【发布时间】：2016-12-15 07:20:57
【问题描述】：
如何更改 Seekbar 进度更改时的 ListView 项目值。
<?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">
<SeekBar
android:id="@+id/seekValue"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="20dp"
android:max="100" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_margin="10dp">
<ListView
android:id="@+id/listSelector"
android:layout_width="fill_parent"
android:layout_height="fill_parent"></ListView>
</LinearLayout>
</LinearLayout>
和 ListView 项目是：
<?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">
<RelativeLayout
android:id="@+id/layoutSelector"
android:layout_width="fill_parent"
android:layout_height="50dp"
android:background="@android:color/darker_gray">
<TextView
android:id="@+id/txtItemName"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_toLeftOf="@+id/txtValueChanges"
android:padding="5dp"
android:text="Item Name"
android:textAppearance="?android:textAppearanceLarge"
android:textStyle="bold" />
<TextView
android:id="@+id/txtValueChanges"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:padding="5dp"
android:visibility="gone"
android:text="0"
android:textAppearance="?android:textAppearanceMedium"
android:textStyle="bold" />
</RelativeLayout>
</LinearLayout>
现在这是我的 mailActivity 类的样子：
public class ListActivitys extends Activity {
ArrayList listItemName;
public static ListView listSelector;
SeekBar seekValue;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
listItemName = new ArrayList();
for (int i = 0; i < 50; i++) {
listItemName.add("Item : " + (i + 1));
}
seekValue = (SeekBar) findViewById(R.id.seekValue);
listSelector = (ListView) findViewById(R.id.listSelector);
listSelector.setAdapter(new AdapterList(ListActivitys.this, listItemName,seekValue));
}
}
最后我的自定义适配器是：
public class AdapterList extends BaseAdapter {
Context mcContext;
ArrayList listItems, TempListItems;
int selectedPos = 0;
SeekBar seekValue;
public AdapterList(Context listActivitys, ArrayList listItemName, SeekBar seek) {
listItems = listItemName;
mcContext = listActivitys;
seekValue = seek;
createATemList(listItemName.size());
}
private void createATemList(int size) {
TempListItems = new ArrayList();
for (int i=0; i<size; i++){
TempListItems.add("0");
}
}
@Override
public int getCount() {
return listItems.size();
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
LayoutInflater mInflater = (LayoutInflater) mcContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null) {
convertView = mInflater.inflate(R.layout.adapter_list_item, null);
holder = new ViewHolder();
holder.txtItemName = (TextView) convertView.findViewById(R.id.txtItemName);
holder.txtValueChanges = (TextView) convertView.findViewById(R.id.txtValueChanges);
holder.layoutSelector = (RelativeLayout) convertView.findViewById(R.id.layoutSelector);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
if (selectedPos == position) {
holder.layoutSelector.setBackgroundColor(mcContext.getResources().getColor(R.color.colorAccent));
} else {
holder.layoutSelector.setBackgroundColor(mcContext.getResources().getColor(R.color.transparent));
}
if (!TempListItems.get(selectedPos).equals("0")){
holder.txtValueChanges.setVisibility(View.VISIBLE);
}else{
holder.txtValueChanges.setVisibility(View.GONE);
}
holder.txtItemName.setText(listItems.get(position).toString());
holder.layoutSelector.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
selectedPos = position;
notifyDataSetChanged();
}
});
seekValue.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
/*View view = (View) seekBar.getParent();
if(view != null){
TextView tvProgress = (TextView)view.findViewById(R.id.txtValueChanges);
tvProgress.setVisibility(View.VISIBLE);
tvProgress.setText(progress + "%");
}*/
updateView(selectedPos, progress);
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
return convertView;
}
private void updateView(int selectedPos, int progress) {
View v = ListActivitys.listSelector.getChildAt(selectedPos -
ListActivitys.listSelector.getFirstVisiblePosition());
if (v == null)
return;
TextView txtValueChanges = (TextView) v.findViewById(R.id.txtValueChanges);
TempListItems.set(selectedPos,progress+"");
if (!TempListItems.get(selectedPos).equals("0")){
System.out.println("=== Progress : " + progress);
txtValueChanges.setText(TempListItems.get(selectedPos)+"");
notifyDataSetChanged();
}
}
private class ViewHolder {
TextView txtValueChanges;
TextView txtItemName;
RelativeLayout layoutSelector;
}
}
当 Seekbar 值改变时是否可以改变 ListView 项的值。如果是，那怎么办？请帮帮我。
谢谢。
【问题讨论】：
-
当seekbar改变时，
ListView中的哪一项你想改变？ -
我想从 ListView 中更改选中的项目，这就是为什么我在点击 layoutSelector 时保持选中的项目位置，并在 ListView 的 txtValueChanges 项目中显示 seekbar 的值。
-
可以，带有标志。当标志改变（在搜索栏改变）时，只需通知适配器。根据 getView() 中的这个标志更改选择的 ui