转自:http://blog.csdn.net/u011889786/article/details/52143268
一、ListView
原因
ListView的高度不确定,一般用的是wrap_content,导致系统需要不断测量,也就多次调用onMeasure()方法,所以就多次调用getView()方法。
解决方法
把宽高写死(给个精确数字,或者match_parent)
二、GridView
原因
貌似不管长宽写不写死都是会多次调用getView。。。原因待补充
解决方法
onMeasure()调用getView的时候不要去对convertView做任何赋值的操作,只有当onLayout的时候我们再对ConvertView操作
public class MyGridView extends GridView {
public boolean isOnMeasure;
public MyGridView(Context context) {
super(context);
}
public MyGridView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MyGridView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
isOnMeasure = true;
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
isOnMeasure = false;
super.onLayout(changed, l, t, r, b);
}
}
adapter getView();
public View getView(int position, View convertView, ViewGroup parent) {
System.out.println("xcqw getView 1***position"+position);
ViewHolder holder = null;
if (convertView == null) {
convertView = inflater.inflate(R.layout.item,
parent, false);
holder = new ViewHolder();
holder.tvContent = (TextView) convertView.findViewById(R.id.tv_content);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
if(((MyGridView) parent).isOnMeasure){
//如果是onMeasure调用的就立即返回
return convertView;
}
System.out.println("xcqw getView 2***position"+position);
//如果不是onMeasure调用的就可以正常赋值操作
String content = contentList.get(position);
holder.tvContent.setText(content);
return convertView;
}