Question

我只在屏幕上显示的列表视图的第一项上有奇怪的行为;它坚持第二个。它是一个动态列表视图，用户可以在其中写入文本并添加/删除新行。请参阅以下代码：

添加新行的按钮代码：

add_task.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            job_task_array.add(new JobTask_Model("", 50));
            job_task_update(rootView, item_job_task_height);
            for (int i = 0; i < job_task_array.size(); i++)
                Log.e("job_task", job_task_array.get(i).getJob_task_name());
        }
    });

单击上面的按钮后，此部分会对其进行动画处理：

    // This is called whenever we click 'add task' or 'delete task', does the whole animation cycle
public void job_task_update(final View view, final int job_task_heightmove) {
    add_task.setEnabled(false);
    Animation animation = new Animation() {
        @Override
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            job_task_listView.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, (int) (job_task_height + (job_task_heightmove * interpolatedTime))));
        }
    };
    animation.setDuration(CreatePostingActivity.animationTime);
    view.startAnimation(animation); // Update job_task_height's value AFTER the shit animates because apparently it takes the current job_task_height
    view.postOnAnimationDelayed(new Runnable() {
        @Override
        public void run() {
            job_task_height += job_task_heightmove;
            add_task.setEnabled(true);
        }
    }, CreatePostingActivity.animationTime * 2);
}

自定义适配器：

    // Object model for the posting_2 job_task_listView
public class JobTask_Model {
    private int job_task_seekbar_value;
    private String job_task_name;

    public JobTask_Model(String job_task_name, int job_task_seekbar_value) {
        this.job_task_seekbar_value = job_task_seekbar_value;
        this.job_task_name = job_task_name;
    }

    public String getJob_task_name() {
        return job_task_name;
    }

    public int getJob_task_seekbar_value() {
        return job_task_seekbar_value;
    }
}

/**
 * This class is the adapter for the tasks
 **/
public class JobTasks_Adapter extends ArrayAdapter {
    private final ArrayList<JobTask_Model> job_task_array;
    private Context context;

    public JobTasks_Adapter(Context context, ArrayList arrayList) {
        super(context, R.layout.item_job_task, arrayList);
        this.context = context;
        job_task_array = arrayList;
    }

    // Create static class for our special viewholder model, references item_job_task layout
    class JobTask_ViewHolder {
        EditText job_task_name;
        SeekBar job_task_seekbar;
        Button job_task_delete;
    }

    // This gets the view
    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        View view = convertView;
        if (view == null) {
            LayoutInflater layoutInflater = ((Activity) context).getLayoutInflater();
            view = layoutInflater.inflate(R.layout.item_job_task, parent, false);
            // configure view holder
            JobTask_ViewHolder viewHolder = new JobTask_ViewHolder();
            viewHolder.job_task_name = (EditText) view.findViewById(R.id.job_task_name);
            viewHolder.job_task_seekbar = (SeekBar) view.findViewById(R.id.job_task_seekbar);
            viewHolder.job_task_delete = (Button) view.findViewById(R.id.job_task_delete);
            view.setTag(viewHolder);
        }
        JobTask_ViewHolder viewHolder = (JobTask_ViewHolder) view.getTag();

        // Set the bar value so it doesn't reset when we add another one in
        viewHolder.job_task_seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
            }

            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                job_task_array.get(position).job_task_seekbar_value = progress;
            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
            }
        });

        viewHolder.job_task_name.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                job_task_array.get(position).job_task_name = s.toString();
            }

            @Override
            public void afterTextChanged(Editable s) {
            }
        });

        // Button to delete each task
        viewHolder.job_task_delete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                job_task_array.remove(position);
                job_task_update(rootView, -item_job_task_height);
            }
        });

        viewHolder.job_task_seekbar.setProgress(job_task_array.get(position).getJob_task_seekbar_value());
        viewHolder.job_task_name.setText(job_task_array.get(position).getJob_task_name());

        return view;
    }
}

Answer 1

在此方法中添加一些logcat语句，

这可以帮助您查看＆＃39;标记＆＃39;正确关联（创建/读取），因为相同的2个视图应该具有不同的标记＆＃39;对象。

{{1}}

Answer 2

When position == 0, view == null.

 @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
            View view = convertView;
             JobTask_ViewHolder viewHolder 
            if (view == null) {
                LayoutInflater layoutInflater = ((Activity) context).getLayoutInflater();
                view = layoutInflater.inflate(R.layout.item_job_task, parent, false);
                // configure view holder
                viewHolder = new JobTask_ViewHolder();
                viewHolder.job_task_name = (EditText) view.findViewById(R.id.job_task_name);
                viewHolder.job_task_seekbar = (SeekBar) view.findViewById(R.id.job_task_seekbar);
                viewHolder.job_task_delete = (Button) view.findViewById(R.id.job_task_delete);
                view.setTag(viewHolder);
            }else{
              viewHolder = (JobTask_ViewHolder) view.getTag();
            }
    ...
    }

Answer 3

您的static不是静态

制作此：

// Create static class for our special viewholder model, references item_job_task layout
class JobTask_ViewHolder {
    EditText job_task_name;
    SeekBar job_task_seekbar;
    Button job_task_delete;
}

INTO THIS：

// Create static class for our special viewholder model, references item_job_task layout
static class JobTask_ViewHolder {
    EditText job_task_name;
    SeekBar job_task_seekbar;
    Button job_task_delete;
}

How can I make my ArrayAdapter follow the ViewHolder pattern?作为示例

Android自定义arrayadapter＆amp; listview奇怪的行为

3 个答案: