4.0系统不允许主线程(UI线程)访问网络,因此导致了其异常
在4.0中,访问网络不能在主程序中进行,有两个方法可以解决,一个是在主程序中增加:
StrictMode is a developer tool which detects things you might be doing by accident and brings them to your attention so you can fix them.
// 详见StrictMode文档
StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
.detectDiskReads()
.detectDiskWrites()
.detectNetwork() // or .detectAll() for all detectable problems
.penaltyLog()
.build());
StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
.detectLeakedSqlLiteObjects()
.detectLeakedClosableObjects()
.penaltyLog()
.penaltyDeath()
.build());
另一种是启动线程执行下载任务:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new Thread(downloadRun).start();
}
/**
* 下载线程
*/
Runnable downloadRun = new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
updateListView();
}
};