我已经看到许多定制的解决方案和对此问题的答案。我需要一个非常简单的东西，我有一个偏好设置活动，我所需要的只是其中一个选项将打开带有数字选择器的对话框并保存结果。您能逐步指导我如何完成此工作吗？
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>
号码选择器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>
子类DialogPreference，以构建自己的NumberPickerPreference。
我为您实施了以下一项。它工作正常，但功能不完整。例如，最小值和最大值是硬编码的常数。这些实际上应该是首选项xml声明上的属性。为了使它正常工作，您需要添加一个attrs.xml文件，指定您的自定义属性。
有关支持库项目中的自定义xml属性的NumberPicker首选项小部件的完整实现，以及演示如何使用它的演示应用程序，请参见GitHub：https://github.com/Alobar/AndroidPreferenceTest
您将使用该小部件作为其他任何首选项小部件，除非您必须完全限定名称：
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;
}
}
实施DialogPreference是一种解决方案：
基于ListPreference的简单解决方案，动态添加值/条目：
root_preferences.xml：
<PreferenceScreen xmlns:app="http://schemas.android.com/apk/res-auto"
...
<ListPreference
app:key="myNumber"
app:title="my title"
app:useSimpleSummaryProvider="true"/>
SettingsActivity.java：
public class SettingsFragment extends PreferenceFragmentCompat {
@Override
public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
setPreferencesFromResource(R.xml.root_preferences, rootKey);
ListPreference e = findPreference("myNumber");
if (e != null) {
String[] vals = new String[100];
for (int i = 0; i < vals.length; i++)
vals[i] = String.valueOf(i + 1);
e.setEntries(vals);
e.setEntryValues(vals);
e.setDefaultValue("1");
}
}
...
}