問題描述

如果我使用 Activity 實例，我可以顯示對話框，但是當我使用 Context 或 Application Context 實例時，對話框沒有顯示.

I could show dialog if I uses an Activity instance but when I uses Context or Application Context instance Dialog is not showing.

AlertDialog.Builder builder = new AlertDialog.Builder(activity);
            builder.setTitle(title);
            builder.setMessage(msg);

            if (null != positiveLabel) {
                builder.setPositiveButton(positiveLabel, new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                        dialog.cancel();
                        if (null != listener) {
                            listener.onOk();
                        }
                    }
                });
            }

            if (null != negativeLable) {
                builder.setNegativeButton(negativeLable, new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                        dialog.cancel();
                        if (null != listener) {
                            listener.onCancel();
                        }
                    }
                });
            }

            builder.create().show();

你能不能給我一個解決方案來顯示對話框而不使用 Activity 實例

Can you please give me a solution to show dialog without using Activity instance

推薦答案

這個問題也是我最近遇到的問題，沒有Activity實例就不能創建對話框.getApplicationContext() 調用也不起作用.我這樣做的方法是從一個活動調用創建對話框的方法，并傳遞this"，即對該活動的引用作為參數.

The problem is something I faced recently too, you cant create a dialog without and activity instance. getApplicationContext() call doesn't work too. The way I did this is to make the call to a method that creates the dialog, from an activity, and pass "this" i.e. the reference to that activity as a parameter.

如果您打算重用此代碼，作為可重用組件或作為在多個位置創建對話框的機制，請創建一個基本活動類并在其中包含此方法，并根據需要在子類活動中使用它.

If you are going to reuse this code, as a reusable component or as a mechanism to create dialogs at multiple places, create a base activity class and have this method in there, and use it in sub-classed activities as needed.

這篇關于僅使用 Context 而不是 Activity 實例顯示對話框的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！