Develop Reference

How to Keep showing the dialog when the Activity is change

I used a custom dialog as a notify in the app, so I want it to keep show even the activity is changing, can it? or I should use other thing?

Use getApplicationContext().
AlertDialog.Builder builder = new AlertDialog.Builder(getApplicationContext());

Making a button appear in Android when a condition is fulfilled

As the title says I'd like to know the best method for generating a button upon some condition being fulfilled in my code. In this case, I'd like clicking on a particular imageView "s02" to make a button appear in my activity.
I know that you can make AlertDialogs appear using code like this:
AlertDialog alertDialog = new AlertDialog.Builder(this).create();
alertDialog.setTitle("Title");
alertDialog.setMessage("Message");
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// code code code code code }
});
I tried substituting Button for AlertDialog on the first line but I couldn't use Builder on Button.
Also, should I create the button in a separate section of code then simply make it appear when the condition is set, or should I put the button's functionality in the code creating the button?

Putting your button in the xml layout and just making it appear when needed is the easiest route. If that isn't good enough, you can create a Button via new Button(Context), set all the parameters you need, then add it to the parent layout.

Display Android dialog on top of another?

I have 2 alert dialogs, dialog A and dialog B. Clicking on one of dialog A's buttons will bring up dialog B. I then want to have a button that will dismiss dialog B and return to dialog A.
Is there a way to do this apart from dialog B performing a showDialog(dialogA) ?
This works, but you can see the reload of dialog A, instead of just returning to an already existing dialog A. Performing a dismiss in dialog B just dismisses both of them.
A minor question, but I'd like to see if there is a way to stack them on top of one another.
Thanks

Using the basic dialog building blocks it is not possible to have them stack, you will need to re-show the first dialog.
The reason for this is that when you press a dialog button it internally will dismiss the dialog as part of the process for calling the click handler you assigned for each button in the dialog builder API.
One way around this is to make a custom dialog layout that doesn't have the dismiss behavior, by setting up your own buttons in the layout, rather than using those created by the dialog builder methods. Then in the click handler for you own buttons simply show the second dialog without dismissing the first.
http://developer.android.com/guide/topics/ui/dialogs.html#CustomDialog

As one reply mentioned, you cannot do this with standard dialogs. But you can do it by making the first dialog be an activity that is styled to look like a dialog, and the second is actually a dialog.
Just set the theme of the activity in your layout like so:
<activity android:theme="#android:style/Theme.Dialog">
See this topic on making an activity that looks like a dialog.
https://stackoverflow.com/a/1979631/602661

dismiss the dialog from within itself.
Edit, here is some clearer code.
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
return;
}
});
alertDialog.show();

You should use inside your custom layout one view/button and based on this view/button click you can create another dailog without cancel first one, if you use builder.setNegativeButton or builder.setPositiveButton your current dialog will be close, my working code like as,
AlertDialog.Builder builder = new AlertDialog.Builder(ActivityAppImages.this,R.style.your_style);
LayoutInflater inflater = getLayoutInflater();
View dialoglayout = inflater.inflate(R.layout.your_custom_layout, null);
final Button mButtonCreateOtherDailog = (Button)dialoglayout.findViewById(R.id.txt_create_second_dailog);
mTextView.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//create your other dailog here
}
});
builder.setView(dialoglayout);
builder.show();

Enter data in an Android popup

I want the user to enter a string into an EditText into a popup. I have taken a look in Android Developers here .
But this kind of popup is not explained. How can I make it?

On the same page you linked to, check out how they say to create a custom dialog.
Create an XML layout for the dialog that has an EditText. Then show it:
Context mContext = getApplicationContext();
Dialog dialog = new Dialog(mContext);
dialog.setContentView(R.layout.custom_dialog);
dialog.setTitle("Custom Dialog");
dialog.show();

Create your own custom dialog by extending Dialog. Your custom dialog class will have an onCreate() callback, in which you can call setContentView to whatever view you want, just like with an Activity.
Simply create a view to look however you'd like and use that one. Then, when you want to use your dialog, simply get an instance, like Dialog myDialog = new MyCustomDialog(getParent(), R.style.some_style); and then myDialog.show();

Android Class which extends Dialog, how to clear TextViews before it is displayed

I have a class that extends android.app.Dialog, the layout is done in an xml file, and the setup (button listeners, etc) is done on the onCreate method. My problem is that whenever the dialog is displayed, then dismissed, and displayed again, the Editable TextViews are still populated with the information that was displayed previously. What is the common way to clear these text fields? Remember - this is a separate class that extends Dialog - so there is no 'onDialogCreate' like Activity has.
Or, perhaps I am extending the wrong class? There is just a lot of processing being done, and do not want to have all the code in the main Activity. I would like it to be in a separate Class. I tried to extend AlertDialog, but it does not create the border like Dialog does. Any help would be great.
The dialog is shown via the Activity:
protected Dialog onCreateDialog(int id) {
switch(id){
case DIALOG_NEW_SAFE:
return(new NewSafeDialog(this));
default:
return(null);
}
}

onCreateDialog(..) caches the dialog which means the same instance is reused.
3 ways to fix the undesired behavior off my head:
Override onPrepareDialog(..), use findViewById(..) to get whatever you want to clear, clear it.
Don't rely on managed dialogs at all, do new NewSafeDialog(this).show() each time you want to show the dialog.
Add onCancelListener(..), onDismissListener(..) inside your custom dialog that would call a method to clear itself.

The good way to create a dialog is by using showDialog() as you did so don't change it.
The good and easy way to force deletion of a dialog in order to make your creation code recalled again is:
void removeDialog (int id)
So if you simply do the following, it's gonna work ;)
removeDialog(DIALOG_NEW_SAFE);
showDialog(DIALOG_NEW_SAFE);

Try clearing the text in the constructor of the NewSafeDialog i.e. your dialog class.