Bug - ListView - > item - >按钮OnClick:更改父级的背景颜色

时间:2014-02-26 17:42:16

标签: java android android-layout android-listview android-adapter

我尝试更改listView项目中按钮的背景颜色,但是当我尝试更改背景时,背景会更改每9个项目。 当我尝试更改手机的方向时,背景会改变每5个项目......

--- 想要理解的图像:
http://image.noelshack.com/fichiers/2014/09/1393436440-problem.png

我不明白,太奇怪了。

我已创建适配器。

Java.java (不是我的适配器文件)

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;
    }

}

我不明白问题是什么:/

谢谢,

1 个答案:

答案 0 :(得分:1)

为了提高性能,ListView使用旧视图在滚动时为新视图充气,这就是为什么你会在其他视图中看到重复动作的原因。

要解决您的问题,我建议您将布尔变量设置为当前项目按钮的标记。

鉴于此,您的行项包含(firstName,lastname),添加一个新的attribut按钮。

static class WeatherHolder
    {
        TextView firstName;
        TextView lastName;
        Button button
    }

在您的GetView上为其他项目启动它,然后当您检索学生详细信息时,检查该按钮是否有标签等于True(=&gt;表示已经点击) 在clickPresent方法中,只需在单击时设置True标记,在取消选中时设置为False。

注意:如果tag等于false,则重置颜色。

public void clickPresent(View v)
{
    v.setBackgroundColor(Color.BLUE);
    v.setTag(true); 

}