Android进度对话框或定位更改

您好，我有这样的问题，我有一个asynctask和progress对话框，当我旋转手机时，它失败了，我知道该活动已取消，我们需要创建新的。所以代码

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而且它在失败的时候失败了。如何修复？谢谢。

为什么进度对话框是静态的？@blackbelt i删除静态-相同

public class GetWeather extends AsyncTask<String, Void, WeatherInfo> {
    FragmentActivity activity;
    public GetWeather(FragmentActivity a){
        activity = a;
    }
    static ProgressDialog progressDialog;
    public void showDialog() {
        progressDialog = new ProgressDialog(activity);
        /*Some stuff for dialog*/
        progressDialog.show();
    }
    @Override
    protected void onPreExecute() {
        showDialog();
    }
 protected void onPostExecute(WeatherInfo result){
        progressDialog.dismiss();
}
}

public class MyActivity extends FragmentActivity implements CityList.OnItemSelectedListener {
    GetWeather weather = null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        weather = (GetWeather) getLastCustomNonConfigurationInstance();
        if (weather != null){
            weather.activity = this;
            weather.showDialog();
        }