BaseAdapter导致notifyDataSetChanged()无效的四个原因及处理方法

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();

四、ViewGroup中notifyDataSetChanged()无效

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
// if (changed) {
menu_view = getChildAt(0);
content_view = getChildAt(1);

content_view.measure(0, 0);
content_view.layout(0, 0, getWidth(), getHeight());
// }
}

注释掉onLayout中的if(changed)即可。