1. 技术文章
  2. creating a DialogPreference from XML

creating a DialogPreference from XML

由 淺唱寂寞╮ 提交于 2019-11-27 03:39:31
Marc Holder Kluver

This one is weird, you need to subclass DialogPreference. The subclass does not need to do anything. So

public class MyDialogPreference extends DialogPreference {

    public MyDialogPreference(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
    }

}

can be instantiated. While a plane old DialogPreference can not. Very weird, they should be the exact same thing.

arberg

Here is an example of how to use the dialog preference (subclassing as you mentioned). 

package dk.myapp.views;

import android.content.Context;
import android.preference.DialogPreference;
import android.util.AttributeSet;

/**
 * The OptionDialogPreference will display a dialog, and will persist the
 * <code>true</code> when pressing the positive button and <code>false</code>
 * otherwise. It will persist to the android:key specified in xml-preference.
 */
public class OptionDialogPreference extends DialogPreference {

    public OptionDialogPreference(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onDialogClosed(boolean positiveResult) {
        super.onDialogClosed(positiveResult);
        persistBoolean(positiveResult);
    }

}

The preferences.xml should contain

<dk.myapp.views.OptionDialogPreference
            android:key="@string/prefKeyResetQuests"
            android:dialogIcon="@android:drawable/ic_dialog_alert"
            android:title="Reset Quests"
            android:summary="Reset all quest-progress."
            android:dialogMessage="Are you sure you wish to reset your quest progress? This action cannot be undone!"
            android:positiveButtonText="Clear Quests"
            android:negativeButtonText="Cancel"/>

I have a res/value containing (though the key-name can also be declared explicitly above).

<string name="prefKeyResetQuests">resetQuests</string>

My PreferenceActivity does the actual resetting from onPause. Note that onStop may be too late since the onStop will not always be called immediately after pressing back:

@Override
public void onPause() {
    SharedPreferences prefs = android.preference.PreferenceManager.
        getDefaultSharedPreferences(getBaseContext());
    if(prefs.getBoolean(
        getResources().getString(R.string.prefKeyResetQuests), false)) {
        // apply reset, and then set the pref-value back to false
    }
}

Or equivalently since we are still in the PreferenceActivity:

@Override
protected void onPause() {
    Preference prefResetQuests =
        findPreference(getResources().getString(R.string.prefKeyResetQuests));
    if(prefResetQuests.getSharedPreferences().
        getBoolean(prefResetQuests.getKey(), false)){
        // apply reset, and then set the pref-value back to false 
    }
}
SKf

First:

Create your own class which extends DialogPreference as bellow:

package com.test.view;

import android.preference.DialogPreference;

public class DialogExPreference extends DialogPreference 
{
    public DialogExPreference(Context oContext, AttributeSet attrs)
    {
        super(oContext, attrs);     
    }
}

Second:

Modify the xml file as bellow:

<PreferenceScreen
    xmlns:android="http://schemas.android.com/apk/res/android">

    <com.test.view.DialogExPreference
        android:title="@string/title"
        android:dialogMessage="@string/lite"              
                android:negativeButtonText="test"/> 

</PreferenceScreen>

Then it's OK.

标签
android
xml
preference
易学教程内所有资源均来自网络或用户发布的内容，如有违反法律规定的内容欢迎反馈！
该文章没有解决你所遇到的问题?点击提问,说说你的问题,让更多的人一起探讨吧!