哪个activity调用了适配器

Question

我正在使用适配器来填充列表视图，我在 2 个活动中使用相同的适配器，但我需要在一种情况下而不是在另一种情况下隐藏布局的元素。那么有没有办法找出哪个 activity 调用了适配器（在适配器 class 中）？

public class Db_adapter extends BaseAdapter {

private Context mContext;
private List<db_list> mDataList;
private LayoutInflater mLayoutInflater;
private String TAG = this.getClass().getSimpleName();

public Db_adapter(Context mContext, List<db_list> mDataList) {
    this.mContext = mContext;
    this.mDataList = mDataList;
    this.mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public void notifyDataSetChanged() {
    super.notifyDataSetChanged();
}

@Override
public int getViewTypeCount() {
    return super.getViewTypeCount();
}

@Override
public int getCount() {
    return mDataList.size();
}

@Override
public Object getItem(int position  ) {
    return mDataList.get(position);
}

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

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    ViewHolder viewHolder = null;
    if (convertView == null) {
        viewHolder = new ViewHolder();
        convertView = mLayoutInflater.inflate(R.layout.dblayout,parent,false);
        viewHolder.tv_db_name= (TextView) convertView.findViewById(R.id.tv_db_name);
        viewHolder.tv_db_number = (TextView) convertView.findViewById(R.id.tv_db_number);
        viewHolder.iv_delete = (ImageView)convertView.findViewById(R.id.iv_delete);
        convertView.setTag(viewHolder);
    }
    else{
        viewHolder = (ViewHolder) convertView.getTag();
    }



    db_list rowData = mDataList.get(position);
    viewHolder.tv_db_name.setText(rowData.getDb_name());
    viewHolder.tv_db_number.setText(rowData.getDn_number());
    viewHolder.iv_delete.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            new DeleteDb_async().execute(Add_deliveryBoy.db_id_list.get(position), String.valueOf(position));

        }
    });

    return convertView;
}

public void onDataSetChanged(List<db_list> mDataList) {
    this.mDataList = mDataList;
    notifyDataSetChanged();
}

private class ViewHolder{
    private TextView tv_db_name,tv_db_number;
    private ImageView iv_delete;
}

Answer 1

So is there a way to figure out which activity called the adapter (in the adapter class )

当然可以。简单的事情是从 Adapter 构造函数发送一个附加参数并找出哪个 class 调用它。创建一个字符串字段。

String className;

在构造函数中：

    public Db_adapter(Context mContext, List<db_list> mDataList, String className) {
    //make a field and assign it with className
this.className = className
    }

并且在显示或隐藏时，

if(className.equals("ClassA")){
//hide something
yourTextView.setVisibility(View.GONE);
}else if(className.equals("ClassB")){
//show something
yourTextView.setVisibility(View.VISIBLE);
}

Answer 2

您可以使用mContext。 Adapter 被实例化的时间是有价值的。是 Activity 创建了它。因此，您可以使用任何您喜欢的方法，让 Activity 对象触手可及。

Answer 3

您可以创建另一个构造函数，再添加一个 boolean 值并将其存储在适配器中的变量中，如下所示：

boolean flag;    

public Db_adapter(Context mContext, List<db_list> mDataList,boolean anotherAcivityFlag) {
    this.mContext = mContext;
    this.mDataList = mDataList;
    flag = anotherAcivityFlag;
    this.mLayoutInflater = (LayoutInflater)     mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

public Db_adapter(Context mContext, List<db_list> mDataList) {
    this.mContext = mContext;
    this.mDataList = mDataList;
    flag = false;
    this.mLayoutInflater = (LayoutInflater)     mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

在 getView() 中添加一个 if 语句来检测您要加载的视图。

现在用构造函数初始化适配器以区分 bw 活动。

Answer 4

正如您所说，让我们假设我有两个活动 ActivityOne 和 ActivityTwo

Context context;
List<db_list> mDataList;

public Db_adapter(Context context, List<db_list> mDataList) {
    this.context = context;
    this.mDataList = mDataList;
}

在你的方法中你可以这样做

if(context instanceof ActivityOne) {
    // setVisibility
} else if(context instanceof ActivityTwo) {
    // setVisibility
}

哪个activity调用了适配器

Which activity called the adapter

android

adapter

baseadapter