轉(zhuǎn)自:http://blog.csdn.net/u011889786/article/details/52143268
一涵紊、ListView
原因
ListView的高度不確定技扼,一般用的是wrap_content,導(dǎo)致系統(tǒng)需要不斷測量,也就多次調(diào)用onMeasure()方法,所以就多次調(diào)用getView()方法锦庸。
解決方法
把寬高寫死(給個精確數(shù)字,或者match_parent)
二、GridView
原因
貌似不管長寬寫不寫死都是會多次調(diào)用getView绳慎。。漠烧。原因待補充
解決方法
onMeasure()調(diào)用getView的時候不要去對convertView做任何賦值的操作偷线,只有當(dāng)onLayout的時候我們再對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調(diào)用的就立即返回
return convertView;
}
System.out.println("xcqw getView 2***position"+position);
//如果不是onMeasure調(diào)用的就可以正常賦值操作
String content = contentList.get(position);
holder.tvContent.setText(content);
return convertView;
}