問題描述

我已經看到了許多針對這個問題的定制解決方案和答案.我需要一些非常簡單的東西，我有一個偏好活動，我所需要的只是其中一個選項將打開帶有數字選擇器的對話框并保存結果.你能指導我一步一步地完成這個嗎?

I have seen many customized solutions and answers to this question. I need something very simple, I have a preference activity and all I need is that one of the options will open dialog with a number picker and save the results. Can you please guide me step by step with how to accomplish this?

public class SettingsActivity extends PreferenceActivity
{
    @Override
    protected void onCreate(final Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        getFragmentManager().beginTransaction().replace(android.R.id.content, new MyPreferenceFragment()).commit();
        //requestWindowFeature(Window.FEATURE_NO_TITLE);    
    }

    public static class MyPreferenceFragment extends PreferenceFragment
    {
        @Override
        public void onCreate(final Bundle savedInstanceState)
        {
            super.onCreate(savedInstanceState);
            addPreferencesFromResource(R.xml.prefs);

        }
    }

}

XML:

    <SwitchPreference
        android:key="cross"
        android:summaryOff="Cross is invisible"
        android:summaryOn="Cross is visible"
        android:switchTextOff="OFF"
        android:switchTextOn="ON"
        android:title="Cross" 
        android:defaultValue="true"/>

    <SwitchPreference
        android:key="autoP"
        android:summaryOff="App will go to sleep"
        android:summaryOn="App will not go to sleep"
        android:switchTextOff="OFF"
        android:switchTextOn="ON"
        android:title="Always On" 
        android:defaultValue="true"/>

    <SwitchPreference
        android:key="tempD"
        android:summaryOff="Temprature not displayed"
        android:summaryOn="Temprature displayed"
        android:switchTextOff="OFF"
        android:switchTextOn="ON"
        android:title="Tempature Display" 
        android:defaultValue="true"/>

    <ListPreference
        android:entries="@array/units"
        android:entryValues="@array/lunits"
        android:key="listUnits"
        android:summary="Units schosssing"
        android:title="Units" android:defaultValue="C"/>

     <!--Need to add button to open dialog-->       

</PreferenceScreen>

數字選擇器 XML:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <NumberPicker
        android:id="@+id/numberPicker1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="64dp" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/numberPicker1"
        android:layout_marginLeft="20dp"
        android:layout_marginTop="98dp"
        android:layout_toRightOf="@+id/numberPicker1"
        android:text="Cancel" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/button2"
        android:layout_alignBottom="@+id/button2"
        android:layout_marginRight="16dp"
        android:layout_toLeftOf="@+id/numberPicker1"
        android:text="Set" />

</RelativeLayout>

推薦答案

子類 DialogPreference 來構建您自己的 NumberPickerPreference.

Subclass DialogPreference to build your own NumberPickerPreference.

我在下面為您實現了一個.它工作得很好，但功能不完整.例如，最小值和最大值是硬編碼的常量.這些實際上應該是首選項 xml 聲明中的屬性.要讓它工作，您需要添加一個 attrs.xml 文件來指定您的自定義屬性.

I have implemented one below for you. It works perfectly fine, but is not feature complete. For example the minimum and maximum values are hard-coded constants. These should really be attributes on the preference xml declaration. To get that to work you would need to add an attrs.xml file specifying your custom attributes.

有關在庫項目中支持自定義 xml 屬性的 NumberPicker 首選項小部件的完整實現以及展示如何使用它的演示應用，請參閱 GitHub:https://github.com/Alobar/AndroidPreferenceTest

For the full implementation of the NumberPicker preference widget that supports custom xml attributes in a library project and a demo app showing how to use it, see GitHub: https://github.com/Alobar/AndroidPreferenceTest

您可以將該小部件用作任何其他首選項小部件，除非您必須完全限定名稱:

You would use the widget as any other preference widget, except you have to fully qualify the name:

preferences.xml

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

    <com.example.preference.NumberPickerPreference
        android:key="key_number"
        android:title="Give me a number"
        android:defaultValue="55" />

</PreferenceScreen>

NumberPickerPreference.java

package com.example.preference;

import android.content.Context;
import android.content.res.TypedArray;
import android.preference.DialogPreference;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.NumberPicker;

/**
 * A {@link android.preference.Preference} that displays a number picker as a dialog.
 */
public class NumberPickerPreference extends DialogPreference {

    // allowed range
    public static final int MAX_VALUE = 100;
    public static final int MIN_VALUE = 0;
    // enable or disable the 'circular behavior'
    public static final boolean WRAP_SELECTOR_WHEEL = true; 

    private NumberPicker picker;
    private int value;

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

    public NumberPickerPreference(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected View onCreateDialogView() {
        FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(
                ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        layoutParams.gravity = Gravity.CENTER;

        picker = new NumberPicker(getContext());
        picker.setLayoutParams(layoutParams);

        FrameLayout dialogView = new FrameLayout(getContext());
        dialogView.addView(picker);

        return dialogView;
    }

    @Override
    protected void onBindDialogView(View view) {
        super.onBindDialogView(view);
        picker.setMinValue(MIN_VALUE);
        picker.setMaxValue(MAX_VALUE);
        picker.setWrapSelectorWheel(WRAP_SELECTOR_WHEEL);
        picker.setValue(getValue());
    }

    @Override
    protected void onDialogClosed(boolean positiveResult) {
        if (positiveResult) {
            picker.clearFocus();
            int newValue = picker.getValue();
            if (callChangeListener(newValue)) {
                setValue(newValue);
            }
        }
    }

    @Override
    protected Object onGetDefaultValue(TypedArray a, int index) {
        return a.getInt(index, MIN_VALUE);
    }

    @Override
    protected void onSetInitialValue(boolean restorePersistedValue, Object defaultValue) {
        setValue(restorePersistedValue ? getPersistedInt(MIN_VALUE) : (Integer) defaultValue);
    }

    public void setValue(int value) {
        this.value = value;
        persistInt(this.value);
    }

    public int getValue() {
        return this.value;
    }
}

這篇關于帶有數字選擇器的 Android PreferenceActivity 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！