How do I display an alert dialog on Android?
How do I display an alert dialog on Android?
Question
I want to display a dialog/popup window with a message to the user that shows "Are you sure you want to delete this entry?" with one button that says 'Delete'. When Delete
is touched, it should delete that entry, otherwise nothing.
I have written a click listener for those buttons, but how do I invoke a dialog or popup and its functionality?
Popular Answer
You could use an AlertDialog
for this and construct one using its Builder
class. The example below uses the default constructor that only takes in a Context
since the dialog will inherit the proper theme from the Context you pass in, but there's also a constructor that allows you to specify a specific theme resource as the second parameter if you desire to do so.
new AlertDialog.Builder(context)
.setTitle("Delete entry")
.setMessage("Are you sure you want to delete this entry?")
// Specifying a listener allows you to take an action before dismissing the dialog.
// The dialog is automatically dismissed when a dialog button is clicked.
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// Continue with delete operation
}
})
// A null listener allows the button to dismiss the dialog and take no further action.
.setNegativeButton(android.R.string.no, null)
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
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Try this code:
AlertDialog.Builder builder1 = new AlertDialog.Builder(context);
builder1.setMessage("Write your message here.");
builder1.setCancelable(true);
builder1.setPositiveButton(
"Yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
builder1.setNegativeButton(
"No",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert11 = builder1.create();
alert11.show();
The code which David Hedlund has posted gave me the error:
Unable to add window — token null is not valid
If you are getting the same error use the below code. It works!!
runOnUiThread(new Runnable() {
@Override
public void run() {
if (!isFinishing()){
new AlertDialog.Builder(YourActivity.this)
.setTitle("Your Alert")
.setMessage("Your Message")
.setCancelable(false)
.setPositiveButton("ok", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// Whatever...
}
}).show();
}
}
});
Just a simple one! Create a dialog method, something like this anywhere in your Java class:
public void openDialog() {
final Dialog dialog = new Dialog(context); // Context, this, etc.
dialog.setContentView(R.layout.dialog_demo);
dialog.setTitle(R.string.dialog_title);
dialog.show();
}
Now create Layout XML dialog_demo.xml
and create your UI/design. Here is a sample one I created for demo purposes:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/dialog_info"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="10dp"
android:text="@string/dialog_text"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_below="@id/dialog_info">
<Button
android:id="@+id/dialog_cancel"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="0.50"
android:background="@color/dialog_cancel_bgcolor"
android:text="Cancel"/>
<Button
android:id="@+id/dialog_ok"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="0.50"
android:background="@color/dialog_ok_bgcolor"
android:text="Agree"/>
</LinearLayout>
</RelativeLayout>
Now you can call openDialog()
from anywhere you like :) Here is the screenshot of above code.
Note that text and color are used from strings.xml
and colors.xml
. You can define your own.
Use AlertDialog.Builder :
AlertDialog alertDialog = new AlertDialog.Builder(this)
//set icon
.setIcon(android.R.drawable.ic_dialog_alert)
//set title
.setTitle("Are you sure to Exit")
//set message
.setMessage("Exiting will call finish() method")
//set positive button
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
//set what would happen when positive button is clicked
finish();
}
})
//set negative button
.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
//set what should happen when negative button is clicked
Toast.makeText(getApplicationContext(),"Nothing Happened",Toast.LENGTH_LONG).show();
}
})
.show();
You will get the following output.
To view alert dialog tutorial use the link below.
Nowadays it's better to use DialogFragment instead of direct AlertDialog creation.