Android GridView中改变了某一个View的内容，如何立即让其刷新？
0
悬赏园豆：10
[已解决问题]
解决于 2014-04-22 21:41
大家好：
写了一个GridView，自定义的一个Adapter，设置了OnItemClickListner改变了GridView的Adapter的数据，并调用了GridView的postInvalidate()。这样，再滚动GridView的时候才能将变化显现出来——具体变化是：点击了那个item，那个item的背景会变成黑色（见图）。
现在的疑问是：用什么方法，在点击了之后，立马就将变化体现出来？
package com.example.regreshgridvdemo; import android.app.Activity; import android.content.Context; import android.graphics.Color; import android.os.Bundle; import android.util.Log; import android.view.Menu; import android.view.View; import android.view.ViewGroup; import android.widget.Adapter; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.BaseAdapter; import android.widget.GridView; import android.widget.TextView; public class MainActivity extends Activity { GridView gridV; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); //setContentView(R.layout.activity_main); gridV = new GridView(this); gridV.setAdapter(new cAdapter(this)); gridV.setOnItemClickListener(l); gridV.setVerticalSpacing(10); gridV.setHorizontalSpacing(10); gridV.setNumColumns(4); setContentView(gridV); } OnItemClickListener l = new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Adapter adapter = parent.getAdapter(); if(adapter != null && adapter instanceof cAdapter){ ((cAdapter)adapter).setCrtId(position); parent.postInvalidate(); Log.i("xxx", "position=" + position + " id=" + id); } } }; @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.activity_main, menu); return true; } } class cAdapter extends BaseAdapter{ final int CNT = 100; int crt = 0; Context mCtx; public cAdapter(Context ctx) { mCtx = ctx; } public void setCrtId(int i){ crt = i; } @Override public int getCount() { return CNT; } @Override public Object getItem(int position) { return new Integer(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { TextView txt = null; if(convertView == null) txt = new TextView(mCtx); else if(convertView instanceof TextView) txt = (TextView) convertView; txt.setTextSize(30); txt.setText("ID=" + position); txt.setTextColor(Color.RED); txt.setBackgroundColor(position == crt ? Color.BLACK : Color.YELLOW); return txt; } }
最佳答案
0
解决的办法是：
在OnItemClickListener里调用adapter的notifyDataSetChanged()方法——注意，Adapter必须继承BaseAdapter才行，因为notifyDataSetChanged()方法是BaseAdapter中的方法。
OnItemClickListener l = new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Adapter adapter = parent.getAdapter(); if(adapter != null && adapter instanceof cAdapter){ MainActivity.this.adapter.setCrtId(position); MainActivity.this.adapter.notifyDataSetChanged(); Log.i("xxx", "in listener position=" + position + " id=" + id); } } };
