解决Android ListView数据为空及加载错误的方法

在项目中，都会用到ListView或GridView等列表控件。一般会用来展示从网络请求的数据 。如果请求的数据为空或者在请求的时候正好无没有网络了，我们的界面应该如何展示呢？数据为空的时候,ListView可以使用setEmptyView (View emptyView) 方法来我们需要的统一界面。数据加载失败呢？我们也可以统一进行处理。

//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

 
 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;
 }

 
 public void setEmptyOrErrorView(ViewGroup emptyOrErrorView) {
  this.mParentView.removeView(this.mEmptyOrErrorView);
  this.mParentView.addView(emptyOrErrorView, mLayoutParams);
  this.mEmptyOrErrorView = emptyOrErrorView;
 }

 
 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;
 }

 
 public ViewGroup getContextView() {
  return mContentView;
 }

 
 public ViewGroup getRootView() {
  return mParentView;
 }

 
 public void setContextView(ViewGroup contentView) {
  this.mType = TYPE_CONTENT;
  showByType(mType);
 }

 
 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;
   }
  }
 }

 
 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



 

 

//在Activity中使用
public class MainActivity extends Activity {
 private ListView listview;
 private CommonShowView mShowView;
 private List 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 getDatas(boolean flag) {
  List 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 datas;
  private Context mContext;

  public MyAdapter(Context mContext, List 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;
  }

 }
}

目前只是做了个超级简单的样式，具体的展示根据需求再改再封装。帖个图：

以上就是ListView数据为空及加载错误处理的方法，希望对大家的学习有所帮助。