I don\'t make alerts very often but every time I do it takes me a while to read through the documentation and figure out how to do it. Since I have had to do this a few time
import android.support.v7.app.AlertDialog;
public class MainActivity extends AppCompatActivity {
public void showAlertDialogButtonClicked(View view) {
// setup the alert builder
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("My title");
builder.setMessage("This is my message.");
// add a button
builder.setPositiveButton("OK", null);
// create and show the alert dialog
AlertDialog dialog = builder.create();
dialog.show();
}
}
public class MainActivity extends AppCompatActivity {
public void showAlertDialogButtonClicked(View view) {
// setup the alert builder
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("AlertDialog");
builder.setMessage("Would you like to continue learning how to use Android alerts?");
// add the buttons
builder.setPositiveButton("Continue", null);
builder.setNegativeButton("Cancel", null);
// create and show the alert dialog
AlertDialog dialog = builder.create();
dialog.show();
}
}
public class MainActivity extends AppCompatActivity {
public void showAlertDialogButtonClicked(View view) {
// setup the alert builder
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Notice");
builder.setMessage("Launching this missile will destroy the entire universe. Is this what you intended to do?");
// add the buttons
builder.setPositiveButton("Launch missile", null);
builder.setNeutralButton("Remind me later", null);
builder.setNegativeButton("Cancel", null);
// create and show the alert dialog
AlertDialog dialog = builder.create();
dialog.show();
}
}
If the button text it too long to all fit horizontally, then it will automatically get laid out in a vertical column of three buttons.
The OnClickListener
was null
in the above examples. You can replace null
with a listener to do something when the user taps a button. For example:
builder.setPositiveButton("Launch missile", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// do something like...
launchMissile();
}
});
There are many more varieties of dialogs that you can make. See the documentation for help with this.
Since only three buttons are supported in an AlertDialog
, here is an example of a dialog with a list.
public class MainActivity extends AppCompatActivity {
public void showAlertDialogButtonClicked(View view) {
// setup the alert builder
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Choose an animal");
// add a list
String[] animals = {"horse", "cow", "camel", "sheep", "goat"};
builder.setItems(animals, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
switch (which) {
case 0: // horse
case 1: // cow
case 2: // camel
case 3: // sheep
case 4: // goat
}
}
});
// create and show the alert dialog
AlertDialog dialog = builder.create();
dialog.show();
}
}
See this answer for similar examples of a radio button list and a checkbox list.
DialogFragment
for easy reuse of a dialog. (See this for help.)These examples used the support library to support versions prior to API 11. So the import should be
import android.support.v7.app.AlertDialog;
I omitted the onCreate
method in the examples above for brevity. There was nothing special there.