Spinner是没有点击事件接口的，如果你用setOnClickListener()，程序将会发生运行时异常。一般情况下，无需监控Spinner的点击事件，因为默认的处理方式是点击Spinner出现列表对话框，而某些时候，我们是需要处理点击事件的，比如：我们想在点击Spinner时更新它的列表项，更新完毕之后才显示新的列表框。那么这种情况下用Spinner显然行不通，针对这种情况，我做了一个继承自Spinner含点击事件监控接口的子控件。
代码如下：
import android.content.Context;
import android.graphics.Point;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.Spinner;
/**
* 继承自Spinner的自定义下拉列表框。该下拉列表有如下特点：
* <ol>
* <li>使用{@link #setOnClickMyListener(OnClickMyListener)}可监控点击事件，并可自行实现点击后的响应动作（原来Spinner的响应动作是打开列表选择框）。</li>
* <li>点击事件发生后，默认不再打开列表选择框，如需打开，请调用{@link #performClick()}</li>
* </ol>
* 该控件的目地在于弥补Spinner对于点击事件不能自定义响应的不足，Spinner对应点击的响应有自己的内在方案，
* 对外屏蔽了{@link #setOnClickListener(OnClickListener)}接口，
* 如果我们需要在点击控件后列表选择框出现前做某些事情（如：更新列表），
* 那么我们发现用Spinner根本无从下手，此控件弥补了这些不足。在监控到点击事件后，我们可执行一些动作，
* 动作执行完毕，只需要手动使用{@link #performClick()}显示列表选择框即可。
* <p />
*
* The class inherited from Spinner. The drop-down list has the following characteristics:
* <ol>
* <li> Use {@link #setOnClickMyListener(OnClickMyListener)} to listen the click event and can implement self-fulfilling click response action (Spinner's default response action is to open the list selection box). </ li>
* <li> Click event occurs, the default response is no longer open the list selection box, please call {@link #performClick()} instead. </ li>
* </ol>
* The purpose of the control is to compensate for that Spinner click event can not be caught, the Spinner has its own solution with the click event response,
* and {@link #setOnClickListener(OnClickListener)} interface is shielded,
* if we need to do something (such as update list) after click event happened and before the list selection box appears,
* we'll find no way, but ClickControlledSpinner did, it listens the click event, can let us perform some actions after this,
* after actions finished, we must revoke {@link #performClick()} to display the list selection box.
*
* @date 2012/08/24
* @author Wison Xu
*/
public class ClickControlledSpinner extends Spinner {
public ClickControlledSpinner(Context context) {
super(context);
}
public ClickControlledSpinner(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public ClickControlledSpinner(Context context, AttributeSet attrs) {
super(context, attrs);
}
private boolean isMoved = false;
private Point touchedPoint = new Point();
@Override
public boolean onTouchEvent(MotionEvent event) {
int x = (int) event.getRawX();
int y = (int) event.getRawY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touchedPoint.x = x;
touchedPoint.y = y;
break;
case MotionEvent.ACTION_MOVE:
isMoved = true;
break;
case MotionEvent.ACTION_UP:
if (isMoved) {
// 从上向下滑动
if (y - touchedPoint.y > 20) {
}
// 从下向上滑动
else if (touchedPoint.y - y > 20) {
}
// 滑动幅度小时，当作点击事件
else {
onClick();
}
isMoved = false;
} else {
onClick();
}
break;
default:
break;
}
return true;
}
private void onClick() {
if (onClickMyListener != null && isEnabled()) {
// use a thread to do something which maybe spend many times.
new Thread() {
public void run() {
onClickMyListener.onClick();
}
}.start();
}
}
private OnClickMyListener onClickMyListener;
/**
* 注册自定义的点击事件监听
* Register the click event self-fulfilling listener.
* @param onClickMyListener
*/
public void setOnClickMyListener(OnClickMyListener onClickMyListener) {
this.onClickMyListener = onClickMyListener;
}
/**
* 自定义点击事件监听.
* Click event self-fulfilling listener.
* @author Wison Xu
*/
public interface OnClickMyListener {
/**
* 点击时触发
* 警告：该方法在非UI线程中执行
*
* Triggers when click event occurs.
* Warning: this method does not run in UI thread.
*/
public void onClick() ;
}
}