Intent intent = new Intent();
                    ComponentName componet = null;
 componet = new ComponentName("com.android.mms", "com.android.mms.ui.ComposeMessageActivity");
                        intent = new Intent();
                        intent.setComponent(componet);
                        intent.putExtra("mobile", mobile);
                        startActivity(intent);

android:exported="true"    这个属性是运行外面的APP调用