我该如何解决这个错误并转换类型？

Question

我是android编程的初学者.我想写与片段的节目,我阅读本教程(http://www.mysamplecode.com/2012/08/android-fragment-example.html)和写入,但是当我运行程序,程序有编译器错误!错误是关于add()和replace()函数.

我在下面写了AndroidFragmentActivity类,请阅读本文并帮助我.

AndoridFragmentActivity.java:

package com.appfragmentarray;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentActivity;
 import android.util.Log;

import com.appfragmentarray.ListFragment.OnURLSelectedListener;

public class AndroidFragmentActivity extends Activity implements OnURLSelectedListener{
     boolean detailPage = false;

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  Log.v("AndroidFragmentActivity", "onCreate()");
  Log.v("AndroidFragmentsavedInstanceState", savedInstanceState == null ? "true" : "false");

  setContentView(R.layout.activity_main);

  if(savedInstanceState == null) {
   android.app.FragmentTransaction ft = getFragmentManager().beginTransaction();
   ListFragment listFragment = new ListFragment();
   ft.add(R.id.displayList, listFragment, "List_Fragment");
   ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
   ft.commit();
  }

  if(findViewById(R.id.displayDetail) != null){
   detailPage = true;
   getFragmentManager().popBackStack();

   DetailFragment detailFragment = (DetailFragment) getFragmentManager().findFragmentById(R.id.displayDetail);
   if(detailFragment == null){
    android.app.FragmentTransaction ft = getFragmentManager().beginTransaction();
    detailFragment = new DetailFragment();
    ft.replace(R.id.displayDetail, detailFragment, "Detail_Fragment1");
    ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
    ft.commit();
   }
  }

 }


 public void onURLSelected(String URL) {
  Log.v("AndroidFragmentActivity",URL);

  if(detailPage){
   DetailFragment detailFragment = (DetailFragment)
   getFragmentManager().findFragmentById(R.id.displayDetail);
   detailFragment.updateURLContent(URL);
  }
  else{
   DetailFragment detailFragment = new DetailFragment();
   detailFragment.setURLContent(URL);
   android.app.FragmentTransaction ft = getFragmentManager().beginTransaction();
   ft.replace(R.id.displayList, detailFragment, "Detail_Fragment2");
   ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
   ft.addToBackStack(null);
   ft.commit();
  }
 }


  }

错误是:

无法从Fragment转换为DetailFragment

在类型FragmentTransaction的方法Add(INT,片段,字符串)是不适用的参数(INT,ListFragment,字符串)

该方法在类型FragmentTransaction替换(INT,片段,字符串)是不适用的参数(INT,DetailFragment,字符串)

我该如何解决这个问题？谢谢.

Answer 1

您可能正在混合兼容性片段和正常的3.0+ 片段类.

如果要使用兼容包:

请AndroidFragmentActivity延长FragmentActivity

更改

android.app.FragmentTransaction ft = getFragmentManager().beginTransaction();

至

FragmentTransaction ft = getSupportFragmentManager().beginTransaction();

并确保所有的电话getFragmentManager()都是getSupportFragmentManager()

确保你的碎片延伸android.support.v4.app.Fragment而不是android.app.Fragment

要么

如果你想使用普通的碎片,摆脱所有的support.v4进口,并确保你的碎片使用android.app.Fragment,这是不兼容的碎片.