如何平滑滚动到列表视图中的下一项用户后，点击yes或no单选按钮的单选按钮组。 例如。 如果用户回答是或否的第一个问题应该平滑滚动到第二个问题。 我发现下面的代码，它正在与静态的位置值，但我不知道如何滚动到上选择单选组（是或否单选按钮）的下一个索引（下一个问题）。
int index = 0;
int h1 = simpleListView.getHeight();
int h2 = simpleListView.getHeight();
int duration=500;
simpleListView.smoothScrollToPositionFromTop(index+4, h1/2 - h2/2, duration);
1）MainActivity_.class：-----------------
public class MainActivity_ extends AppCompatActivity {
private ListView lv;
private CustomAdapter customAdapter;
private String[] questions;
private Button submit;
private Button clear;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout8);
questions = new String[10];
for(int i = 0 ; i<10 ; i++){
questions[i] = "Q " + i;
}
lv = (ListView) findViewById(R.id.lv);
customAdapter = new CustomAdapter(getApplicationContext() , questions);
lv.setAdapter(customAdapter);
submit = (Button) findViewById(R.id.submit);
submit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
boolean found_unanswered = false;
int index_first_unanswered = 0;
List<Integer> backgroundColor = new ArrayList<Integer>(); // new
if(customAdapter != null){
for(int i = 0 ; i<customAdapter.getSelectedAnswers().size() ; i++){
if(customAdapter.getSelectedAnswers().get(i).equals("3")){
if(!found_unanswered) { // new
found_unanswered = true;
index_first_unanswered = i; // new
}
backgroundColor.add(Color.RED); // new
}else{ // new
backgroundColor.add(Color.WHITE);
}
}
}
if(!found_unanswered) {
Toast.makeText(getApplicationContext(), "All Answered", Toast.LENGTH_LONG).show();
customAdapter.setBackgroundColor(backgroundColor); // new
//Go to other activity
}else{ // new
Toast.makeText(getApplicationContext(), "Found Unanswered", Toast.LENGTH_LONG).show();
if(customAdapter != null && lv != null){
customAdapter.setBackgroundColor(backgroundColor);
lv.smoothScrollToPosition(index_first_unanswered);
}
}
}
});
clear = (Button) findViewById(R.id.clear);
clear.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (customAdapter != null) {
customAdapter.clearSelectedAnswers();
}
}
});
}
}
2）CustomAdapter.class：----------------
public class CustomAdapter extends BaseAdapter {
Context context;
String[] questionsList;
LayoutInflater inflter;
private List<String> selectedAnswers;
private List<Integer> backgroundColor; // new
public CustomAdapter(Context context, String[] questionsList) {
this.context = context;
this.questionsList = questionsList;
selectedAnswers = new ArrayList<String>();
backgroundColor = new ArrayList<Integer>(); // new
for (int i = 0; i < questionsList.length; i++) {
selectedAnswers.add("3");
backgroundColor.add(Color.WHITE); // new
}
inflter = (LayoutInflater.from(context));
}
@Override
public int getCount() {
return questionsList.length;
}
@Override
public Object getItem(int i) {
return questionsList[i];
}
@Override
public long getItemId(int i) {
return i;
}
@Override
public int getViewTypeCount() {
return questionsList.length;
}
@Override
public int getItemViewType(int i) {
return i;
}
@Override
public View getView(final int i, View convertView, ViewGroup viewGroup) {
View view = convertView;
if (convertView == null) {
if (inflter != null) {
view = inflter.inflate(R.layout.list_items, null);
}
}
TextView question = (TextView) view.findViewById(R.id.question);
question.setText(questionsList[i]);
question.setBackgroundColor(backgroundColor.get(i)); // new
// initialize/re-restore UI Radio Button State
final RadioGroup rg = (RadioGroup) view.findViewById(R.id.radio_group);
RadioButton rb_yes = (RadioButton) rg.findViewById(R.id.yes);
RadioButton rb_no = (RadioButton) rg.findViewById(R.id.no);
if(selectedAnswers.get(i).equals("1")){
rg.check(R.id.yes);
rb_yes.setBackgroundColor(Color.GREEN);
rb_no.setBackgroundColor(Color.GRAY);
}else if(selectedAnswers.get(i).equals("2")){
rg.check(R.id.no);
rb_yes.setBackgroundColor(Color.GRAY);
rb_no.setBackgroundColor(Color.BLACK);
}else {
// no answer.
rg.clearCheck(); // new
rb_yes.setBackgroundColor(Color.GRAY);
rb_no.setBackgroundColor(Color.GRAY);
}
rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
RadioButton rb_yes = (RadioButton) group.findViewById(R.id.yes);
RadioButton rb_no = (RadioButton) group.findViewById(R.id.no);
//Toast.makeText(context , (checkedId == R.id.yes)?"yes":"no" , Toast.LENGTH_LONG).show();
switch (checkedId){
case R.id.yes:
rb_yes.setBackgroundColor(Color.GREEN);
rb_no.setBackgroundColor(Color.GRAY);
selectedAnswers.set(i, "1");
break;
case R.id.no:
rb_yes.setBackgroundColor(Color.GRAY);
rb_no.setBackgroundColor(Color.BLACK);
selectedAnswers.set(i, "2");
break;
default: // new
rb_yes.setBackgroundColor(Color.GRAY);
rb_no.setBackgroundColor(Color.GRAY);
selectedAnswers.set(i, "3");
break;
}
}
});
return view;
}
public List<String> getSelectedAnswers(){
return selectedAnswers;
}
public void clearSelectedAnswers(){
selectedAnswers = new ArrayList<String>();
backgroundColor = new ArrayList<Integer>();
for (int i = 0; i < questionsList.length; i++) {
selectedAnswers.add("3");
backgroundColor.add(Color.WHITE); // new
}
this.notifyDataSetChanged();
}
public void setBackgroundColor(List<Integer> backgroundColor_){ // new
this.backgroundColor = backgroundColor_;
this.notifyDataSetChanged();
}
}
3）layout_8.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:weightSum="100"
android:orientation="vertical">
<ListView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="90"
android:id="@+id/lv">
</ListView>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="70dp"
android:layout_weight="10"
android:layout_marginTop="10dp"
android:layout_marginBottom="10dp"
android:orientation="horizontal">
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Submit"
android:layout_toStartOf="@id/v"
android:textAllCaps="false"
android:id="@+id/submit"/>
<View
android:layout_width="1dp"
android:layout_height="0dp"
android:id="@+id/v"
android:layout_centerInParent="true">
</View>
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Clear"
android:layout_toEndOf="@id/v"
android:textAllCaps="false"
android:id="@+id/clear"/>
</RelativeLayout>
</LinearLayout>
4）list_items.xml：--------
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical">
<!-- TextView for displaying question-->
<TextView
android:id="@+id/question"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:textColor="#000"
android:textSize="30dp"
android:text="Which is your most favorite?"
/>
<FrameLayout 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"
tools:context=".MainActivity"
android:id="@+id/main">
<RadioGroup
android:id="@+id/radio_group"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:orientation="horizontal">
<RadioButton
android:id="@+id/yes"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="20dp"
android:button="@null"
android:paddingHorizontal="30dp"
android:paddingVertical="5dp"
android:text="YES"
android:textSize="50dp" />
<RadioButton
android:id="@+id/no"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="20dp"
android:button="@null"
android:paddingHorizontal="30dp"
android:paddingVertical="5dp"
android:text="NO"
android:textSize="50dp" />
</RadioGroup>
</FrameLayout>
</LinearLayout>
