第9篇.Fragment相关

一、主要是描述下大致的使用步骤，主要是分三个部分，fragment部分、activity部分，两者通信部分
1、Fragment部分，这个部分从某种角度上来说是独立于activity的，这也就是fragment的优势，主要是给这个fragment找到一个layout，并找到他上面的控件，简单事例如下：

public class ImgPreviewFragment extends Fragment{

private View Pre_View;
private TextView NumRatio;
private ImageView TypeImg;
private TextView SourceName;
private LinearLayout VideoLayout;

private ImageButton Pre;
private ImageButton Play;
private ImageButton Next;
private ImageButton ToImageView;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View view = inflater.inflate(R.layout.lexus_img_preview, container, false);
Pre_View = (View)view.findViewById(R.id.img_pre_info_layout);
findView();
setOnClick();
return view;
}

2、Activity部分，要在activity所在的layout.xml里面建立一个容器（就是一个布局），之后创建fragment对象，并把fragment对象导入到容器当中去即可

主要代码如下 ，思路为创建fragment管理器，增加删除fragment，显示和隐藏fragment：

private FragmentManager mFragmentManager;
private ImgPreviewFragment mImgPreviewFragment;
void ShowOrHidePreviewFragment(boolean show){
mFragmentManager = getFragmentManager();
FragmentTransaction transaction = mFragmentManager.beginTransaction();
if(mImgPreviewFragment == null){
mImgPreviewFragment = new ImgPreviewFragment();
}
if(show){
transaction.show(mImgPreviewFragment);
mImgPreviewFragment.SetHandler(myHandler);
transaction.commit();
}else{
transaction.hide(mImgPreviewFragment);
mImgPreviewFragment.SetHandler(null);
transaction.commit();

}
}

void AddOrRemovePreviewFragment(boolean add){
mFragmentManager = getFragmentManager();
FragmentTransaction transaction = mFragmentManager.beginTransaction();
if(mImgPreviewFragment == null){
mImgPreviewFragment = new ImgPreviewFragment();
}
if(add){
transaction.add(R.id.img_preview_content,mImgPreviewFragment);
}else{
transaction.remove(mImgPreviewFragment);
}
transaction.commit();
}


3、Activity和fragment之间的通信

Activity 到fragment，直接使用fragment对象的函数即可，fragment到Activity，一般是使用handler来进行，该handler由activity传递到fragment去