Obsolete
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Comments
al...@gmail.com
[Comment deleted]
al...@gmail.com
This bug has wasted my afternoon and brought out the pedant in me.
Why is the local instance of Context declared as mContext? It's a local variable. According to the code style guidelines, the m prefix is reserved for field names.http://source.android.com/source/code-style.html
Why is the local instance of Context declared as mContext? It's a local variable. According to the code style guidelines, the m prefix is reserved for field names.
ra...@gmail.com
Just as an additional comment: As of now, the shown documentation page is recommending use of the showDialog(int) method, which is deprecated in favor of DialogFragment.
ri...@gmail.com
Error is still there in the documentation. Wasted my evening thinking my view layout was wrong.
am...@gmail.com
It wasted half day effort :(
can some one please update it in the documentation.!!
can some one please update it in the documentation.!!
ma...@gmail.com
This has been fixed already.
sh...@gmail.com
Error is still in some cases when this activity is finished.
ad...@mdtech.us
I get the same thing too!
Code:
protected AlertDialog MsgBox(String title, String mymessage, String PositiveButton, String NegativeButton, final Intent PageToOpen) {
AlertDialog.Builder builder = new AlertDialog.Builder(getBaseContext());
builder.setMessage(mymessage)
.setCancelable(false)
.setTitle(title)
.setPositiveButton(PositiveButton,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
lastMsgBoxResp = 2;
if (PageToOpen != null) {
startActivity(PageToOpen);
}
dialog.cancel();
}
})
.setNegativeButton(NegativeButton,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
lastMsgBoxResp = 1;
// cancel the dialog box
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
// Return the newly created AlertDialog for future use by the calling method.
return alert;
}
Code:
protected AlertDialog MsgBox(String title, String mymessage, String PositiveButton, String NegativeButton, final Intent PageToOpen) {
AlertDialog.Builder builder = new AlertDialog.Builder(getBaseContext());
builder.setMessage(mymessage)
.setCancelable(false)
.setTitle(title)
.setPositiveButton(PositiveButton,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
lastMsgBoxResp = 2;
if (PageToOpen != null) {
startActivity(PageToOpen);
}
dialog.cancel();
}
})
.setNegativeButton(NegativeButton,
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
lastMsgBoxResp = 1;
// cancel the dialog box
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
// Return the newly created AlertDialog for future use by the calling method.
return alert;
}
Description
Please see this article for an explanation:
If you are creating a custom Dialog for Android, and following the Android Developers’ Creating Dialogs tutorial, then most likely you would have faced a Force Close with this exception showing up in logcat. I did too. Although I figured it out quickly, it might not be easy to find out for many, so posting it here for reference. Basically, the code given in the tutorial goes something like this:
Context mContext = getApplicationContext();
Dialog dialog = new Dialog(mContext);
dialog.setContentView(R.layout.custom_dialog);
dialog.setTitle("Custom Dialog");
TextView text = (TextView) dialog.findViewById(R.id.text);
text.setText("Hello, this is a custom dialog!");
ImageView image = (ImageView) dialog.findViewById(R.id.image);
image.setImageResource(
All looks well, but when you execute it, you will get a Force Close. The error appearing in logcat would be something like this:
Uncaught handler: thread main exiting due to uncaught exception
android.view.WindowManager$BadTokenException: Unable to add window — token null is not for an application
It isn’t apparent immediately that what is causing this error. The very first line in the code “Context mContext = getApplicationContext();” is the culprit.
Solution: Just replace “getApplicationContext()” with “this” (i.e. “Context mContext = this;” ) and it will work fine.
Explanation: As to why this is exactly an issue, I’m a bit fuzzy about it myself but this much I’m sure that the contexts that you get with getApplicationContext and this are different. On reading about this function from Android SDK help:
Return the context of the single, global Application object of the current process. This generally should only be used if you need a Context whose lifecycle is separate from the current context, that is tied to the lifetime of the process rather than the current component.
I think this would mean is that getApplicationContext returns a context which is for the application itself and not the activity, while “this” would give you the context of the activity in which you are creating the dialog. I think since it is the activity which is associated with the UI (and for whom the window has been created), using the application context would have caused the crash here.