问题
I try to change background color of a button in item of my listView, but when I try to change the background, the background change each 9 items. When I try to change the orientation of my phone, the background change each 5 items...
---IMAGE TO UNDERSTAND:
http://image.noelshack.com/fichiers/2014/09/1393436440-problem.png
I don't understand, is so strange.
I have an Adapter created.
Java.java (Not my adapter file)
public void clickPresent(View v)
{
v.setBackgroundColor(Color.BLUE);
}
public void drawStudentsInListView()
{
for (int i = 0; i < this.listStudents.size(); i++)
{
Log.e("STUDENT", this.listStudents.get(i)._firstName);
}
if (listStudents.size() > 0)
{
Student[] weather_data;
weather_data = new Student[listStudents.size()];
for (int i = 0; i < listStudents.size(); i++)
{
weather_data[i] = new Student(listStudents.get(i)._firstName, listStudents.get(i)._lastName);
Log.e("Count nbr student: ", "i = " + i);
}
WeatherAdapter adapter = new WeatherAdapter(this, R.layout.listview_item_row, weather_data);
listView1 = (ListView)findViewById(R.id.listView1);
listView1.setAdapter(adapter);
}
}
listview_item_row.xml
<Button
android:layout_width="100dp"
android:layout_height="30dp"
android:background="#009857"
android:layout_marginLeft="10dp"
android:textColor="#ffffff"
android:text="OK"
android:id="@+id/buttonPresent"
android:onClick="clickPresent" />
Adapter.java
public class WeatherAdapter extends ArrayAdapter<Student>
{
Context context;
int layoutResourceId;
Student data[] = null;
public WeatherAdapter(Context context, int layoutResourceId, Student[] data)
{
super(context, layoutResourceId, data);
this.layoutResourceId = layoutResourceId;
this.context = context;
this.data = data;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
View row = convertView;
WeatherHolder holder = null;
if (row == null)
{
LayoutInflater inflater = ((Activity)context).getLayoutInflater();
row = inflater.inflate(layoutResourceId, parent, false);
holder = new WeatherHolder();
holder.firstName = (TextView)row.findViewById(R.id.textFirstName);
holder.lastName = (TextView)row.findViewById(R.id.textLastName);
row.setTag(holder);
}
else
{
holder = (WeatherHolder)row.getTag();
}
Student weather = data[position];
holder.firstName.setText(weather._firstName);
holder.lastName.setText(weather._lastName);
return row;
}
static class WeatherHolder
{
TextView firstName;
TextView lastName;
}
}
I don't understand what the problem is :/
Thanks,
回答1:
To improve performance, ListView uses old views to inflate new ones when you scroll, that's why you see a repeated action in other ones.
To fix your problem, i recommand you to set a boolean variable as Tag for the current item button.
Given that, your row item contains (firstName, lastname), add a new attribut Button like that.
static class WeatherHolder
{
TextView firstName;
TextView lastName;
Button button
}
init it at your GetView as you do for other items, and then when you retreive Student details, Check if the button has a tag equals to True (=> that means already clicked) And in your clickPresent method just set a True tag when you click and False when you unclick.
NB: if tag equals false reset the color.
public void clickPresent(View v)
{
v.setBackgroundColor(Color.BLUE);
v.setTag(true);
}
来源:https://stackoverflow.com/questions/22049108/bug-listview-item-button-onclick-change-background-color-of-parent