1、无弹框（利用反射）

public static final String CLASS_SMS_MANAGER = "com.android.internal.telephony.SmsApplication";

public static final String METHOD_SET_DEFAULT = "setDefaultApplication";

private void setDefaultSms(Boolean isMyApp) {

try {

Class smsClass = Class.forName(CLASS_SMS_MANAGER);

Method method = smsClass.getMethod(METHOD_SET_DEFAULT, String.class, Context.class);

method.invoke(null, "要设置的包名", this);

} catch (Exception e) {

e.printStackTrace();

}

}

2、有弹窗

Intent intent = new Intent(Telephony.Sms.Intents.ACTION_CHANGE_DEFAULT);

intent.putExtra(Telephony.Sms.Intents.EXTRA_PACKAGE_NAME, "要设置的包名");

startActivity(intent);