如何对相同的微调器值选择调用操作答案

【问题标题】：How can I invoke an action on the same selection of spinner value如何对相同的微调器值选择调用操作
【发布时间】：2013-10-07 19:23:50
【问题描述】：

我从微调器中选择值，当我再次选择相同的值时，点击不会执行任何操作。

【问题讨论】：

跟踪先前选择的值...并检查当前选择的值是否是前一个
检查当前选择值和前一个是否相同。

标签： android android-spinner

【解决方案1】：

使用这个自定义 Spinner 类...

/** Spinner extension that calls onItemSelected even when the selection is the same as its previous value */
public class NDSpinner extends Spinner {

  public NDSpinner(Context context)
  { super(context); }

  public NDSpinner(Context context, AttributeSet attrs)
  { super(context, attrs); }

  public NDSpinner(Context context, AttributeSet attrs, int defStyle)
  { super(context, attrs, defStyle); }

  @Override public void
  setSelection(int position, boolean animate)
  {
    boolean sameSelected = position == getSelectedItemPosition();
    super.setSelection(position, animate);
    if (sameSelected) {
      // Spinner does not call the OnItemSelectedListener if the same item is selected, so do it manually now
      getOnItemSelectedListener().onItemSelected(this, getSelectedView(), position, getSelectedItemId());
    }
  }

  @Override public void
  setSelection(int position)
  {
    boolean sameSelected = position == getSelectedItemPosition();
    super.setSelection(position);
    if (sameSelected) {
      // Spinner does not call the OnItemSelectedListener if the same item is selected, so do it manually now
      getOnItemSelectedListener().onItemSelected(this, getSelectedView(), position, getSelectedItemId());
    }
  }
}

【讨论】：