的setMessage()空指針異常我試圖延長ProgressDialog類來創建我的自定義對話框。當我嘗試執行以下實現。這是給空指針異常的setmessage()調用在定製的Android對話框
可有人請解釋如何做呢?
private class SubProgressDialog extends ProgressDialog {
Textview tvdialogtext;
public SubProgressDialog(Context context) {
super(context);
}
@Override
public void setMessage(CharSequence message) {
// TODO Auto-generated method stub
tvdialogtext.setText(message);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.loadingdialog);
tvdialogtext = (TextView) dialog.findViewById(R.id.tvloading);
Typeface ttf = Typeface.createFromAsset(this.getContext()
.getAssets(), "calibriitalic.ttf");
ImageView ivloading = (ImageView) dialog
.findViewById(R.id.ivloading);
ivloading.setBackgroundResource(R.animator.loading);
AnimationDrawable anim = (AnimationDrawable) ivloading
.getBackground();
anim.start();
anim.setVisible(true,true);
tvdialogtext.setTypeface(ttf);
tvdialogtext.setTextColor(Color.parseColor("#ffffff"));
tvdialogtext.setShadowLayer(25f, 0, 0, Color.WHITE);
}
@Override
public void onBackPressed() {
/** dismiss the progress bar and clean up here **/
if (dialog != null) {
dialog.dismiss();
}
running = false;
finish();
help.comeinfromleft();
}
}
logcat的
09-28 21:17:48.154: E/AndroidRuntime(27745): Caused by: java.lang.NullPointerException
09-28 21:17:48.154: E/AndroidRuntime(27745): at m sfs com.anshul.guessthegaana.OnePlayerArena$SubProgressDialog.setMessage(OnePlayerArena.java:1552)
09-28 21:17:48.154: E/AndroidRuntime(27745): at com.anshul.guessthegaana.OnePlayerArena$GetSongsFromServer.onPreExecute(OnePlayerArena.java:1 191)
09-28 21:17:48.154: E/AndroidRuntime(27745): at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
09-28 21:17:48.154: E/AndroidRuntime(27745): at android.os.AsyncTask.execute(AsyncTask.java:534)
09-28 21:17:48.154: E/AndroidRuntime(27745): at com.anshul.guessthegaana.OnePlayerArena.onCreate(OnePlayerArena.java:247)
09-28 21:17:48.154: E/AndroidRuntime(27745): at android.app.Activity.performCreate(Activity.java:5165)
09-28 21:17:48.154: E/AndroidRuntime(27745): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1103)
09-28 21:17:48.154: E/AndroidRuntime(27745): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2419)
初始化呼叫
dialog = new SubProgressDialog(this);
dialog.setMessage("Preparing the Game");
dialog.setIndeterminate(false);
dialog.show();
到OnCreate中調用工作正常。 NPE在setmessage()中。仍然給你的解決方案嘗試沒有幫助。添加初始化代碼。 – 2014-09-28 16:55:12