//在dialog/popUpWindow显示( dialog.show() /popupWindow.showAtLocation())后加入如下代码

Timer timer = new Timer();
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                //设置可获得焦点
                ed_editDialog.setFocusable(true);
                ed_editDialog.setFocusableInTouchMode(true);
                //请求获得焦点
                ed_editDialog.requestFocus();

                //调用系统输入法
                InputMethodManager inputManager = (InputMethodManager) ed_editDialog
                        .getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
                inputManager.showSoftInput(ed_editDialog, 0);
            }
        },200);