解决Android ListView数据为空及加载错误的方法

//下面这个类是简单地封装用于无数据及加载错误的一个页面。public class CommonShowView { private Context mContext;// 上下文 private ViewGroup mEmptyOrErrorView;// 页面加载无数据或加载错误时显示 private ViewGroup mContentView;// 加载成功时显示的内容 private ViewGroup mParentView;// 父布局viewGroup private LayoutInflater mInflater; private TextView no_net; private Button load_btn; private boolean mViewsAdded; private ViewGroup.LayoutParams mLayoutParams = new ViewGroup.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); public final static int TYPE_EMPTY = 1;// 数据为空 public final static int TYPE_ERROR = 2;// 加载数据失败 public final static int TYPE_CONTENT = 3;// 直接显示内容 private int mType = TYPE_EMPTY;// 数据类型，默认是无数据 /**  * 构造方法，传入上下文及内容GroupView  */ public CommonShowView(Context context, ViewGroup mContentView) {  mContext = context;  mInflater = LayoutInflater.from(mContext);  this.mContentView = mContentView;  mParentView = (ViewGroup) mContentView.getParent();  initViews(); } @SuppressLint("InflateParams") private void initViews() {  mEmptyOrErrorView = (ViewGroup) mInflater.inflate(R.layout.common_show, null);  no_net = (TextView) mEmptyOrErrorView.findViewById(R.id.no_net);  load_btn = (Button) mEmptyOrErrorView.findViewById(R.id.load_btn);  if (!mViewsAdded) {   mViewsAdded = true;   mParentView.addView(mEmptyOrErrorView, mLayoutParams);  }  load_btn.setOnClickListener(new OnClickListener() {// 检查网络，进行网络设置   @Override   public void onClick(View v) {    Intent intent = null;    // 判断手机系统的版本 即API大于10 就是3.0或以上版本及魅族手机    if (android.os.Build.VERSION.SDK_INT > 10 && !android.os.Build.MANUFACTURER.equals("Meizu")) {     intent = new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS);    }    else if (android.os.Build.VERSION.SDK_INT > 17 && android.os.Build.MANUFACTURER.equals("Meizu")) {     intent = new Intent(android.provider.Settings.ACTION_SETTINGS);    }    else {     intent = new Intent();     ComponentName component = new ComponentName("com.android.settings", "com.android.settings.WirelessSettings");     intent.setComponent(component);     intent.setAction("android.intent.action.VIEW");    }    mContext.startActivity(intent);   }  }); } public ViewGroup getEmptyOrErrorView() {  return mEmptyOrErrorView; } /**  * 设置无数据或加载错误view  * @description：  */ public void setEmptyOrErrorView(ViewGroup emptyOrErrorView) {  this.mParentView.removeView(this.mEmptyOrErrorView);  this.mParentView.addView(emptyOrErrorView, mLayoutParams);  this.mEmptyOrErrorView = emptyOrErrorView; } /**  * 设置无数据或加载错误view  * @description：  */ public void setEmptyOrErrorView(int res) {  ViewGroup vg = (ViewGroup) mInflater.inflate(res, null);  this.mParentView.removeView(this.mEmptyOrErrorView);  this.mParentView.addView(vg, mLayoutParams);  this.mEmptyOrErrorView = vg; } /**  * 获取内容view  * @description：  */ public ViewGroup getContextView() {  return mContentView; } /**  * 方法概述：获取内容View的父布局  */ public ViewGroup getRootView() {  return mParentView; } /**  * 方法概述：设置展示内容的视图  */ public void setContextView(ViewGroup contentView) {  this.mType = TYPE_CONTENT;  showByType(mType); } /**  * 根据类型进行对应展示   * @description：  * @date 2016-2-19 下午3:02:20  */ public void showByType(int mType) {  hideAllViews();  if (mContentView != null) {   switch (mType) {    case TYPE_EMPTY:     if (mEmptyOrErrorView != null) {      mEmptyOrErrorView.setVisibility(View.VISIBLE);      no_net.setText("这里空空也野哦~");      load_btn.setVisibility(View.GONE);     }     break;    case TYPE_ERROR:     if (mEmptyOrErrorView != null) {      mEmptyOrErrorView.setVisibility(View.VISIBLE);      no_net.setText("网络加载失败哦~");      load_btn.setVisibility(View.VISIBLE);     }     break;    case TYPE_CONTENT:     if (mContentView != null) {      mContentView.setVisibility(View.VISIBLE);     }     break;    default:     break;   }  } } /**  * 方法概述：将所有的子View隐藏起来  */ private void hideAllViews() {  if (mParentView != null) {   if (mParentView.getChildCount() > 0) {    for (int i = 0; i < mParentView.getChildCount(); i++) {     View childView = mParentView.getChildAt(i);     if (childView != null) {      childView.setVisibility(View.GONE);     }    }   }  } }}

//错误页面及空页面时布局<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/rel_null" android:layout_width="match_parent" android:layout_height="match_parent" > <TextView  android:id="@+id/no_net"  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:layout_centerHorizontal="true"  android:layout_centerInParent="true"  android:gravity="center"  android:text="好像没网哦~"  android:textColor="#333333"  android:textSize="16sp" /> <Button  android:id="@+id/load_btn"  android:layout_width="112dp"  android:layout_height="40dp"  android:layout_below="@+id/no_net"  android:layout_centerHorizontal="true"  android:layout_marginTop="15dp"  android:background="#E12228"  android:gravity="center"  android:text="检查网络"  android:textColor="#ffffff"  android:textSize="14sp" /></RelativeLayout>

//在Activity中使用public class MainActivity extends Activity { private ListView listview; private CommonShowView mShowView; private List<String> datas; @Override protected void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);  setContentView(R.layout.activity_main);  listview = (ListView) findViewById(R.id.listview);  mShowView = new CommonShowView(this, listview);  // ----------有数据的时情况下--------------  // datas = getDatas(true);  // listview.setAdapter(new MyAdapter(this, datas));  // mShowView.setContextView(listview);//显示数据，也可以不调用，直接显示  // --------无数据的情况下----------------  // datas = getDatas(false);//无数据  // mShowView.showByType(CommonShowView.TYPE_EMPTY);  // ---------数据加载失败的情况下---------------  mShowView.showByType(CommonShowView.TYPE_ERROR); } private List<String> getDatas(boolean flag) {  List<String> datas = new ArrayList<>();  datas.add("这是第一行的data");  datas.add("这是第2行的data");  datas.add("这是第三行的data");  datas.add("这是第4行的data");  if (flag) {   return datas;  }  else {   return null;  } } class MyAdapter extends BaseAdapter {  private List<String> datas;  private Context mContext;  public MyAdapter(Context mContext, List<String> datas) {   this.mContext = mContext;   this.datas = datas;  }  @Override  public int getCount() {   // TODO Auto-generated method stub   return datas.size();  }  @Override  public Object getItem(int position) {   // TODO Auto-generated method stub   return datas.get(position);  }  @Override  public long getItemId(int position) {   // TODO Auto-generated method stub   return position;  }  @Override  public View getView(int position, View convertView, ViewGroup parent) {   // 这里只举个小例子，没有考虑性能 优化   TextView tv = new TextView(mContext);   tv.setTextSize(16f);   tv.setText(datas.get(position));   return tv;  } }}