这是日志。有人可以告诉我为什么会这样吗？
07-29 18:20:44.109: D/AndroidRuntime(8836): Shutting down VM
07-29 18:20:44.109: W/dalvikvm(8836): threadid=1: thread exiting with uncaught exception (group=0x41443300)
07-29 18:20:44.109: E/AndroidRuntime(8836): FATAL EXCEPTION: main
07-29 18:20:44.109: E/AndroidRuntime(8836): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.liamwli.parent.trap/com.liamwli.parent.trap.ParentTrap}: java.lang.ClassCastException: com.liamwli.parent.trap.ParentTrap cannot be cast to android.app.Activity
07-29 18:20:44.109: E/AndroidRuntime(8836): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2096)
07-29 18:20:44.109: E/AndroidRuntime(8836): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2207)
07-29 18:20:44.109: E/AndroidRuntime(8836): at android.app.ActivityThread.access$600(ActivityThread.java:139)
07-29 18:20:44.109: E/AndroidRuntime(8836): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1205)
07-29 18:20:44.109: E/AndroidRuntime(8836): at android.os.Handler.dispatchMessage(Handler.java:99)
07-29 18:20:44.109: E/AndroidRuntime(8836): at android.os.Looper.loop(Looper.java:137)
07-29 18:20:44.109: E/AndroidRuntime(8836): at android.app.ActivityThread.main(ActivityThread.java:4896)
07-29 18:20:44.109: E/AndroidRuntime(8836): at java.lang.reflect.Method.invokeNative(Native Method)
07-29 18:20:44.109: E/AndroidRuntime(8836): at java.lang.reflect.Method.invoke(Method.java:511)
07-29 18:20:44.109: E/AndroidRuntime(8836): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:788)
07-29 18:20:44.109: E/AndroidRuntime(8836): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555)
07-29 18:20:44.109: E/AndroidRuntime(8836): at dalvik.system.NativeStart.main(Native Method)
07-29 18:20:44.109: E/AndroidRuntime(8836): Caused by: java.lang.ClassCastException: com.liamwli.parent.trap.ParentTrap cannot be cast to android.app.Activity
07-29 18:20:44.109: E/AndroidRuntime(8836): at android.app.Instrumentation.newActivity(Instrumentation.java:1053)
07-29 18:20:44.109: E/AndroidRuntime(8836): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2087)
07-29 18:20:44.109: E/AndroidRuntime(8836): ... 11 more
和活动：
package com.liamwli.parent.trap;
import android.os.Bundle;
import android.app.Activity;
import android.app.admin.DeviceAdminReceiver;
import android.app.admin.DevicePolicyManager;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import android.support.v4.app.NavUtils;
class ParentTrap extends Activity {
Button dae, dad, spass;
EditText pass;
ComponentName mDeviceAdminSample;
static final int RESULT_ENABLE = 1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
dae = (Button) findViewById(R.id.benablea);
dae.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
mDeviceAdminSample = new ComponentName(ParentTrap.this,
Controller.class);
Intent intent = new Intent(
DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN,
mDeviceAdminSample);
intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION,
"Title");
startActivityForResult(intent, RESULT_ENABLE);
}
});
dad = (Button) findViewById(R.id.button1);
dad.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
}
});
spass = (Button) findViewById(R.id.button2);
spass.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
}
});
pass = (EditText) findViewById(R.id.editText1);
dad.setEnabled(false);
}
public class Controller extends DeviceAdminReceiver {
void showToast(Context context, String msg) {
String status = "Status";
Toast.makeText(context, status, Toast.LENGTH_SHORT).show();
}
@Override
public void onEnabled(Context context, Intent intent) {
showToast(context, "Enabled");
}
@Override
public CharSequence onDisableRequested(Context context, Intent intent) {
return "Disable Requested";
}
@Override
public void onDisabled(Context context, Intent intent) {
showToast(context, "Disabled");
}
@Override
public void onPasswordChanged(Context context, Intent intent) {
showToast(context, "Device PIN Changed");
}
}
}
class evilliam {
}
// @Override
// public boolean onCreateOptionsMenu(Menu menu) {
// getMenuInflater().inflate(R.menu.main, menu);
// return true;
// }
谢谢您的帮助-我一直在尝试遵循dev docs：/
新日志：
07-29 18:43:25.404: D/dalvikvm(13404): newInstance failed: Lcom/liamwli/parent/trap/ParentTrap; not accessible to Landroid/app/Instrumentation;
07-29 18:43:25.404: D/AndroidRuntime(13404): Shutting down VM
07-29 18:43:25.404: W/dalvikvm(13404): threadid=1: thread exiting with uncaught exception (group=0x41443300)
07-29 18:43:25.419: E/AndroidRuntime(13404): FATAL EXCEPTION: main
07-29 18:43:25.419: E/AndroidRuntime(13404): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.liamwli.parent.trap/com.liamwli.parent.trap.ParentTrap}: java.lang.IllegalAccessException: access to class not allowed
07-29 18:43:25.419: E/AndroidRuntime(13404): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2096)
07-29 18:43:25.419: E/AndroidRuntime(13404): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2207)
07-29 18:43:25.419: E/AndroidRuntime(13404): at android.app.ActivityThread.access$600(ActivityThread.java:139)
07-29 18:43:25.419: E/AndroidRuntime(13404): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1205)
07-29 18:43:25.419: E/AndroidRuntime(13404): at android.os.Handler.dispatchMessage(Handler.java:99)
07-29 18:43:25.419: E/AndroidRuntime(13404): at android.os.Looper.loop(Looper.java:137)
07-29 18:43:25.419: E/AndroidRuntime(13404): at android.app.ActivityThread.main(ActivityThread.java:4896)
07-29 18:43:25.419: E/AndroidRuntime(13404): at java.lang.reflect.Method.invokeNative(Native Method)
07-29 18:43:25.419: E/AndroidRuntime(13404): at java.lang.reflect.Method.invoke(Method.java:511)
07-29 18:43:25.419: E/AndroidRuntime(13404): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:788)
07-29 18:43:25.419: E/AndroidRuntime(13404): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555)
07-29 18:43:25.419: E/AndroidRuntime(13404): at dalvik.system.NativeStart.main(Native Method)
07-29 18:43:25.419: E/AndroidRuntime(13404): Caused by: java.lang.IllegalAccessException: access to class not allowed
07-29 18:43:25.419: E/AndroidRuntime(13404): at java.lang.Class.newInstanceImpl(Native Method)
07-29 18:43:25.419: E/AndroidRuntime(13404): at java.lang.Class.newInstance(Class.java:1319)
07-29 18:43:25.419: E/AndroidRuntime(13404): at android.app.Instrumentation.newActivity(Instrumentation.java:1053)
07-29 18:43:25.419: E/AndroidRuntime(13404): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2087)
07-29 18:43:25.419: E/AndroidRuntime(13404): ... 11 more
07-29 18:43:27.214: I/Process(13404): Sending signal. PID: 13404 SIG: 9
最佳答案
看来您的应用程序假设ParentTrap是一个Activity（不是，Controller是Activity），您可以：
从ParentTrap的声明中删除public：
class ParentTrap extends DeviceAdminReceiver {
并将Controller设为
public类（即主类）：public class Controller extends Activity {
将ParentTrap类嵌套在Controller中：
public class Controller extends Activity {
public class ParentTrap extends DeviceAdminReceiver {...}
...
}
将ParentTrap放入其自己的文件（ParentTrap.java）