[移动开发]Android Spinner 监听展开收起状态---亲测有效

在网上查了很多spinner，如何监听展开收起的状态，但是看了很多，只能看到展开，无法监听关闭，或者点击spinner外部区域关闭，也无法监听到。今天解决了，特此记录一下。

上图：

?上代码：

自定义Spinner，实现其中的方法：CustomSpinner：

public class CustomSpinner extends Spinner {


    private static final String TAG = "CustomSpinner";
    private OnSpinnerEventsListener mListener;
    private boolean mOpenInitiated = false;

    public CustomSpinner(Context context, AttributeSet attrs, int defStyleAttr, int mode) {
        super(context, attrs, defStyleAttr, mode);
    }

    public CustomSpinner(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

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

    public CustomSpinner(Context context, int mode) {
        super(context, mode);
    }

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

    public interface OnSpinnerEventsListener {

        void onSpinnerOpened();

        void onSpinnerClosed();

    }

    @Override
    public boolean performClick() {
        // register that the Spinner was opened so we have a status
        // indicator for the activity(which may lose focus for some other
        // reasons)
        mOpenInitiated = true;
        if (mListener != null) {
            mListener.onSpinnerOpened();
        }
        return super.performClick();
    }

    public void setSpinnerEventsListener(OnSpinnerEventsListener onSpinnerEventsListener) {
        mListener = onSpinnerEventsListener;
    }

    /**
     * Propagate the closed Spinner event to the listener from outside.
     */
    public void performClosedEvent() {
        mOpenInitiated = false;
        if (mListener != null) {
            mListener.onSpinnerClosed();
        }
    }

    /**
     * A boolean flag indicating that the Spinner triggered an open event.
     *
     * @return true for opened Spinner
     */
    public boolean hasBeenOpened() {
        return mOpenInitiated;
    }

    @Override
    public void onWindowFocusChanged(boolean hasWindowFocus) {
        android.util.Log.d(TAG, "onWindowFocusChanged");
        super.onWindowFocusChanged(hasWindowFocus);
        if (hasBeenOpened() && hasWindowFocus) {
            android.util.Log.i(TAG, "closing popup");
            performClosedEvent();
        }
    }

}

在布局文件中直接替换掉原生Spinner，class中不要忘记更改初始化对象

  /**
  * 监听展开收起
  */
  spinner.setSpinnerEventsListener(new CustomSpinner.OnSpinnerEventsListener() {
            @Override
            public void onSpinnerOpened() {
                HQLog.i(TAG,"open");
            }

            @Override
            public void onSpinnerClosed() {
                HQLog.i(TAG,"close");
            }
        });

?完毕。亲测有效！

只是一只老实的搬砖人..

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