android空指针问题

[qq_29754803]

public class FiveActivity extends Activity {
private TextView textView;

private Handler handler = new Handler(){
public void handleMessage(android.os.Message msg) {

};
};

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.five);
textView = (TextView) findViewById(R.id.textview);
new Thread(){
public void run() {
try {
Thread.sleep(2000);

handler.post(new Runnable() {

@Override
public void run() {
// TODO Auto-generated method stub
textView.setText("ok");
}
});
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}.start();
}
}

报错是textView.setText("ok");空指针

[JPF1024]

嗯写代码多注意下就可以了

[聂建jian]

public class FiveActivity extends Activity { private TextView textView; private Handler handler = new Handler() { public void handleMessage(android.os.Message msg) { switch (msg.what) { case 0: break; default: break; } }; }; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.five); textView = (TextView) findViewById(R.id.textview); handler.sendMessageDelayed(0, 2000); } } 这样写就清晰多了，同样的效果，两秒之后发送

[聂建jian]

上面发错了

[聂建jian]

你在handler中更新ui就挺好的，不会阻塞，也不会崩掉

[Hare_]

确认layout文件中有有TextView

[Sero_T]

异步不能直接更新UI吧！

[qq_29754803]

晕死，这个项目建了太多类，textView = (TextView) findViewById(R.id.textview);调用了另外一个xml的textview

[逆转星河]

你最后那个报错的问题：rebuild或者clean一下工程试试