如何在用户在AlertDialog上单击"确定"后启动活动

Intent intent = new Intent(this, TargetActivity.class);

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("AlertDialog");
builder.setMessage("单击“确定”按钮后启动活动");
builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        Intent intent = new Intent(this, TargetActivity.class);
        startActivity(intent);
    }
});
AlertDialog alertDialog = builder.create();
alertDialog.show();