Question

我有一个名为custom _ ListView的自定义布局listview.xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="20dp"
android:padding="5dp"
android:id="@+id/file_name"
/>

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textSize="18dp"
    android:id="@+id/file_path"/>

</LinearLayout>

这是我的CustomAdapter课程：

public class CustomAdapter extends BaseAdapter {

ArrayList<File> result;
Context context;

private static LayoutInflater inflater=null;
public CustomAdapter(Activity parentActivity, ArrayList<File> fileList) {
    // TODO Auto-generated constructor stub
    result=fileList;
    context=parentActivity;
   inflater = ( LayoutInflater )context.
            getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
    // TODO Auto-generated method stub
    return result.size();
}

@Override
public Object getItem(int position) {
    // TODO Auto-generated method stub
    return position;
}

@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;
}

public class Holder
{
    TextView file_name;
    TextView file_path;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub



    if (convertView == null)
    {
        LayoutInflater mInflater =   (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = mInflater.inflate(R.layout.custom_listview, null);
    }

    Holder holder=new Holder();
    holder.file_name=(TextView) convertView.findViewById(R.id.file_name);
    holder.file_path=(TextView) convertView.findViewById(R.id.file_path);
    //holder.img=(ImageView) rowView.findViewById(R.id.imageView1);
    holder.file_name.setText(result.get(position).getName());
    holder.file_path.setText(result.get(position).getPath());

    return convertView;
    }

    }

以下是onClickListener的{{1}}：

ListView

当我点击列表顶部的任何项目时，该应用程序正常工作。但是只要我向下滚动并单击任何项目，应用程序就会崩溃。请帮忙。谢谢！

Answer 1

你忘了别的。试试这个。如果您没有实现其他部分，那么在滚动您的应用时会崩溃。

Holder holder;

    if (convertView == null)
        {
     holder=new Holder();
            LayoutInflater mInflater =   (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = mInflater.inflate(R.layout.custom_listview, null);
     holder.file_name=(TextView) convertView.findViewById(R.id.file_name);
        holder.file_path=(TextView) convertView.findViewById(R.id.file_path);
    convertView.setTag(holder);
        }else{
    holder = (Holder) convertView.getTag();
    }

编辑：如果设置了条件if (convertView == null)并忘记设置其他部分然后recycling（滚动）的时间，它将尝试重新创建并且文本更改所有行都发生在行之间，崩溃等。因此，无论何时在getView中添加if条件，都必须添加if。否则。

Answer 2

不应该;

if (convertView == null)
{
   LayoutInflater mInflater =   (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
   convertView = mInflater.inflate(R.layout.custom_listview, null);

   Holder holder=new Holder();
   holder.file_name=(TextView) convertView.findViewById(R.id.file_name);
   holder.file_path=(TextView) convertView.findViewById(R.id.file_path);
   //holder.img=(ImageView) rowView.findViewById(R.id.imageView1);
   holder.file_name.setText(result.get(position).getName());
   holder.file_path.setText(result.get(position).getPath());
}else{ 
   viewHolder = (ViewHolder) view.getTag(); 
}       
view.setTag(viewHolder);

ListView显示，但App在滚动和单击时崩溃

2 个答案: