下面是我的代码。我在这里运行一个带有标题的 ProgressBar 线程。
在线程的 run() 中，如果我的互联网连接正常，则 ELSE 部分将执行并关闭该 ProgressBar。但是，如果我的互联网连接不工作，那么如果 pat 被执行，当我尝试关闭 ProgressBar 时，我得到空异常。我还添加了 null 检查if(m_ProgressDialog == null)，并在 NULL 中打印 DialobBox ..
我的代码怎么了？ProgressBar 在 ELSE 部分中解散，但在 IF 中抛出 NULL 异常...
public void onCreate(Bundle savedInstanceState) {
.....................
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//some CODE //
.....................
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viewOrders = new Runnable(){
@Override
public void run() {
try {
if(!utilityFunctions.HaveNetworkConnection(SplashScreenActivity.this)) //checking internet connection
{
Log.i(UtilityFunctions.APP_TAG, "NO Connecttion");
//updateUI(0);
if(m_ProgressDialog == null)
Log.i(UtilityFunctions.APP_TAG, "DialogBox is NULL");
else
m_ProgressDialog.dismiss();
Log.i(UtilityFunctions.APP_TAG, "Dismissed");
handler.sendEmptyMessage(0);
}
else
{
try {
m_ProgressDialog.dismiss();
}
} catch (Exception e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Intent mainIntent = new Intent().setClass(SplashScreenActivity.this, MainActivity.class);
Log.i(UtilityFunctions.APP_TAG, "Starting Program");
startActivity(mainIntent);
finish();
}
}
catch(Exception e) {
e.printStackTrace();
}
}
private Handler handler = new Handler()
{
@Override
public void handleMessage(Message msg) {
//super.dispatchMessage(msg);
super.handleMessage(msg);
updateUI(msg.what);
}
};
};
Thread thread = new Thread(null, viewOrders, "MagentoBackground");
thread.start();
m_ProgressDialog = ProgressDialog.show(SplashScreenActivity.this, "Please wait...", "Getting required data from server. This is an one time activity...", true);
}
public void updateUI(int code){
Log.i(UtilityFunctions.APP_TAG, "updateUI");
if(code == 0)
Toast.makeText(SplashScreenActivity.this, "Unable to verify application signature. Please Check your internet connection & try again", Toast.LENGTH_LONG).show();
else
Toast.makeText(SplashScreenActivity.this, "Unable to process request. ", Toast.LENGTH_LONG).show();
}