Multiple choice/single choice for listview

The listview itself has a single-choice and multi-choice mode. You can set it through listview. setchoicemode:

Listview. setchoicemode (listview. choice_mode_multiple); // enable multi-choice listview. setchoicemode (listview. choice_mode_single); // enables single-choice listview. setchoicemode (listview. choice_mode_none); // default mode listview. setchoicemode (listview. choice_mode_multiple_modal); // I have never used it. I don't know what it is.

Single choiceRequired: listview. setchoicemode (listview. choice_mode_single );
The listview control also needs to specify a selector: Android: listselector = "@ drawable/checkable_item_selector"

<selector xmlns:android="http://schemas.android.com/apk/res/android">    <item android:drawable="@color/c1" android:state_pressed="true"/>    <item android:drawable="@color/c1" android:state_checked="true"/>    <item android:drawable="@color/c2"/></selector>

However, the selected color is the system-selected color instead of the specified C1. Why?
Implement multiple choiceSettings: listview. setchoicemode (listview. choice_mode_single );
You need to implement the checkable interface for the view of each item. The following is the checkable interface implemented by linearlayout:

Public class extends linearlayout implements checkable {private Boolean mchecked; Public checkablelinearlayout (context, attributeset attrs) {super (context, attrs) ;}@ override public void setchecked (Boolean checked) {mchecked = checked; setbackgrounddrawable (checked? New colordrawable (0xff1_a0): NULL); // blue when elected} @ override public Boolean ischecked () {return mchecked;} @ override public void toggle () {setchecked (! Mchecked );}}

Use:

<com.ljfbest.temp.CheckableLinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content">    <TextView        android:id="@+id/tv"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:gravity="center_vertical"        android:minHeight="?android:attr/listPreferredItemHeightSmall"        android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"        android:paddingStart="?android:attr/listPreferredItemPaddingStart"        android:textAppearance="?android:attr/textAppearanceListItemSmall" /></com.ljfbest.temp.CheckableLinearLayout> 

The demo diagram is attached as follows:

The following are several APIs for obtaining/setting information about the selected entries: listview. getcheckeditemcount (); // get the selected number of rows: the value of choice_mode_none is invalid. listview. getcheckeditemposition (); // gets the selected row. The value is valid only in single-choice mode and intlistview is returned. getcheckeditemids (); // obtain the IDs of the selected items, which is of the long [] type. Note that the hasstableids () of the adapter returns true, and these IDs are the getitemid (INT position) of the adapter) returned. the demo shows the listview. setitemchecked (Position, value); // you can specify the status of a row.


In addition, the following error may be reported when listview is used:Java. Lang. classcastexception: Android. widget. headerviewlistadapter cannot be cast to Android. widget. simpleadapterlistview has headerview/footerview, and its original adapter will be encapsulated into headerviewlistadapter:

Listadapter used when a listview has header views. this listadapter wraps another one and also keeps track of the header views and their associated data objects. this is intended as a base class; you will probably not need to use this class directly in your own code.

You can obtain the original adapter in the following ways: headerviewlistadapter hadapter = (headerviewlistadapter) listview. getadapter (); myadapter my = (myadapter) hadapter. getwrappedadapter ();
Therefore, when a header/footer is added, lv_data.getadapter ()). getwrappedadapter (). getcount () and (headerviewlistadapter) listview. getadapter ()). getwrappedadapter (). getcount () is 1 different
Demo address:Http://download.csdn.net/detail/ljfbest/8109731

Multiple choice/single choice for listview