BaseAdapter导致notifyDataSetChanged()无效的三个原因及处理方法

原文  http://blog.csdn.net/dawanganban/article/details/21376979

前一段时间在做一个项目的时候遇到了一个关于BaseAdapter的notifyDataSetChanged()方法无效问题，当时在网上搜了一个解决方法，今天又遇到了一个类似的问题，我在这里做个记录，防止以后再次发生，或者其他朋友再次遇到。

一、ScrollView中嵌套ListView或GridView

原因：两个的滚动监听冲突

解决方法：重写ListView或GridView

package com.meritit.lottery.view;

import android.content.Context;
import android.util.AttributeSet;
import android.widget.ListView;

public class SerialListView extends ListView {

  public SerialListView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    // TODO Auto-generated constructor stub
  }

  public SerialListView(Context context, AttributeSet attrs) {
    super(context, attrs);
    // TODO Auto-generated constructor stub
  }

  public SerialListView(Context context) {
    super(context);
    // TODO Auto-generated constructor stub
  }

  /**
   * 为了取消滚动效果，可以放入滚动组建中重写了此方法
   */
  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,
        MeasureSpec.AT_MOST);
    super.onMeasure(widthMeasureSpec, expandSpec);
  }

}

二、ListView或GridView的外部容器重写onTouchEvent(MotionEvent event)方法

详细请看：http://blog.csdn.net/xxxzhi/article/details/12314775

这类问题解决方法很简单，只需要onTouchEvent返回false即可

例如：

@Override
  public boolean onTouchEvent(MotionEvent event) {
    // TODO Auto-generated method stub
          final int action = event.getAction();
          final float x = event.getX();
          final float y = event.getY();    

          switch (action) {
          case MotionEvent.ACTION_DOWN:
              System.out.println("父类点击onTouchEvent");
                Log.i("", "onTouchEvent  ACTION_DOWN");
              if (mVelocityTracker == null) {
                  mVelocityTracker = VelocityTracker.obtain();
                  mVelocityTracker.addMovement(event);
          }
              if (!mScroller.isFinished()){
                  mScroller.abortAnimation();
              }
              mLastMotionX = x;
              mLastMotionY = y;
              break;    

          case MotionEvent.ACTION_MOVE:
              System.out.println("父类滑动onTouchEvent");
               int deltaX = (int)(mLastMotionX - x);
                 if (IsCanMove(deltaX))
                 {
                   if (mVelocityTracker != null)
                     {
                            mVelocityTracker.addMovement(event);
                     }
                    mLastMotionX = x;
                    scrollBy(deltaX, 0);
                 }

             break;
          case MotionEvent.ACTION_UP:
              System.out.println("父类放开onTouchEvent");
              int velocityX = 0;
              if (mVelocityTracker != null)
              {
                  mVelocityTracker.addMovement(event);
                  mVelocityTracker.computeCurrentVelocity(1000);
                  velocityX = (int) mVelocityTracker.getXVelocity();
              }
              if (velocityX > SNAP_VELOCITY && mCurScreen > 0) {
                  // Fling enough to move left
                  Log.e(TAG, "snap left");
                  snapToScreen(mCurScreen - 1);
              } else if (velocityX < -SNAP_VELOCITY
                      && mCurScreen < getChildCount() - 1) {
                  // Fling enough to move right
                  Log.e(TAG, "snap right");
                  snapToScreen(mCurScreen + 1);
              } else {
                  snapToDestination();
              }      

              if (mVelocityTracker != null) {
                  mVelocityTracker.recycle();
                  mVelocityTracker = null;
              }
        //      mTouchState = TOUCH_STATE_REST;
              break;
          }
          return false;
  }

三、数据传值问题

注意改变Adapter内的数据，如下：list_contents和toparr是改变后的数据

mycqbaseAdapter.contents=list_contents;
    mycqtitleAdapter.toparr = toparr;
    mycqbaseAdapter.notifyDataSetChanged();
    mycqtitleAdapter.notifyDataSetChanged();

有一种错误的写法就是直接调用notifyData方法

mycqbaseAdapter.notifyDataSetChanged();
    mycqtitleAdapter.notifyDataSetChanged();