启动对话框结果 [英] Start dialog for result

问题描述

我创建了一个名为NumericPicker类，这是在对话框中创建。但它可以在任何活动中使用，所以我不希望使用任何类型的对象或数据集的类。
问题是我需要在活动的方式，当对话框关闭知道这样我就可以救我所需要的值（如 startActivityForResult（））。我想我可以在类扩展到活动，并设置主题，以对话，但是这不是想法，类不应该延长活动。

I have created a Class named NumericPicker, which is created in a Dialog. But it can be used in any Activity so I don't want to use any type of Object or Dataset in the Class. The problem is I need to have in the Activity a way to know when the Dialog is closed so I could save the values I need (like startActivityForResult()). I think I could extend the Class to Activity and set the Theme to Dialog, but that's not the idea, the Class should not extend Activity.

任何建议这样做吗？

推荐答案

实施自己的监听器/回调。例如，创建一个onCloseListener接口。您的活动将实现接口，并在对话框实现了 setOnCloseListener 方法。在创建对话框中，指定活动为onCloseListener，当对话框关闭，它调用您的活动实现的接口方法。

Implement your own listener/callback. For example, create an onCloseListener interface. Your activity will implement the interface, and the dialog implements a setOnCloseListener method. When creating the dialog, you assign the activity as the onCloseListener, and when the dialog is closing, it calls the interface method implemented in your activity.

下面是一个监听器接口和实现所谓DrawView自定义视图的内声明的例子：

Here's an example of a listener interface and implementation declared inside of a custom view called DrawView:

public interface OnUndoEventListener {
    public abstract void onUndoEvent();
}

ListenerInfo getListenerInfo() {
    if (mListenerInfo != null) {
        return mListenerInfo;
    }
    mListenerInfo = new ListenerInfo();
    return mListenerInfo;
}

public void setOnUndoEventListener(OnUndoEventListener l) {
    getListenerInfo().mOnUndoEventListener = l;
}

static class ListenerInfo {
    private OnUndoEventListener mOnUndoEventListener;
}

ListenerInfo mListenerInfo;

这是一个活动的实施申报和设置监听器：

This is an activity's implementation declaration and setting the listener:

public class MyActivity extends Activity implements DrawView.OnUndoEventListener {
...
@Override
protected void onCreate(Bundle savedInstanceState) {
        ...
    mDrawView = new DrawView(this, ...);
mDrawView.setOnUndoEventListener(this);

    ...
    };

@Override
public void onUndoEvent() {
    ...
}
...
}

调用回调DrawView：

Invoking the callback in DrawView:

private void someMethod(){

    if (getListenerInfo().mOnUndoEventListener != null)
        getListenerInfo().mOnUndoEventListener.onUndoEvent();

....

};

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