Android系统有Activity、BroadcastReceiver、Service和ContentProvider四个组件(Component)。
通常这些组件都会配置在AndroidManifest.xml文件中,可以使用PackageManager类的setComponentEnabledSetting方法来动态启用和禁用Application中的某个组件。
1、AndroidManifest.xml中配置android:enabled属性
android:enabled=”false”,禁用组件
<activity
android:configChanges="keyboardHidden|orientation"
android:enabled="false"
android:name="DynamicActivity" >
</activity>
2、PackageManager类用于启用和禁用组件的相关代码
package com.orgcent.dynamicicon;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
/**
* 在AndroidManifest.xml中设置Component的android:enabled属性来启用和禁用组建
*/
public class DynamicEnableActivity extends Activity implements OnClickListener {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button btn = findView(this, R.id.btnStart);
btn.setOnClickListener(this);
btn = findView(this, R.id.btnToggle);
btn.setOnClickListener(this);
}
@SuppressWarnings("unchecked")
private final <T> T findView(Activity cx, int resId) {
T findViewById = (T) cx.findViewById(resId);
return findViewById;
}
//获取activity在androidManifest.xml中的配置信息
private ActivityInfo getActivityInfo(ComponentName name) {
final PackageManager pm = getPackageManager();
try {
return pm.getActivityInfo(name, PackageManager.GET_META_DATA);
} catch (Exception e) {
}
return null;
}
@Override
public void onClick(View v) {
final PackageManager pm = getPackageManager();
final ComponentName comptName = new ComponentName(this,
DynamicActivity.class);
final ActivityInfo info = getActivityInfo(comptName);
switch (v.getId()) {
case R.id.btnStart:
if (null != info) { System.out.println(info.enabled);
Intent it = new Intent();
it.setComponent(comptName);
startActivity(it);
} else {
Toast.makeText(this, "组件已禁用,无法使用", Toast.LENGTH_LONG).show();
}
break;
case R.id.btnToggle:
if (null == info) {
// PackageManager.DONT_KILL_APP,表示更改Component状态后,不杀死应用。禁用某些组件可能导致正在运行的应用无法使用某功能。
pm.setComponentEnabledSetting(comptName,
PackageManager.COMPONENT_ENABLED_STATE_ENABLED,
PackageManager.DONT_KILL_APP);
Toast.makeText(this, "组件已启用", Toast.LENGTH_LONG).show();
} else {
pm.setComponentEnabledSetting(comptName,
PackageManager.COMPONENT_ENABLED_STATE_DISABLED,
PackageManager.DONT_KILL_APP);
Toast.makeText(this, "组件已禁用", Toast.LENGTH_LONG).show();
}
break;
}
}
}