android - 我的 PreferenceScreen 上的 slider

Question

我希望我的偏好菜单有一些东西可以改变振动的持续时间。

prefs.xml 没有 slider 标签，那么最好的方法是什么？

Answer 1

我改进了 Macarse 提供的链接，使该值仅在单击确定按钮时保存，以便您可以在 XML 文件中使用 @string/... 值。

代码如下:

/* The following code was written by Matthew Wiggins 
 * and is released under the APACHE 2.0 license 
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Improvements :
 * - save the value on positive button click, not on seekbar change
 * - handle @string/... values in xml file
 */

package fr.atcm.carpooling.views.utils;

import android.app.AlertDialog;
import android.content.Context;
import android.os.Bundle;
import android.preference.DialogPreference;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.SeekBar;
import android.widget.TextView;


public class SeekBarPreference extends DialogPreference implements SeekBar.OnSeekBarChangeListener, OnClickListener
{
    // ------------------------------------------------------------------------------------------
    // Private attributes :
    private static final String androidns="http://schemas.android.com/apk/res/android";

    private SeekBar mSeekBar;
    private TextView mSplashText,mValueText;
    private Context mContext;

    private String mDialogMessage, mSuffix;
    private int mDefault, mMax, mValue = 0;
    // ------------------------------------------------------------------------------------------



    // ------------------------------------------------------------------------------------------
    // Constructor :
    public SeekBarPreference(Context context, AttributeSet attrs) {

        super(context,attrs); 
        mContext = context;

        // Get string value for dialogMessage :
        int mDialogMessageId = attrs.getAttributeResourceValue(androidns, "dialogMessage", 0);
        if(mDialogMessageId == 0) mDialogMessage = attrs.getAttributeValue(androidns, "dialogMessage");
        else mDialogMessage = mContext.getString(mDialogMessageId);

        // Get string value for suffix (text attribute in xml file) :
        int mSuffixId = attrs.getAttributeResourceValue(androidns, "text", 0);
        if(mSuffixId == 0) mSuffix = attrs.getAttributeValue(androidns, "text");
        else mSuffix = mContext.getString(mSuffixId);

        // Get default and max seekbar values :
        mDefault = attrs.getAttributeIntValue(androidns, "defaultValue", 0);
        mMax = attrs.getAttributeIntValue(androidns, "max", 100);
    }
    // ------------------------------------------------------------------------------------------



    // ------------------------------------------------------------------------------------------
    // DialogPreference methods :
    @Override 
    protected View onCreateDialogView() {

        LinearLayout.LayoutParams params;
        LinearLayout layout = new LinearLayout(mContext);
        layout.setOrientation(LinearLayout.VERTICAL);
        layout.setPadding(6,6,6,6);

        mSplashText = new TextView(mContext);
        mSplashText.setPadding(30, 10, 30, 10);
        if (mDialogMessage != null)
            mSplashText.setText(mDialogMessage);
        layout.addView(mSplashText);

        mValueText = new TextView(mContext);
        mValueText.setGravity(Gravity.CENTER_HORIZONTAL);
        mValueText.setTextSize(32);
        params = new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.FILL_PARENT, 
                LinearLayout.LayoutParams.WRAP_CONTENT);
        layout.addView(mValueText, params);

        mSeekBar = new SeekBar(mContext);
        mSeekBar.setOnSeekBarChangeListener(this);
        layout.addView(mSeekBar, new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));

        if (shouldPersist())
            mValue = getPersistedInt(mDefault);

        mSeekBar.setMax(mMax);
        mSeekBar.setProgress(mValue);

        return layout;
    }

    @Override 
    protected void onBindDialogView(View v) {
        super.onBindDialogView(v);
        mSeekBar.setMax(mMax);
        mSeekBar.setProgress(mValue);
    }

    @Override
    protected void onSetInitialValue(boolean restore, Object defaultValue)  
    {
        super.onSetInitialValue(restore, defaultValue);
        if (restore) 
            mValue = shouldPersist() ? getPersistedInt(mDefault) : 0;
            else 
                mValue = (Integer)defaultValue;
    }
    // ------------------------------------------------------------------------------------------



    // ------------------------------------------------------------------------------------------
    // OnSeekBarChangeListener methods :
    @Override
    public void onProgressChanged(SeekBar seek, int value, boolean fromTouch)
    {
        String t = String.valueOf(value);
        mValueText.setText(mSuffix == null ? t : t.concat(" " + mSuffix));
    }

    @Override
    public void onStartTrackingTouch(SeekBar seek) {}
    @Override
    public void onStopTrackingTouch(SeekBar seek) {}

    public void setMax(int max) { mMax = max; }
    public int getMax() { return mMax; }

    public void setProgress(int progress) { 
        mValue = progress;
        if (mSeekBar != null)
            mSeekBar.setProgress(progress); 
    }
    public int getProgress() { return mValue; }
    // ------------------------------------------------------------------------------------------



    // ------------------------------------------------------------------------------------------
    // Set the positive button listener and onClick action : 
    @Override
    public void showDialog(Bundle state) {

        super.showDialog(state);

        Button positiveButton = ((AlertDialog) getDialog()).getButton(AlertDialog.BUTTON_POSITIVE);
        positiveButton.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {

        if (shouldPersist()) {

            mValue = mSeekBar.getProgress();
            persistInt(mSeekBar.getProgress());
            callChangeListener(Integer.valueOf(mSeekBar.getProgress()));
        }

        ((AlertDialog) getDialog()).dismiss();
    }
    // ------------------------------------------------------------------------------------------
}

编辑:

这是截图:

编辑:根据 arlomedia 的要求，这里是所有需要的代码(我刚刚重新创建了一个新项目，它运行良好。我纠正了 SeekBarPreference 类中的一些错误，所以不要忘记重新复制/粘贴它) :

主要 Activity :

package fr.at.testsliderpref;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onMenuItemSelected(int featureId, MenuItem item) {

        switch(item.getItemId()) {

            case R.id.menu_settings : {

                startActivity(new Intent(this, SettingsActivity.class));

                break;
            }
        }

        return true;    
    }
}

设置 Activity :

package fr.at.testsliderpref;

import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.os.Bundle;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
import fr.at.testsliderpref.utils.SeekBarPreference;

public class SettingsActivity extends PreferenceActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        // Call super :
        super.onCreate(savedInstanceState);

        // Set the activity's fragment :
        getFragmentManager().beginTransaction().replace(android.R.id.content, new SettingsFragment()).commit();
    }


    public static class SettingsFragment extends PreferenceFragment implements OnSharedPreferenceChangeListener {

        private SeekBarPreference _seekBarPref;

        @Override
        public void onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);

            // Load the preferences from an XML resource
            addPreferencesFromResource(R.xml.activity_settings);


            // Get widgets :
            _seekBarPref = (SeekBarPreference) this.findPreference("SEEKBAR_VALUE");

            // Set listener :
            getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);

            // Set seekbar summary :
            int radius = PreferenceManager.getDefaultSharedPreferences(this.getActivity()).getInt("SEEKBAR_VALUE", 50);
            _seekBarPref.setSummary(this.getString(R.string.settings_summary).replace("$1", ""+radius));
        }

        @Override
        public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {

            // Set seekbar summary :
            int radius = PreferenceManager.getDefaultSharedPreferences(this.getActivity()).getInt("SEEKBAR_VALUE", 50);
            _seekBarPref.setSummary(this.getString(R.string.settings_summary).replace("$1", ""+radius));
        }
    }
}

布局>activity_main.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/textview_text" />

</RelativeLayout>

菜单> main.xml:

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

    <item
        android:id="@+id/menu_settings"
        android:title="@string/menu_settings"
        android:icon="@android:drawable/ic_menu_preferences"/>

</menu>

xml > Activity 设置.xml:

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >

        <fr.at.testsliderpref.utils.SeekBarPreference
            android:defaultValue="50"
            android:dialogMessage="@string/settings_dialog_message"
            android:key="SEEKBAR_VALUE"
            android:max="100"
            android:summary="@string/settings_summary"
            android:text="@string/settings_unit"
            android:title="@string/settings_title" />

</PreferenceScreen>

值 > strings.xml :

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">TestSliderPref</string>
    <string name="textview_text">SeekBarPreference test</string>

    <string name="menu_settings">Settings</string>
    <string name="settings_dialog_message">Here comes a message</string>
    <string name="settings_summary">Current value is $1</string>
    <string name="settings_unit">Km</string>
    <string name="settings_title">Here comes the title</string>

</resources>

别忘了将你的 SettingsActivity 添加到 list 中，应该没问题。