Question

我正在使用base.i在列表视图中成功地调整了我的适配器。但我有两个问题。在基本适配器的行xml包含imageview，在这个imageview中我想按位置更改背景图像（使用getTag）这是我的来源 BaseAdapter

public class DealBoxXmlAdapterByPosition extends BaseAdapter {
Activity activity;
int layoutResourceId;
private MyCustomImageLoader ILoader;
UserHolder holder = null;

private ArrayList<DealBoxXmlComponentsByPosition> myadapter;

public DealBoxXmlAdapterByPosition(Activity act, int layoutResourceId,
        ArrayList<DealBoxXmlComponentsByPosition> data) {

    this.layoutResourceId = layoutResourceId;
    this.activity = act;
    this.myadapter = data;
    ILoader = new MyCustomImageLoader(act.getApplicationContext());
    notifyDataSetChanged();
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    View row = convertView;

    if (row == null) {
        LayoutInflater inflater = LayoutInflater.from(activity);
        holder = new UserHolder();
        row = inflater.inflate(layoutResourceId, parent, false);

        holder.mainpageadapterimg = (ImageView) row
                .findViewById(R.id.mainpageadapterimg);
        holder.listvieaddtuchart = (ImageView) row
                .findViewById(R.id.listvieaddtuchart);

        holder.EndDate = (TextView) row.findViewById(R.id.EndDate);
        holder.OriginalPrice = (TextView) row
                .findViewById(R.id.OriginalPrice);

        row.setTag(holder);
    } else {
        holder = (UserHolder) row.getTag();
    }

    ILoader.DisplayImage(myadapter.get(position).getKEY_Image(),
            holder.mainpageadapterimg);

    holder.OriginalPrice.setText(myadapter.get(position)
            .getKEY_OriginalPrice() + " ლ");

    holder.EndDate.setText(myadapter.get(position).getKEY_EndDate());

    return row;

}

@Override
public int getCount() {

    return myadapter.size();
}

@Override
public Object getItem(int position) {

    return myadapter.get(position);
}

@Override
public long getItemId(int position) {

    return 0;
}

public void removeObject(int position) {

    this.myadapter.remove(position);

}

public static class UserHolder {

    public TextView OriginalPrice, EndDate;
    public ImageView mainpageadapterimg, listvieaddtuchart;

}

}

这是我的列表视图的onclicklistener方法

private UserHolder holder;
holder = new UserHolder();
holder.listvieaddtuchart
                    .setOnClickListener(new OnClickListener() {

                        @Override
                        public void onClick(View v) {
                            Toast.makeText(getActivity(), "Hello",
                                    Toast.LENGTH_SHORT).show();

                            holder.listvieaddtuchart
                                    .setBackgroundResource(R.drawable.ic_launcher);

                            if (holder.listvieaddtuchart.getDrawable().getConstantState() == getResources().getDrawable( R.drawable.ic_launcher).getConstantState()) 
                            {
                              Toast.makeText(getActivity(), "Image is ic_launcher", Toast.LENGTH_LONG).show(); 
                              // new RegisterAsyntaskNew().execute(); 
                            } 
                          else 
                            {
                             Toast.makeText(getActivity(), "Image isn't ic_launcher", Toast.LENGTH_LONG).show(); 
                             // new RegisterAsyntask().execute(); 
                            }

                        }
                    });

正如我所说，我有两个问题首先，我评论了这一部分

    if (holder.listvieaddtuchart.getDrawable().getConstantState() == getResources().getDrawable( R.drawable.ic_launcher).getConstantState()) 
                            {
                              Toast.makeText(getActivity(), "Image is ic_launcher", Toast.LENGTH_LONG).show(); 
                              // new RegisterAsyntaskNew().execute(); 
                            } 
                          else 
                            {
                             Toast.makeText(getActivity(), "Image isn't ic_launcher", Toast.LENGTH_LONG).show(); 
                             // new RegisterAsyntask().execute(); 
                            }

                        }
                    });

我只能在第二次点击时更改图像视图的背景。我无法在第一次点击时更改背景

我的第二个问题。我想检查我的图像视图的背景资源。但我有nullpointexception

这是我的基本适配器xml代码

<RelativeLayout 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/relativeLayout1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:background="#ffffff" >

    <ImageView
        android:id="@+id/mainpageadapterimg"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:scaleType="fitXY" />
</RelativeLayout>

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="115dp"
    android:layout_alignParentLeft="true"
    android:layout_below="@+id/relativeLayout1"
    android:background="#ffffff" >

    <TextView
        android:id="@+id/mainpageadaptertitle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/EndDate"
        android:layout_alignLeft="@+id/EndDate"
        android:layout_alignParentTop="true"
        android:layout_marginRight="5dp"
        android:layout_marginTop="5dp"
        android:layout_toLeftOf="@+id/Price"
        android:maxLines="3"
        android:text="TextView"
        android:textColor="#3e3e3e"
        android:textSize="16dp" />
    <TextView
        android:id="@+id/OriginalPrice"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:layout_marginRight="14dp"
        android:text="priceeee"
        android:textColor="#787878"
        android:textSize="16dp" />

    <ImageView
        android:id="@+id/listvieaddtuchart"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignRight="@+id/OriginalPrice"
        android:layout_marginBottom="3dp"
        android:src="@drawable/mainpageadapterchartimg" />

    <TextView
        android:id="@+id/EndDate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/imageView2"
        android:layout_alignParentBottom="true"
        android:layout_marginLeft="20dp"
        android:layout_marginBottom="5dp"
        android:text="TextView"
        android:textColor="#3e3e3e"
        android:textSize="16dp" />
    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_marginBottom="7dp"
        android:layout_marginLeft="8dp"
        android:src="@drawable/mainpageclockimage" />

    <TextView
        android:id="@+id/Price"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/OriginalPrice"
        android:layout_alignLeft="@+id/OriginalPrice"
        android:layout_marginBottom="5dp"
        android:text="TextView"
        android:textColor="#f0812b"
        android:textSize="16dp" />

</RelativeLayout>

enter image description here

如果有人知道解决方案，请帮助我感谢

Answer 1

就这样做..

 @Override
public View getView(final int position, View convertView, ViewGroup          parent) {
View row = convertView;

if (row == null) {
    LayoutInflater inflater = LayoutInflater.from(activity);
    holder = new UserHolder();
    row = inflater.inflate(layoutResourceId, parent, false);

    holder.mainpageadapterimg = (ImageView) row
            .findViewById(R.id.mainpageadapterimg);
    holder.listvieaddtuchart = (ImageView) row
            .findViewById(R.id.listvieaddtuchart);

    holder.EndDate = (TextView) row.findViewById(R.id.EndDate);
    holder.OriginalPrice = (TextView) row
            .findViewById(R.id.OriginalPrice);

    row.setTag(holder);
} else {
    holder = (UserHolder) row.getTag();
}

    ILoader.DisplayImage(myadapter.get(position).getKEY_Image(),
        holder.mainpageadapterimg);

    holder.listvieaddtuchart
                .setOnClickListener(new OnClickListener() {

                    @Override
                    public void onClick(View v) {
                        Toast.makeText(getActivity(), "Hello",
                                Toast.LENGTH_SHORT).show();

                        holder.listvieaddtuchart
                                .setBackgroundResource(R.drawable.ic_launcher);

                        if (holder.listvieaddtuchart.getDrawable().getConstantState() == getResources().getDrawable( R.drawable.ic_launcher).getConstantState()) 
                        {
                          Toast.makeText(getActivity(), "Image is ic_launcher", Toast.LENGTH_LONG).show(); 
                          // new RegisterAsyntaskNew().execute(); 
                        } 
                      else 
                        {
                         Toast.makeText(getActivity(), "Image isn't ic_launcher", Toast.LENGTH_LONG).show(); 
                         // new RegisterAsyntask().execute(); 
                        }

                    }
                });

    holder.OriginalPrice.setText(myadapter.get(position)
        .getKEY_OriginalPrice() + " ლ");

    holder.EndDate.setText(myadapter.get(position).getKEY_EndDate());

return row;

}

在getView（）方法中设置onClickListener，无论convertView是否为null。快乐的编码！ ; d

Answer 2

尝试使用以下代码

holder.listvieaddtuchart
                .setOnClickListener(new OnClickListener() {

                    @Override
                    public void onClick(View v) {
                        Toast.makeText(getActivity(), "Hello",
                                Toast.LENGTH_SHORT).show();
                       ImageView imageView = (ImageView) v;

                        if (imageView.getDrawable().getConstantState() == getResources().getDrawable( R.drawable.ic_launcher).getConstantState()) 
                        {
                          Toast.makeText(getActivity(), "Image is ic_launcher", Toast.LENGTH_LONG).show(); 
                       imageView.setImageResource(R.drawable.img1);
                          // new RegisterAsyntaskNew().execute(); 
                        } 
                      else 
                          {
                         Toast.makeText(getActivity(), "Image isn't ic_launcher", Toast.LENGTH_LONG).show(); 
                       imageView.setImageResource(R.drawable.ic_launcher);
                         // new RegisterAsyntask().execute(); 
                           }

                    }
                });

如果您使用的是android：background =“@ drawable / mainpageadapterchartimg”，请按照以下代码

holder.imageViewIcon.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {


            ImageView imageView = (ImageView) v;



            if (imageView.getBackground().getConstantState() == mContext.getResources().getDrawable(R.drawable.ic_launcher).getConstantState()) {
              imageView.setBackground(mContext.getResources().getDrawable(R.drawable.img1));                                                                   

            }else
             {
                       imageView.setBackground(mContext.getResources().getDrawable(R.drawable.R.drawable.ic_launcher));
             }

        }

    }
    });

imageview onclicklistener中的android listview gettag nullpointexception

2 个答案: