实现MultiSelectListPreference 在Android-10

在Android2.3.3 以下的版本遇到一个问题，android api只提供了一个ListPreference单选框， 要实现一个多选的对话框， 有两种方法：

1. 继承 

ListPreference class，实现MultiSelectListPreference的功能， 然后在xml中引用这个class即可在

 

PreferenceScreen中创建一个多选框。这个sample code网上很多， 这里引用一个，来

 

自 

 

 

http://passwdsafe.hg.sourceforge.net/

 

 

 

import android.app.AlertDialog.Builder; import android.content.Context; import android.content.DialogInterface; import android.preference.ListPreference; import android.util.AttributeSet; /** * @author jharris * Patterned off of class from http://blog.350nice.com/wp/archives/240 */ public class MultiSelectListPreference extends ListPreference { private static final String SEPARATOR = "|"; private boolean[] itsSelectedItems; /** * @param context */ public MultiSelectListPreference(Context context) { this(context, null); } /** * @param context * @param attrs */ public MultiSelectListPreference(Context context, AttributeSet attrs) { super(context, attrs); int len = 0; if (getEntries() != null) { len = getEntries().length; } tsSelectedItems = new boolean[len]; } /* (non-Javadoc) * @see android.preference.ListPreference#setEntries(java.lang.CharSequence[]) */ @Override public void setEntries(CharSequence[] entries) { super.setEntries(entries); int len = 0; if (entries != null) { len = entries.length; } itsSelectedItems = new boolean[len]; } /* (non-Javadoc) * @see android.preference.ListPreference#onPrepareDialogBuilder(android.app.AlertDialog.Builder) */ @Override protected void onPrepareDialogBuilder(Builder builder) { CharSequence[] entries = getEntries(); CharSequence[] entryValues = getEntryValues(); if ((entries == null) || (entryValues == null) || (entries.length != entryValues.length)) { throw new IllegalStateException( "ListPreference requires an entries array and an entryValues " + "array which are both the same length"); } String value = getValue(); String[] values = null; if (value != null) { values = value.split("//Q" + SEPARATOR + "//E"); } for (int entryIdx = 0; entryIdx < entryValues.length; ++entryIdx) { itsSelectedItems[entryIdx] = false; if (values != null) { for (String val : values) { if (entryValues[entryIdx].equals(val)) { itsSelectedItems[entryIdx] = true; break; } } } } builder.setMultiChoiceItems( entries, itsSelectedItems, new DialogInterface.OnMultiChoiceClickListener() { public void onClick(DialogInterface dialog, int which, boolean isChecked) { itsSelectedItems[which] = isChecked; } }); } /* (non-Javadoc) * @see android.preference.ListPreference#onDialogClosed(boolean) */ @Override protected void onDialogClosed(boolean positiveResult) { CharSequence[] entryValues = getEntryValues(); if (positiveResult && (entryValues != null)) { boolean first = true; StringBuilder newValue = new StringBuilder(); for (int i = 0; i < entryValues.length; ++i) { if (itsSelectedItems[i]) { if (first) { first = false; } else { newValue.append(SEPARATOR); } newValue.append(entryValues[i]); } } String newStr = newValue.toString(); if (callChangeListener(newStr)) { setValue(newStr); } } } } 

 

 

2. 用layout实现自己的一个dialog.这种方法要麻烦一点，但是自己可定义的UI会比较灵活。继承的 

 

ListPreference 不好修改一些风格和背景图片。

public class MultiSelectListDialog extends Dialog implements Button.OnClickListener { private Button mButtonCancel; private Button mButtonOk; private Context mContext; private ArrayAdapter<String> mContentsAdapter; private ListView mList; public MultiSelectListDialog(Context context, int theme){ super(context, theme); } public MultiSelectListDialog(Context context) { this(context, R.style.Dialog_Alert); mContext = context; requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.prefernce_dialog); mContentView = onCreateDialogView(); if (mContentView != null) { String[] contents = mContentView.getResources().getStringArray(R.array.multi_select_list); mContentsAdapter = new ArrayAdapter<String>(context, android.R.layout.simple_list_item_multiple_choice, contents); } mList = (ListView)findViewById(R.id.list); mList.setAdapter(mContentsAdapter); mList.setItemsCanFocus(false); mList.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE); mList.setOnItemClickListener(contentsItemListener); mButtonCancel = (Button)findViewById(R.id.Cancel); mButtonCancel.setOnClickListener(ShareContentsDialog.this); mButtonOk = (Button)findViewById(R.id.Ok); mButtonOk.setOnClickListener(ShareContentsDialog.this); } protected View onCreateDialogView() { LayoutInflater inflater = (LayoutInflater) getContext().getSystemService( Context.LAYOUT_INFLATER_SERVICE); return inflater.inflate(R.layout.prefernce_dialog, null); } OnItemClickListener contentsItemListener = new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { for(int i = 0; i <= mContentsAdapter.getCount(); i++ ) { if (i == position) { //Todo check the item click result } } } }; public void onClick(View v) { if(v == mButtonCancel) { //Cancel button has been check down. dismiss(); } else if(v == mButtonOk) { //OK button has been check down. dismiss(); } } } 

layout/prefernce_dialog.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:paddingLeft="0px" android:paddingRight="0px" android:paddingTop="0px" android:paddingBottom="0px" android:orientation="vertical" android:background="@drawable/background" android:layout_height="match_parent"> <!--Top : Title--> <!-- background--> <LinearLayout android:layout_width="fill_parent" android:layout_height="60px" android:paddingLeft="0px" android:paddingRight="0px" android:paddingTop="0px" android:paddingBottom="0px" android:orientation="vertical" android:background="@drawable/bg_title" android:gravity="center_horizontal" > <!-- Icon & Title Text --> <LinearLayout android:layout_width="wrap_content" android:layout_height="fill_parent" android:orientation="horizontal" android:gravity="center_vertical" > <ImageView android:layout_width="32px" android:layout_height="32px" android:src="@drawable/ic_dialog" android:layout_marginRight="5px" /> <TextView android:id="@+id/title" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout> </LinearLayout> <!--Middle : List--> <LinearLayout android:id="@+id/contentPanel" android:layout_width="480px" android:layout_height="wrap_content" android:paddingLeft="0px" android:paddingRight="0px" android:paddingTop="0px" android:paddingBottom="0px" android:layout_weight="1" android:orientation="vertical"> <!-- Contains List --> <ListView android:id="@+id/list" android:background="@null" android:layout_width="fill_parent" android:layout_height="wrap_content" android:paddingLeft="38dip" android:paddingRight="38dip" android:listSelector="@drawable/dialog_list_selector"> </ListView> </LinearLayout> <!--Bottom : Button--> <!-- background --> <LinearLayout android:layout_width="fill_parent" android:layout_height="70px" android:orientation="horizontal" android:paddingLeft="10px" android:paddingRight="10px" android:paddingTop="0px" android:paddingBottom="10px" android:gravity="center" > <!-- Ok Button --> <Button android:id="@+id/buttonOk" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_margin="1px" android:paddingLeft="0px" android:paddingRight="0px" android:paddingTop="1px" android:paddingBottom="1px" android:background="@drawable/dialog_btn" android:textColor="@color/dialog_button_text" android:textSize="19sp" android:textStyle="normal" android:layout_gravity="center" android:visibility="visible" android:layout_weight="1.0" /> <!-- Cancel Button --> <Button android:id="@+id/buttonCancel" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_margin="1px" android:paddingLeft="0px" android:paddingRight="0px" android:paddingTop="1px" android:paddingBottom="1px" android:background="@drawable/dialog_btn" android:textColor="@color/dialog_button_text" android:textSize="19sp" android:textStyle="normal" android:layout_gravity="center" android:visibility="visible" android:layout_weight="1.0" /> </LinearLayout> </LinearLayout>