Android listview Android listview数据显示及提示信息的实例

package com.tianjs.tianjinsuop2p.widgets;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.widget.Adapter;
import android.widget.ListView;

import com.tianjs.tianjinsuop2p.R;

/**
 * Created by xiaolei on 2017/4/28.
 */

public class NoDataListView extends ListView
{
  private int height = 0;
  private int width = 0;
  private Bitmap noDataBitmap = null;
  private Paint mPaint;

  private int minItem = 0;
  private int noDataImgInt = 0;

  public NoDataListView(Context context)
  {
    this(context, null);
  }

  public NoDataListView(Context context, AttributeSet attrs)
  {
    this(context, attrs, 0);
  }

  public NoDataListView(Context context, AttributeSet attrs, int defStyleAttr)
  {
    super(context, attrs, defStyleAttr);
    TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.NoDataListView);

    noDataImgInt = array.getResourceId(R.styleable.NoDataListView_noDataImg, 0);
    minItem = array.getInt(R.styleable.NoDataListView_minItem, 0);

    if (noDataImgInt != 0)
    {
      noDataBitmap = BitmapFactory.decodeResource(getResources(), noDataImgInt);
    } else
    {
      noDataBitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888);
    }
    mPaint = new Paint();

    array.recycle();
  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
  {
    height = MeasureSpec.getSize(heightMeasureSpec);
    width = MeasureSpec.getSize(widthMeasureSpec);
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
  }

  @Override
  protected void onDraw(Canvas canvas)
  {
    Adapter adapter = getAdapter();
    super.onDraw(canvas);
    if (adapter == null || adapter.getCount() <= minItem)
    {
      canvas.drawBitmap(noDataBitmap, width / 2 - noDataBitmap.getWidth() / 2, height / 2 - noDataBitmap.getHeight() / 2, mPaint);
    }
  }
}

<declare-styleable name="NoDataListView">
  <!--最低Item数-->
  <attr name="minItem" format="integer"/>
  <!--没有数据时，显示的图片资源-->
  <attr name="noDataImg" format="reference"/>
</declare-styleable>

<com.tianjs.tianjinsuop2p.widgets.NoDataListView
      android:id="@+id/listview"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:divider="#00000000"
      android:dividerHeight="0dp"
      android:overScrollMode="never"
      android:scrollbars="none"
      app:minItem="0"
      app:noDataImg="@drawable/icon_wushuju"/>