Question

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上面显示的是我使用TextViews和RadioGroup的自定义列表视图。根据项目状态是“待处理”还是“提供”，我更新待处理项目 - TextView（红色，顶部）。一切都按预期工作，我能够在滚动时保留RadioGroup选择。

但是，当我滚动时，挂起的项目TextView不会保留其值。只要列表滚动，它就会改变。这是我的getView方法。

public View getView(final int position, View convertView, ViewGroup parent) 
{
    System.out.println(" --- position ---"+position+" --- isChecked[position] --- "+isChecked[position]);

    ViewHolder viewHolder = null;
    if(convertView == null)
    {

        convertView = layoutInflater.inflate(R.layout.order_status_listview_row, null);
        viewHolder = new ViewHolder();
        convertView.setTag(viewHolder);
    }
    else
    {
        viewHolder = (ViewHolder)convertView.getTag();
        convertView.setTag(viewHolder);
    }

    viewHolder.itemName = (TextView)convertView.findViewById(R.id.textview_order_status_item_name);
    viewHolder.itemQuantity = (TextView)convertView.findViewById(R.id.textview_order_status_item_quantity);
    viewHolder.radioGroup = (RadioGroup)convertView.findViewById(R.id.radiogroup_order_status_dialog);

//      isUserChanged[position] = false;
    viewHolder.radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() 
    {           
        public void onCheckedChanged(RadioGroup group, int checkedId) 
        {
 //             if(isUserChanged[position])
            {
                switch(checkedId) 
                {
                    case R.id.radiobutton_served:
                         System.out.println(" --- radiobutton_served ---"+" position "+position+" isChecked[position] "+isChecked[position]);
                         count--;
 //                          countView.setText(DataHelper.getAppropriateCountValue(count));
                         isChecked[position] = true;
                         break;

                    case R.id.radiobutton_pending:
                         System.out.println(" --- radiobutton_pending ---"+" position "+position+" isChecked[position] "+isChecked[position]);
                         isChecked[position] = false;
                         count++;
 //                          countView.setText(DataHelper.getAppropriateCountValue(count));
                         break;             
                }
                countView.setText(DataHelper.getAppropriateCountValue(count));

            }
 //             isUserChanged[position] = false;
        }
    });

    viewHolder.radioGroup.setOnClickListener(new OnClickListener() 
    {
        public void onClick(View view) 
        {
 //             isUserChanged[position] = true;
        }
    }); 

    viewHolder.itemName.setText(orderList.get(position).getDishName());
    viewHolder.itemQuantity.setText(orderList.get(position).getDishQuantity());

    // change selection state for item checked when selection for radioButton changes
    if(isChecked[position])
        viewHolder.radioGroup.check(R.id.radiobutton_served);
    else
        viewHolder.radioGroup.check(R.id.radiobutton_pending);

    return convertView;
}

Answer 1

Dya，我做了一个小例子。

我的Activity包含TextView和ListView。 ListView填充了20个对象（RowObject），它们有自己的布局（row.xml）。代码非常简单，因此您可以轻松阅读并理解它。

<强> activity_main.xml中

<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" >

    <TextView
        android:id="@+id/mTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="0" />

    <ListView
        android:id="@+id/mListView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@id/mTextView" >
    </ListView>

</RelativeLayout>

<强> row.xml

<LinearLayout 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" >

    <RadioGroup
        android:id="@+id/mRadioGroup"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <RadioButton
            android:id="@+id/mRadio1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="radio1" />

        <RadioButton
            android:id="@+id/mRadio2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="radio2" />
    </RadioGroup>

</LinearLayout>

<强> RowObject

public class RowObject {

    private int ID;
    private boolean firstChecked; // else second checked

    public RowObject(int iD, boolean firstChecked) {
        super();
        ID = iD;
        this.firstChecked = firstChecked;
    }

    public boolean isFirstChecked() {
        return firstChecked;
    }

    public void setFirstChecked(boolean firstChecked) {
        this.firstChecked = firstChecked;
    }
}

<强> MainActivity

public class MainActivity extends Activity {

    private TextView mCountTextView;
    private ArrayList<RowObject> mSource;

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

        mSource = new ArrayList<RowObject>();
        for (int i = 0; i < 20; i++) {
            mSource.add(new RowObject(i, false));
        }

        mCountTextView = (TextView) findViewById(R.id.mTextView);

        ListView mListView = (ListView) findViewById(R.id.mListView);
        mListView.setAdapter(new RadioButtonAdapter(getApplicationContext(), mSource));
    }

    private class RadioButtonAdapter extends ArrayAdapter<RowObject> {

        class ViewHolder {
            RadioGroup rbGroup;
            RadioButton btn1;
            RadioButton btn2;
        }

        private LayoutInflater mInflater;

        public RadioButtonAdapter(Context context, ArrayList<RowObject> mSource) {
            super(context, R.layout.row, mSource);
            mInflater = LayoutInflater.from(context);
        }

        public View getView(final int position, View convertView, ViewGroup parent) {
            ViewHolder holder;

            if (convertView == null) {
                convertView = mInflater.inflate(R.layout.row, null);

                holder = new ViewHolder();
                holder.rbGroup = (RadioGroup) convertView.findViewById(R.id.mRadioGroup);
                holder.btn1 = (RadioButton) convertView.findViewById(R.id.mRadio1);

                convertView.setTag(holder);
            } else {
                holder = (ViewHolder) convertView.getTag();
            }

            holder.rbGroup.setOnCheckedChangeListener(new OnCheckedChangeListener() {

                public void onCheckedChanged(RadioGroup group, int checkedId) {
                    switch (checkedId) {
                    case R.id.mRadio1:
                        mSource.get(position).setFirstChecked(true);
                        break;

                    case R.id.mRadio2:
                        mSource.get(position).setFirstChecked(false);
                        break;
                    }
                    mCountTextView.setText("There are " + getNumberOfFirstCheckedViews() + " first buttons selected");
                }
            });

            if (mSource.get(position).isFirstChecked()) {
                holder.btn1.setChecked(true);
                holder.btn2.setChecked(false);
            } else {
                holder.btn1.setChecked(false);
                holder.btn2.setChecked(true);
            }

            return convertView;
        }

        private int getNumberOfFirstCheckedViews() {
            int count = 0;
            for (RowObject object : mSource) {
                if (object.isFirstChecked()) {
                    count++;
                }
            }
            return count;
        }
    }
}

Answer 2

我想我明白了。无论何时滚动，都可以使用

更改值或单选按钮

if(isChecked[position])
    viewHolder.radioGroup.check(R.id.radiobutton_served);
else
    viewHolder.radioGroup.check(R.id.radiobutton_pending);

但是你在调用之前设置了一个监听器。所以每次都会调用听众。

请改为尝试：

viewHolder.radioGroup.setOnCheckedChangeListener(null);

if(isChecked[position])
    viewHolder.radioGroup.check(R.id.radiobutton_served);
else
    viewHolder.radioGroup.check(R.id.radiobutton_pending);

viewHolder.radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() 
    {           
        public void onCheckedChanged(RadioGroup group, int checkedId) 
        {
 //             if(isUserChanged[position])
            {
                switch(checkedId) 
                {
                    case R.id.radiobutton_served:
                         System.out.println(" --- radiobutton_served ---"+" position "+position+" isChecked[position] "+isChecked[position]);
                         count--;
 //                          countView.setText(DataHelper.getAppropriateCountValue(count));
                         isChecked[position] = true;
                         break;

                    case R.id.radiobutton_pending:
                         System.out.println(" --- radiobutton_pending ---"+" position "+position+" isChecked[position] "+isChecked[position]);
                         isChecked[position] = false;
                         count++;
 //                          countView.setText(DataHelper.getAppropriateCountValue(count));
                         break;             
                }
                countView.setText(DataHelper.getAppropriateCountValue(count));

            }
 //             isUserChanged[position] = false;
        }
    });

希望这会对你有所帮助。

ListView与每一行中的RadioGroup

2 个答案: