1、一般使用AlertDialog.Builder builder = new Builder(context)是这样的。需要修改为：AlertDialog.Builder builder = new Builder(context,android.R.style.Theme_Holo_Light_Dialog);
2、还要修改背景和type方式dialog.getWindow().setBackgroundDrawableResource(android.R.color.transparent); dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
3、整体代码如下：AlertDialog.Builder builder = new Builder(context,android.R.style.Theme_Holo_Light_Dialog); builder.setIcon(android.R.drawable.ic_dialog_info); builder.setMessage(R.string.msg_forceoff_login); builder.setCancelable(false); builder.setPositiveButton(R.string.ok, new OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }); AlertDialog dialog = builder.create(); dialog.getWindow().setBackgroundDrawableResource(android.R.color.transparent); dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT); dialog.show();
4、AndroidManifest.xml中添加权限 <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" /> <uses-permission android:name="android.permission.SYSTEM_OVERLAY_WINDOW" />