比如 transaction.add(R.id.content, waitLookFragment);
add方法没有方法体, 那为什么该方法有实现功能,我好像也没找到什么类继承了FragmentTransactino
import android.support.v4.app.Fragment;
public abstract class FragmentTransaction {
......
......
.....
public FragmentTransaction() {
}
public abstract FragmentTransaction add(Fragment var1, String var2);
public abstract FragmentTransaction add(int var1, Fragment var2);
public abstract FragmentTransaction add(int var1, Fragment var2, String var3);