Question

我必须遗漏一些明显但无法找到它的东西。

在下面的函数中，如果我尝试加载我的Drawable数组，我得到一个空指针异常，说getResource是在空指针处调用的，而如果我直接传递drawable并在上下文的帮助下膨胀它，它工作正常。

我在这里做错了什么？请帮忙。

class MyDrawerAdapter extends BaseAdapter {
private Context context;
String[] drawerList;


public MyDrawerAdapter(Context context) {
    drawerList = context.getResources().getStringArray(R.array.Cat_array);
    this.context = context;

}
/*
Drawable[] drawableArr ={MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home),
        MrVector.inflate(context.getResources(),R.drawable.home)};
*/
@Override
public int getCount() {
    return drawerList.length;
}

@Override
public Object getItem(int position) {
    return null;
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public int getViewTypeCount() {
    return 3;
}

@Override
public int getItemViewType(int position) {
    if (position == 3 || position == 11) {
        return 1;
    }
    if (position == 4) {
        return 2;
    }
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row = null;
    LayoutInflater inflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
    if (getItemViewType(position) == 1) {
        if (convertView == null) {
            row = inflater.inflate(R.layout.divider, parent, false);
        } else {
            row = convertView;
        }
        row.setEnabled(false);
        row.setOnClickListener(null);
    }
    if (getItemViewType(position) == 0) {
        if (convertView == null) {
            row = inflater.inflate(R.layout.drawer_list_item, parent, false);
        } else {
            row = convertView;
        }
        TextView titletext = (TextView) row.findViewById(R.id.drawer_text);
        ImageView titleImage = (ImageView) row.findViewById(R.id.drawer_image);
        titletext.setText(drawerList[position]);
        //titleImage.setImageDrawable(drawableArr[position]);
        titleImage.setImageDrawable(MrVector.inflate(context.getResources(),R.drawable.home));
    }
    if (getItemViewType(position) == 2) {
        if (convertView == null) {
            row = inflater.inflate(R.layout.header_listview_menu, parent, false);
        } else {
            row = convertView;
        }
        row.setEnabled(false);
        row.setOnClickListener(null);
    }
    return row;
}

}

Answer 1

这是我已经实施的解决方法，但如果有人可以提供帮助，我们仍然希望得到答案。

class MyDrawerAdapter extends BaseAdapter {
private Context context;
String[] drawerList;    

public MyDrawerAdapter(Context context) {
    drawerList = context.getResources().getStringArray(R.array.Cat_array);
    this.context = context;

}

@Override
public int getCount() {
    return drawerList.length;
}

@Override
public Object getItem(int position) {
    return null;
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public int getViewTypeCount() {
    return 3;
}

@Override
public int getItemViewType(int position) {
    if (position == 3 || position == 11) {
        return 1;
    }
    if (position == 4) {
        return 2;
    }
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row = null;
    int layoutID = context.getResources().getIdentifier("icon_" + position, "drawable", context.getApplicationInfo().packageName);
    LayoutInflater inflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
    if (getItemViewType(position) == 1) {
        if (convertView == null) {
            row = inflater.inflate(R.layout.divider, parent, false);
        } else {
            row = convertView;
        }
        row.setEnabled(false);
        row.setOnClickListener(null);
    }
    if (getItemViewType(position) == 0) {
        if (convertView == null) {
            row = inflater.inflate(R.layout.drawer_list_item, parent, false);
        } else {
            row = convertView;
        }
        TextView titletext = (TextView) row.findViewById(R.id.drawer_text);
        ImageView titleImage = (ImageView) row.findViewById(R.id.drawer_image);
        titletext.setText(drawerList[position]);

        titleImage.setImageDrawable(MrVector.inflate(context.getResources(),layoutID));
    }
    if (getItemViewType(position) == 2) {
        if (convertView == null) {
            row = inflater.inflate(R.layout.header_listview_menu, parent, false);
        } else {
            row = convertView;
        }
        row.setEnabled(false);
        row.setOnClickListener(null);
    }
    return row;
}

}

BaseAdapter上下文检索奇怪的行为

1 个答案: