Android-listview item 事件响 改变组件属性值问题（附图说明）

Question

问题：首先我在listView的item上放上了一些组件（例如button），然后我对item上组件进行设置监听事件，事件是在adapter里面设定的。代码如下：

    @Override
    public View getView(int position, View view, ViewGroup parent) {
        // TODO Auto-generated method stub
        //RecentViewHolder holder;
        if(view == null){
            holder = new RecentViewHolder();
            view = mInflater.inflate(R.layout.item_today_list, null);
            //findViewById
            holder.mXXxxx = (XXXXX) view.findViewById(R.id.XXXXXX);
            ....
            ....

            //设置响应(自定义函数)
            setItemOnClick(holder);
            //标记Tag
            view.setTag(holder);

        }else{

            holder = (RecentViewHolder) view.getTag();

        }
        

Answer 1

http://blog.csdn.net/aomandeshangxiao/article/details/7681380
看一下我写的这个博客吧，解决了这个问题。

Answer 2

参考@李鲁 的博文，做了下面的Demo，可以实现点击Button控制TextView的功能，原理就是在每次onClick事件后，执行notifyDataSetChanged()，然后再getView()方法中判断。

public class MainActivity extends ListActivity {

private MyListAdapter mAdapter;

private Context mContext=this;

private List<String> mList;

private List<Integer> mTextViewVisibility;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mList=getData();
mAdapter=new MyListAdapter();
this.setListAdapter(mAdapter);
}

private List<String> getData() {
mTextViewVisibility=new ArrayList<Integer>();
List<String> data=new ArrayList<String>();
for(int i=0; i < 20; i++) {
data.add("cstdr " + i);
mTextViewVisibility.add(1);
}
return data;
}

public final class ViewHolder {

public int id;

public RelativeLayout mRl;

public TextView mTv;

public Button mBtn;

}

public class MyListAdapter extends BaseAdapter {

private LayoutInflater inflater;

private ViewHolder holder;

MyListAdapter() {
inflater=LayoutInflater.from(mContext);
}

@Override
public int getCount() {
return mList.size();
}

@Override
public Object getItem(int position) {
return mList.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
if(convertView == null) {
holder=new ViewHolder();

convertView=inflater.inflate(R.layout.activity_main, null);

holder.id=position;
holder.mTv=(TextView)convertView.findViewById(R.id.text);
holder.mBtn=(Button)convertView.findViewById(R.id.btn);

convertView.setTag(holder);

} else {
holder=(ViewHolder)convertView.getTag();
}

holder.mTv.setText(mList.get(position));
if(mTextViewVisibility.get(position) == 1) {
holder.mTv.setVisibility(View.VISIBLE);
} else {
holder.mTv.setVisibility(View.GONE);
}

holder.mBtn.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
changeTextViewVisable(position);
notifyDataSetChanged();
}
});

return convertView;
}
}

public void changeTextViewVisable(int position) {
if(mTextViewVisibility.get(position) == 1) {
mTextViewVisibility.set(position, 0);
} else {
mTextViewVisibility.set(position, 1);
}
}

}

Answer 3

holder的使用是为了减少执行 findViewById()浪费的时间，所以首先需要明确地就是对控件设置或监听需要放在这些之外

 if (convertView == null) {
holder = new ViewHolder();
......
convertView.setTag(holder);

} else {
holder = (ViewHolder)convertView.getTag();
}
//以上之外

然后的工作就是对holder中的button调用 setTag(position); 记住位置并设置监听，在监听内获取组件的标签，代码如下

 holder.floorBtn.setTag(position);
holder.floorBtn.setOnClickListener(new OnClickListener(){

@Override
public void onClick(View v) {
int position = (Integer) v.getTag();
......
}

});

这样就应该可以获取正确的position了

Answer 4

由于listView 中item 里面的控件是复用的 所以每次执行到public View getView(int position, View view, ViewGroup parent) {

if(view==null
{
//这样是错误的当view不等于null 就不会从新设置响应，导致了你上面出现的问题
// setItemOnClick(holder);
}

//每次执行到这里都设置下响应
setItemOnClick(holder);

}函数是都要从新给某些元素绑定值