首先AndroidManifest.xml中加入权限:
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"></uses-permission>
下面是简单实例:
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setIcon(R.drawable.ic);
builder.setTitle("标题");
builder.setMessage("消息");
builder.setPositiveButton(R.string.btn_update, new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
//增加按钮,回调事件
}
);
builder.setCancelable(false);//弹出框不可以换返回键取消
AlertDialog dialog = builder.create();
dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);//将弹出框设置为全局
dialog.setCanceledOnTouchOutside(false);//失去焦点不会消失
dialog.show();