Android service里面启动activity和alertdialog

启动activity源码:(记得要加上Intent.FLAG_ACTIVITY_NEW_TASK)

						Intent intent = new Intent();
						intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
						intent.setClass(getApplicationContext(),FileBrowserActivity.class);
						startActivity(intent);

启动alertDialog源码:

		AlertDialog.Builder builder = new AlertDialog.Builder(this);
		builder.setMessage("是否接受文件?")
				.setPositiveButton("是", new DialogInterface.OnClickListener() {
					@Override
					public void onClick(DialogInterface dialog, int which) {

					}
				}).setNegativeButton("否", new OnClickListener() {
					@Override
					public void onClick(DialogInterface dialog, int which) {
					}
				});
		AlertDialog ad = builder.create();
//		ad.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_DIALOG); //系统中关机对话框就是这个属性 
		ad.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
		ad.setCanceledOnTouchOutside(false);                                   //点击外面区域不会让dialog消失
		ad.show();

还要加上权限

    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />