AlertDialog - HTML

MainActivity.java

package jp.codeforfun.test;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Html;
import android.text.method.LinkMovementMethod;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String message = "Google検索は<br><a href=\"http://google.com\">こちら</a>";

        AlertDialog alert = new AlertDialog.Builder(this)
                .setTitle("タイトル")
                .setMessage(Html.fromHtml(message))
                .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        //「OK」が押された時の処理を書く　
                    }
                })
                .show();
        ((TextView) alert.findViewById(android.R.id.message)).setMovementMethod(LinkMovementMethod.getInstance());
    }
}