问题
I have a ListView, which is in singleChoice mode. All I want is to display a RadioButton to the side, that when clicked highlights to say it is selected, and when a different one is clicked that one goes back to unselected and the new one becomes selected. Why is this so hard? This should not be this complicated. I've spent DAYS looking for an appropriate answer to this and I have found nothing, so I'm asking hopefully in a clear and concise manner.
My layout for the listview (R.layout.view_orders):
<?xml version="1.0" encoding="utf-8"?>
<ListView
android:choiceMode="singleChoice"
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:divider="@drawable/list_divider"
android:dividerHeight="1px"
android:focusable="false"
android:focusableInTouchMode="false"
android:cacheColorHint="#00000000">
</ListView>
My custom row (R.layout.orders_row):
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:app="http://schemas.android.com/apk/res/com.xxx.xxxxxx"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="6dip">
<com.xxx.xxxxxx.VerticalLabelView
app:text="SHORT"
app:textColor="#666"
app:textSize="14sp"
android:id="@+id/state"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true" />
<TextView
android:id="@+id/quantity"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@id/state"
android:layout_centerVertical="true"
android:gravity="center"
android:textSize="40sp"
android:layout_margin="2dip"
android:minWidth="30dip"
android:textColor="#555" />
<RelativeLayout
android:layout_toRightOf="@id/quantity"
android:layout_centerVertical="true"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/instrument"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="20sp"
android:textColor="#333"
android:layout_marginLeft="2dip"
android:layout_marginRight="2dip"
/>
<TextView
android:id="@+id/deets"
android:layout_below="@id/instrument"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="16sp"
android:textColor="#888"
android:layout_marginLeft="2dip"
android:layout_marginRight="2dip"
/>
</RelativeLayout>
<RadioButton
android:id="@+id/selector"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
/>
</RelativeLayout>
My onCreate() method:
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.view_orders);
client = new Client(handler);
ola = new OrdersAdapter(this, R.layout.orders_row, Orders);
setListAdapter(ola);
final RelativeLayout loading = (RelativeLayout) findViewById(R.id.loading);
panel = (PositionsPanel) findViewById(R.id.panel);
Utility.showProgressBar(loading);
client.Connect("orders");
}
Now everything underlying works as expected, you click on a radiobutton and through it's tag I can appropriately select that item from the list and manipulate it how I want. However, when the first radio button is clicked, the last one will be selected. Click that same radio button again, and it is now selected as well. Click it once more and nothing happens, both the last and the first are selected. Now I click any other one on the list, it gets selected like expected. Click anyone of the selected radio buttons and nothing happens, the radio button remains selected.
I have tried using the following in onCreate():
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.view_orders);
client = new Client(handler);
ola = new OrdersAdapter(this, android.R.layout.simple_list_item_single_choice, Orders);
setListAdapter(ola);
final RelativeLayout loading = (RelativeLayout) findViewById(R.id.loading);
panel = (PositionsPanel) findViewById(R.id.panel);
Utility.showProgressBar(loading);
client.Connect("orders");
}
and that just shows no radio buttons at all. AWESOME.
Now maybe (read: most likely), I'm just dense and can't figure this out, but I've seen this question asked a lot with no real answer. Lots of references to other tutorials or to the Commonsware guy's book. However, the comments are old now and his repository has changed so much, that those are no longer correct answers.
So, does anyone have any idea how to get the expected functionality out of this? Or failing that, just pass me along the GMail app's source code. :)
回答1:
Do bear in mind that in the ListView row items are RECYCLED. This is likely to explain why actions on one row are affecting another. Dig around in Mark's book and you'll find coverage of this.
If you're using an adapter with the list, you can use getView() on an adapter to add a click handler to each row as it's created/recycled, and make sure the state is managed correctly as the row items are created and recycled.
My approach is to store the state in my own data structure, and then use getView() to mirror that in the UI as the user scrolls up and down the ListView. There may be a better solution, but that works for me.
回答2:
Simple solution:
Add this line in the RadioButton layout of your xml file:
<RadioButton
...
android:onClick="onClickRadioButton"
...
/>
Then in the activity class that uses the ListView, add the following:
private RadioButton listRadioButton = null;
int listIndex = -1;
public void onClickRadioButton(View v) {
View vMain = ((View) v.getParent());
// getParent() must be added 'n' times,
// where 'n' is the number of RadioButtons' nested parents
// in your case is one.
// uncheck previous checked button.
if (listRadioButton != null) listRadioButton.setChecked(false);
// assign to the variable the new one
listRadioButton = (RadioButton) v;
// find if the new one is checked or not, and set "listIndex"
if (listRadioButton.isChecked()) {
listIndex = ((ViewGroup) vMain.getParent()).indexOfChild(vMain);
} else {
listRadioButton = null;
listIndex = -1;
}
}
With this simple code only one RadioButton is checked. If you touch the one that is already checked, then it returns to the unchecked mode.
"listIndex" is tracking the checked item, -1 if none.
If you want to keep always one checked, then code in onClickRadioButton should be:
public void onClickRadioButton(View v) {
View vMain = ((View) v.getParent());
int newIndex = ((ViewGroup) vMain.getParent()).indexOfChild(vMain);
if (listIndex == newIndex) return;
if (listRadioButton != null) {
listRadioButton.setChecked(false);
}
listRadioButton = (RadioButton) v;
listIndex = newIndex;
}
回答3:
My Name Is Gourab Singha. I solved This Issue. I have Written This Code to solve it. I hope this helps you all. Thanks. I require 3 hours for this.
public void add_option_to_list(View v){
LinearLayout ll = (LinearLayout)v.getParent();
LinearLayout ll_helper = null;
LinearLayout ll2 = (LinearLayout)ll.getParent();
LinearLayout ll3 = (LinearLayout)ll2.getParent();
ListView ll4 = (ListView)ll3.getParent();
//RadioButton rb1= (RadioButton)ll.getChildAt(1);
Toast.makeText(getApplicationContext(), ", "+ll4.getChildCount(), Toast.LENGTH_LONG).show();
//ll.findViewById(R.id.radio_option_button)
for(int k=0;k<ll4.getChildCount();k++){
ll3 = (LinearLayout)ll4.getChildAt(k);
ll2 = (LinearLayout)ll3.getChildAt(0);
ll_helper = (LinearLayout)ll2.getChildAt(0);
RadioButton rb1 = (RadioButton)ll_helper.getChildAt(1);
if(rb1.isChecked())
rb1.setChecked(false);
}
RadioButton rb1 = (RadioButton)ll.getChildAt(1);
rb1.setChecked(true);
//Toast.makeText(getApplicationContext(), ""+((TextView)ll.getChildAt(4)).getText().toString(), Toast.LENGTH_LONG).show();
}
The XML:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="@+id/id"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Category Name"
android:textAppearance="?android:attr/textAppearanceMedium"
android:visibility="gone" />
<RadioButton
android:id="@+id/radio_option_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="add_option_to_list"
android:text="" />
<TextView
android:id="@+id/option_name"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_marginLeft="3dp"
android:layout_weight="5.35"
android:text="Category Name"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/option_price"
android:layout_width="76dp"
android:layout_height="wrap_content"
android:layout_marginRight="10dp"
android:gravity="right"
android:text="$0.00"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="@+id/option_unit_price"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginRight="5dp"
android:gravity="right"
android:text="$0.00"
android:textAppearance="?android:attr/textAppearanceMedium"
android:visibility="gone" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
回答4:
I've just had a similar problem. It seemed that it was related to views recycling. But I added Log's everywhere and noticed that the recycling handling was fine. The problem was RadioButtons handling. I was using:
if(answer == DBAdapter.YES){
rbYes.setChecked(true);
rbNo.setChecked(false);
}
else if(answer == DBAdapter.NO){
rbYes.setChecked(false);
rbNo.setChecked(true);
}
else{
rbYes.setChecked(false);
rbNo.setChecked(false);
}
and the correct way of doing it is:
if(answer == DBAdapter.YES){
rbYes.setChecked(true);
}
else if(answer == DBAdapter.NO){
rbNo.setChecked(true);
}
else{
RadioGroup rg = (RadioGroup)(holder.answerView);
rg.clearCheck();
}
回答5:
You can achieve much more simple, follow this. It was tried in MarshMallow
1)Have a CheckedTextView :
<CheckedTextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/text1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:checkMark="?android:attr/listChoiceIndicatorSingle"
android:padding="10dp"
android:textAppearance="?android:attr/textAppearanceMedium">
ListChoiceIndicatorSinglewill displayRadioButton.ListChoiceIndicatorMultiplewill displayCheckBox
Don't forgot to put choiceMode:Single in your ListView.
回答6:
Inside the adapter
viewHolder.radioBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.e("called", "called");
if(position != mSelectedPosition && mSelectedRB != null){
mSelectedRB.setChecked(false);
}
mSelectedPosition = position;
mSelectedRB = (RadioButton)v;
}
});
viewHolder.radioBtn.setText(mList[position]);
if(mSelectedPosition != position){
viewHolder.radioBtn.setChecked(false);
}else{
viewHolder.radioBtn.setChecked(true);
if(mSelectedRB != null && viewHolder.radioBtn != mSelectedRB){
mSelectedRB = viewHolder.radioBtn;
}
}
add style to the radio button
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/tick" android:state_checked="true"/>
<item android:drawable="@drawable/untick" android:state_checked="false"/>
</selector>
and in the xml use the radio button style
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<RadioButton
android:id="@+id/radioBtn"
android:layout_width="match_parent"
android:layout_height="50dp"
android:button="@null"
android:checked="true"
android:drawablePadding="30dp"
android:drawableRight="@drawable/checkmark"
android:text="first" />
</RelativeLayout>
回答7:
On your adapter:
public void setChecked(View v, int position) {
ViewGroup parent = ((ViewGroup) v.getParent()); // linear layout
for (int x = 0; x < parent.getChildCount() ; x++) {
View cv = parent.getChildAt(x);
((RadioButton)cv.findViewById(R.id.checkbox)).setChecked(false); // your checkbox/radiobtt id
}
RadioButton radio = (RadioButton)v.findViewById(R.id.checkbox);
radio.setChecked(true);
}
On your activity/fragment:
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
((ModelNameAdapter)adapter).setChecked(view, position);
}
});
来源：https://stackoverflow.com/questions/4250599/android-listview-with-radiobutton-in-singlechoice-mode-and-a-custom-row-layout