Question

大家好我在我的应用程序中使用viewpager，在页面上有一个imageview。在这个图像视图上我设置了onclick监听器。当我要点击此imageview并更改其上的图像时，下一页的图像将被更改，当前页面图像保持不变。如何仅更改当前页面的图像。

这是我的代码。

public class KahawateViewPager extends android.support.v4.view.PagerAdapter{
Context kahawateViewPagerContext;

ImageView kahawateLikeUnlike_ImageView;
TextView kahawateIdiom_TextView;
TextView kahawateIdiomCountry_TextView;

LayoutInflater kahawateViewPagerLayout_LayoutInflater;

public KahawateViewPager(Context context)
{
    this.kahawateViewPagerContext = context;

}

@Override
public int getCount()
{
    //set page count only for testing
    return 10;
}

 @Override
public Object instantiateItem(ViewGroup container, final int position)
{
    kahawateViewPagerLayout_LayoutInflater = (LayoutInflater) kahawateViewPagerContext.getSystemService(kahawateViewPagerContext.LAYOUT_INFLATER_SERVICE);

    final View itemView = kahawateViewPagerLayout_LayoutInflater.inflate(R.layout.kahawate_viewpager_layout, container, false);

    kahawateIdiom_TextView = (TextView) itemView.findViewById(R.id.textview_idieom);

    kahawateIdiomCountry_TextView = (TextView) itemView.findViewById(R.id.textview_ideiomCountry);

    kahawateLikeUnlike_ImageView = (ImageView) itemView.findViewById(R.id.imageView_favourite);

    setKahawateData(position);

    kahawateLikeUnlike_ImageView.setOnClickListener(new View.OnClickListener()
    {

        @Override
        public void onClick(View v)
        {
            Toast.makeText(kahawateViewPagerContext,"Current Position"+position,Toast.LENGTH_LONG).show();
            if(kahawateLikeUnlike_ImageView.getTag().equals("like"))
            {

                kahawateLikeUnlike_ImageView.setImageResource(R.drawable.unlike);
                kahawateLikeUnlike_ImageView.setTag("unlike");
            } else
            {
                kahawateLikeUnlike_ImageView.setImageResource(R.drawable.like);
                kahawateLikeUnlike_ImageView.setTag("like");
            }
        }
        //}
    });

            ((ViewPager) container).addView(itemView);


    return itemView;
}


@Override
public boolean isViewFromObject(View view, Object object)
{
    return view == ((LinearLayout)object);
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    // Remove viewpager_item.xml from ViewPager
    ((ViewPager) container).removeView((LinearLayout) object);

}
void setKahawateData(int ID)
{       
        //setdefault image only for testing 
        kahawateLikeUnlike_ImageView.setImageResource(R.drawable.like);
        kahawateLikeUnlike_ImageView.setTag("like");

}

@Override
public int getItemPosition(Object object) {
    return POSITION_NONE;
}

}

这是我的xml文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:ads="http://schemas.android.com/apk/res-auto"
          xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:orientation="vertical"
          android:background="#f4e9cd">
<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="right"
    android:layout_weight="1"
    android:gravity="right"
    android:orientation="horizontal">

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/imageView_favourite"
        android:layout_gravity="right"
        android:src="@drawable/unlike"
        android:clickable="true"/>

</LinearLayout>

<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_weight="9"
    android:orientation="vertical"
    android:paddingLeft="5dp"
    android:paddingRight="5dp">


    <TextView
        android:id="@+id/textview_idieom"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center|center_vertical"
        android:layout_weight="8"
        android:gravity="center"
        android:text="Big Data"
        />

    <TextView
        android:id="@+id/textview_ideiomCountry"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:layout_weight="2"
        android:gravity="right"
        android:text="Small Data"
        android:paddingRight="5dp"/>
</LinearLayout>

这里是屏幕我要设置/重置的星形图像

此处吐司当前位置0正在显示，但是当我点击位置1页面imageview得到设置。如果我点击第1页图像第2页imageview得到设置等等。

如何设置/重置当前页面imageview？

Answer 1

尝试实现这样的getItemPosition方法：

@Override
public int getItemPosition(Object object) {
    return mDataSource.indexOf(object);
}

通过这种方式，您可以正确获取每个项目的位置

Answer 2

我认为你必须设置viewpager.setOffsetLimit（totalnumberofpage）; 其中totalnumberofpage是列表的数量

第二件事是制作ViewHolder类

private class ViewHolder {
TextView textViewItem;}

并像这样使用它：

@Override

public View getView（int position，View convertView，ViewGroup parent）{

ViewHolderItem viewHolder;


  // The convertView argument is essentially a "ScrapView" as described is Lucas post 
  // http://lucasr.org/2012/04/05/performance-tips-for-androids-listview/
  // It will have a non-null value when ListView is asking you recycle the row layout. 
  // So, when convertView is not null, you should simply update its contents instead of inflating a new row    layout.

if(convertView==null){

    // inflate the layout
    LayoutInflater inflater = ((Activity) mContext).getLayoutInflater();
    convertView = inflater.inflate(layoutResourceId, parent, false);

    // well set up the ViewHolder
    viewHolder = new ViewHolderItem();
    viewHolder.textViewItem = (TextView) convertView.findViewById(R.id.textViewItem);

    // store the holder with the view.
    convertView.setTag(viewHolder);

}else{
    // we've just avoided calling findViewById() on resource everytime
    // just use the viewHolder
    viewHolder = (ViewHolderItem) convertView.getTag();
}

// object item based on the position
ObjectItem objectItem = data[position];

// assign values if the object is not null
if(objectItem != null) {
    // get the TextView from the ViewHolder and then set the text (item name) and tag (item ID) values
    viewHolder.textViewItem.setText(objectItem.itemName);
    viewHolder.textViewItem.setTag(objectItem.itemId);
}

return convertView;}

在viewpager中设置当前页面的imageview onclick

2 个答案: