiccoupons.tutapp I/Process﹕ Sending signal. PID: 3645 SIG: 9
08-21 11:37:33.584 4149-4149/magiccoupons.tutapp W/Resources﹕ Preloaded drawable resource #0x1080093 (android:drawable/sym_def_app_icon) that varies with configuration!!
08-21 11:37:33.676 4149-4149/magiccoupons.tutapp I/am_on_resume_called﹕ [0,magiccoupons.tutapp.MyActivity]
08-21 11:37:33.905 4149-4149/magiccoupons.tutapp D/gralloc_goldfish﹕ Emulator without GPU emulation detected.
08-21 11:37:38.139 4149-4149/magiccoupons.tutapp I/am_on_paused_called﹕ [0,magiccoupons.tutapp.MyActivity]
08-21 11:37:38.218 4149-4149/magiccoupons.tutapp I/Choreographer﹕ Skipped 75 frames! The application may be doing too much work on its main thread.
08-21 11:37:38.356 4149-4149/magiccoupons.tutapp D/AndroidRuntime﹕ Shutting down VM
08-21 11:37:38.369 4149-4149/magiccoupons.tutapp E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: magiccoupons.tutapp, PID: 4149
java.lang.NoClassDefFoundError: Failed resolution of: Landroid/support/v7/appcompat/R$styleable;
at android.support.v7.app.ActionBarActivityDelegate.onCreate(ActionBarActivityDelegate.java:106)
at android.support.v7.app.ActionBarActivityDelegateICS.onCreate(ActionBarActivityDelegateICS.java:57)
at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:99)
at magiccoupons.tutapp.DisplayMessageActivity.onCreate(DisplayMessageActivity.java:15)
at android.app.Activity.performCreate(Activity.java:5720)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1102)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2208)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2317)
at android.app.ActivityThread.access$800(ActivityThread.java:143)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5070)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:836)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:631)
Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.v7.appcompat.R$styleable" on path: DexPathList[[zip file "/data/app/magiccoupons.tutapp-1.apk"],nativeLibraryDirectories=[/data/app-lib/magiccoupons.tutapp-1, /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.support.v7.app.ActionBarActivityDelegate.onCreate(ActionBarActivityDelegate.java:106)
at android.support.v7.app.ActionBarActivityDelegateICS.onCreate(ActionBarActivityDelegateICS.java:57)
at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:99)
at magiccoupons.tutapp.DisplayMessageActivity.onCreate(DisplayMessageActivity.java:15)
at android.app.Activity.performCreate(Activity.java:5720)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1102)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2208)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2317)
at android.app.ActivityThread.access$800(ActivityThread.java:143)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5070)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:836)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:631)
Suppressed: java.lang.ClassNotFoundException: android.support.v7.appcompat.R$styleable
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)
... 18 more
Caused by: java.lang.NoClassDefFoundError: Class "Landroid/support/v7/appcompat/R$styleable;" not found
... 22 more
对不起,如果我错过了什么,这个问题是完全没必要和/或欺骗.谢谢.
解决方法:
由于以下原因,您收到该错误：
在您的Gradle构建文件中,您的应用程序正在定位并使用仍处于开发阶段的Android测试版进行编译：
compileSdkVersion 'android-L'
buildToolsVersion '20'
以及
minSdkVersion 20
targetSdkVersion 20
首先要注意的是,在没有安装android-L的设备上,此应用程序将无法正常运行(此时).
您的问题的真正关键在于DisplayMessageActivity,它通过继承扩展
[ActionBarActivity]
标签：android,android-studio,android-activity,android-appcompat 来源： https://codeday.me/bug/20190926/1819430.html