Question

我有一个列表，显示每行多个项目。两个按钮和四个textview。

我正在使用ArrayAdapter来修改我的自定义布局并填写每行中的数据。

显示所有想要的信息，我可以与按钮进行交互。（每个按钮更改其行的文本视图。）

一切正常，直到我再次向下滚动。比什么都没有了。所有项目仍然存在，但通过单击按钮，文本不再更改。

（我将所有创建的TextView保存在Vector中，因为使用getView方法的position属性，我得到了我在列表中单击的项目的位置，因此我可以从向量中选择一个特定的一个。它可以很好地工作，直到as我写道，我滚动列表）

这是我的ArrayAdapter的代码

public class LocationlistAdapter extends ArrayAdapter<Location> {

// GUI elements
private Button btnCheckin;
private Button btnExit;
private Vector<TextView> locationList = new Vector<TextView>();
private Vector<TextView> checkInList = new Vector<TextView>();
private Vector<TextView> checkOutList = new Vector<TextView>();
private Vector<TextView> lastVisitList = new Vector<TextView>();

private boolean checkedIn = false;
private int activeListPosition = -1; // selected ListView item

private static LocationTrackingDB mDBHandler;

public LocationlistAdapter(Context context, List<Location> locations) {
    super(context, R.layout.locationlistrow, locations);

    mDBHandler = LocationTrackingDB.getInstance(getContext());
}

@Override
public View getView(final int position, View view, ViewGroup parent) {
    LayoutInflater inflater = (LayoutInflater) parent.getContext()
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View v = inflater.inflate(R.layout.locationlistrow, null);

    if (position % 2 == 0) {
        RelativeLayout layout = (RelativeLayout) v
                .findViewById(R.id.rowLayout);
        layout.setBackgroundColor(Color.DKGRAY);
    } else {
        RelativeLayout layout = (RelativeLayout) v
                .findViewById(R.id.rowLayout);
        layout.setBackgroundColor(Color.BLACK);
    }

    TextView txtLocationName = (TextView) v
            .findViewById(R.id.txtLocationName);
    TextView txtStartTime = (TextView) v.findViewById(R.id.txtStartTime);
    TextView txtEndTime = (TextView) v.findViewById(R.id.txtEndTime);
    TextView txtLastDate = (TextView) v.findViewById(R.id.txtLastDate);

    if (locationList.size() < mDBHandler.getAllLocations().size()) {
        locationList.add(txtLocationName);
        checkInList.add(txtStartTime);
        checkOutList.add(txtEndTime);
        lastVisitList.add(txtLastDate);
    }

    txtLocationName.setText(mDBHandler.getLocation(position + 1).getName());
    txtStartTime.setText(mDBHandler.getLocation(position + 1)
            .getStartTime());
    txtEndTime.setText(mDBHandler.getLocation(position + 1).getEndTime());
    txtLastDate
            .setText(mDBHandler.getLocation(position + 1).getLastVisit());

    btnCheckin = (Button) v.findViewById(R.id.btnCheckIn);
    btnExit = (Button) v.findViewById(R.id.btnExit);

    btnCheckin.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            if (!checkedIn && activeListPosition == -1) {
                checkedIn = true;
                activeListPosition = position;

                Location tmpLocation = mDBHandler.getLocation(position + 1);

                SimpleDateFormat time = new SimpleDateFormat("HH:mm:ss");
                SimpleDateFormat date = new SimpleDateFormat("dd/MM/yyyy");
                Date currentTime = new Date();
                checkInList.elementAt(position).setText(
                        time.format(currentTime));
                lastVisitList.elementAt(position).setText(
                        date.format(currentTime));
                checkOutList.elementAt(position).setText("waiting ...");

                tmpLocation.setStartTime(time.format(currentTime));
                tmpLocation.setLastVisit(date.format(currentTime));

                mDBHandler.updateLocation(tmpLocation);
            }
        }
    });

    btnExit.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            if (checkedIn && activeListPosition == position) {
                Location tmpLocation = mDBHandler.getLocation(position + 1);

                checkedIn = false;
                activeListPosition = -1;

                SimpleDateFormat time = new SimpleDateFormat("HH:mm:ss");
                SimpleDateFormat date = new SimpleDateFormat("dd/MM/yyyy");
                Date currentTime = new Date();
                checkOutList.elementAt(position).setText(
                        time.format(currentTime));

                tmpLocation.setEndTime(time.format(currentTime));
                tmpLocation.setLastVisit(date.format(currentTime));

                mDBHandler.updateLocation(tmpLocation);
            }
        }
    });
    return v;
    }
}

有没有人知道为什么会这样？或者我如何才能做到更好的方式呢？

Answer 1

尝试使用getView函数参数中的convertView（在您的情况下为视图），如：

@Override
public View getView(final int position, View view, ViewGroup parent) {
View v=view;
if(v==null){
    LayoutInflater inflater = (LayoutInflater) parent.getContext()
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
     v = inflater.inflate(R.layout.locationlistrow, null);
}

...
...
}

还尝试使用此适配器代码：

public class LocationlistAdapter extends ArrayAdapter<Location> {

    // GUI elements
    private Button btnCheckin;
    private Button btnExit;

    private boolean checkedIn = false;
    private int activeListPosition = -1; // selected ListView item

    private static LocationTrackingDB mDBHandler;

    public LocationlistAdapter(Context context, List<Location> locations) {
        super(context, R.layout.locationlistrow, locations);

        mDBHandler = LocationTrackingDB.getInstance(getContext());
    }

    @Override
    public View getView(final int position, View view, ViewGroup parent) {
        View v = view;
        if (v == null) {
            LayoutInflater inflater = (LayoutInflater) parent.getContext()
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            v = inflater.inflate(R.layout.locationlistrow, null);
        }
        if (position % 2 == 0) {
            RelativeLayout layout = (RelativeLayout) v
                    .findViewById(R.id.rowLayout);
            layout.setBackgroundColor(Color.DKGRAY);
        } else {
            RelativeLayout layout = (RelativeLayout) v
                    .findViewById(R.id.rowLayout);
            layout.setBackgroundColor(Color.BLACK);
        }

        final TextView txtLocationName = (TextView) v
                .findViewById(R.id.txtLocationName);
        final TextView txtStartTime = (TextView) v
                .findViewById(R.id.txtStartTime);
        final TextView txtEndTime = (TextView) v.findViewById(R.id.txtEndTime);
        final TextView txtLastDate = (TextView) v
                .findViewById(R.id.txtLastDate);

        txtLocationName.setText(mDBHandler.getLocation(position + 1).getName());
        txtStartTime.setText(mDBHandler.getLocation(position + 1)
                .getStartTime());
        txtEndTime.setText(mDBHandler.getLocation(position + 1).getEndTime());
        txtLastDate
                .setText(mDBHandler.getLocation(position + 1).getLastVisit());

        btnCheckin = (Button) v.findViewById(R.id.btnCheckIn);
        btnExit = (Button) v.findViewById(R.id.btnExit);

        btnCheckin.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                if (!checkedIn && activeListPosition == -1) {
                    checkedIn = true;
                    activeListPosition = position;

                    Location tmpLocation = mDBHandler.getLocation(position + 1);

                    SimpleDateFormat time = new SimpleDateFormat("HH:mm:ss");
                    SimpleDateFormat date = new SimpleDateFormat("dd/MM/yyyy");
                    Date currentTime = new Date();
                    txtLocationName.setText(time.format(currentTime));
                    txtLastDate.setText(date.format(currentTime));
                    txtEndTime.setText("waiting ...");

                    tmpLocation.setStartTime(time.format(currentTime));
                    tmpLocation.setLastVisit(date.format(currentTime));

                    mDBHandler.updateLocation(tmpLocation);
                }
            }
        });

        btnExit.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                if (checkedIn && activeListPosition == position) {
                    Location tmpLocation = mDBHandler.getLocation(position + 1);

                    checkedIn = false;
                    activeListPosition = -1;

                    SimpleDateFormat time = new SimpleDateFormat("HH:mm:ss");
                    SimpleDateFormat date = new SimpleDateFormat("dd/MM/yyyy");
                    Date currentTime = new Date();
                    txtEndTime.setText(time.format(currentTime));

                    tmpLocation.setEndTime(time.format(currentTime));
                    tmpLocation.setLastVisit(date.format(currentTime));

                    mDBHandler.updateLocation(tmpLocation);
                }
            }
        });
        return v;
    }
}

滚动后无法与自定义列表视图布局上的按钮正确交互

1 个答案: