ListView中加入LinearLayout【二】
这个主要是补充《ListView中加入LinearLayout【一】》中的一些限制
在【一】 中，我试了很多方法添加网络上的图片，在无数次失败后，终于成功添加。
{此方法不建议使用 要用listView建议重写BaseAdapter的getView方法 自己想怎么定义Adapter就怎么定义 就不用费这么大的周折了-----2011.11.23
}
这个就要用到Android的API源码，我改写了下SimpleAdapter这个类（主要是重写一个setViewImage方法）。并命名为MyAdapter.java
另外添加了一个把URL资源转换成BitMap图像的类
代码如下：
/**
* Class Name: UrlToBitmap
* @author Pweibo
* Turn an Url image to Bitmap type
*/
public class UrlToBitmap {
private Bitmap bitmap;
/**
*
* @param myFileUrl An image of URL type
*/
public UrlToBitmap(URL myFileUrl) {
// URL myFileUrl = null;
bitmap = null;
try {
HttpURLConnection conn = (HttpURLConnection) myFileUrl.openConnection();
conn.setDoInput(true);
conn.connect();
InputStream is = conn.getInputStream();
bitmap = BitmapFactory.decodeStream(is);
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
*
* @return A Bitmap type
*/
public Bitmap reutrnBitmap(){
return bitmap;
}
}
/**
* Class Name: MyAdapter
* @author Pcd
* </br>rewriting code from SimpleAdapter
*
*/
public class MyAdapter extends BaseAdapter implements Filterable {
private int[] mTo;
private String[] mFrom;
private ViewBinder mViewBinder;
private List<? extends Map<String, ?>> mData;
private int mResource;
private int mDropDownResource;
private LayoutInflater mInflater;
private SimpleFilter mFilter;
private ArrayList<Map<String, ?>> mUnfilteredData;
/**
* Constructor
*
* @param context The context where the View associated with this SimpleAdapter is running
* @param data A List of Maps. Each entry in the List corresponds to one row in the list. The
* Maps contain the data for each row, and should include all the entries specified in
* "from"
* @param resource Resource identifier of a view layout that defines the views for this list
* item. The layout file should include at least those named views defined in "to"
* @param from A list of column names that will be added to the Map associated with each
* item.
* @param to The views that should display column in the "from" parameter. These should all be
* TextViews. The first N views in this list are given the values of the first N columns
* in the from parameter.
*/
public MyAdapter(Context context, List<? extends Map<String, ?>> data,
int resource, String[] from, int[] to) {
mData = data;
mResource = mDropDownResource = resource;
mFrom = from;
mTo = to;
mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
/**
* @see android.widget.Adapter#getCount()
*/
public int getCount() {
return mData.size();
}
/**
* @see android.widget.Adapter#getItem(int)
*/
public Object getItem(int position) {
return mData.get(position);
}
/**
* @see android.widget.Adapter#getItemId(int)
*/
public long getItemId(int position) {
return position;
}
/**
* @see android.widget.Adapter#getView(int, View, ViewGroup)
*/
public View getView(int position, View convertView, ViewGroup parent) {
return createViewFromResource(position, convertView, parent, mResource);
}
private View createViewFromResource(int position, View convertView,
ViewGroup parent, int resource) {
View v;
if (convertView == null) {
v = mInflater.inflate(resource, parent, false);
} else {
v = convertView;
}
bindView(position, v);
return v;
}
/**
* <p>Sets the layout resource to create the drop down views.</p>
*
* @param resource the layout resource defining the drop down views
* @see #getDropDownView(int, android.view.View, android.view.ViewGroup)
*/
public void setDropDownViewResource(int resource) {
this.mDropDownResource = resource;
}
@Override
public View getDropDownView(int position, View convertView, ViewGroup parent) {
return createViewFromResource(position, convertView, parent, mDropDownResource);
}
private void bindView(int position, View view) {
final Map dataSet = mData.get(position);
if (dataSet == null) {
return;
}
final ViewBinder binder = mViewBinder;
final String[] from = mFrom;
final int[] to = mTo;
final int count = to.length;
for (int i = 0; i < count; i++) {
final View v = view.findViewById(to[i]);
if (v != null) {
final Object data = dataSet.get(from[i]);
String text = data == null ? "" : data.toString();
if (text == null) {
text = "";
}
boolean bound = false;
if (binder != null) {
bound = binder.setViewValue(v, data, text);
}
if (!bound) {
if (v instanceof Checkable) {
if (data instanceof Boolean) {
((Checkable) v).setChecked((Boolean) data);
} else if (v instanceof TextView) {
// Note: keep the instanceof TextView check at the bottom of these
// ifs since a lot of views are TextViews (e.g. CheckBoxes).
setViewText((TextView) v, text);
} else {
throw new IllegalStateException(v.getClass().getName() +
" should be bound to a Boolean, not a " +
(data == null ? "<unknown type>" : data.getClass()));
}
} else if (v instanceof TextView) {
// Note: keep the instanceof TextView check at the bottom of these
// ifs since a lot of views are TextViews (e.g. CheckBoxes).
setViewText((TextView) v, text);
} else if (v instanceof ImageView) {
if (data instanceof Integer) {
setViewImage((ImageView) v, (Integer) data);
} else if(data instanceof Bitmap){
setViewImage((ImageView) v, (Bitmap) data);
}
else {
setViewImage((ImageView) v, text);
}
} else {
throw new IllegalStateException(v.getClass().getName() + " is not a " +
" view that can be bounds by this SimpleAdapter");
}
}
}
}
}
/**
* Returns the {@link ViewBinder} used to bind data to views.
*
* @return a ViewBinder or null if the binder does not exist
*
* @see #setViewBinder(android.widget.SimpleAdapter.ViewBinder)
*/
public ViewBinder getViewBinder() {
return mViewBinder;
}
/**
* Sets the binder used to bind data to views.
*
* @param viewBinder the binder used to bind data to views, can be null to
* remove the existing binder
*
* @see #getViewBinder()
*/
public void setViewBinder(ViewBinder viewBinder) {
mViewBinder = viewBinder;
}
public void setViewImage(ImageView v, Bitmap bm) {
try {
v.setImageBitmap(bm);
} catch (Exception e ) {
System.err.print("Erro in ViewImage");
}
}
/**
* Called by bindView() to set the image for an ImageView but only if
* there is no existing ViewBinder or if the existing ViewBinder cannot
* handle binding to an ImageView.
*
* This method is called instead of {@link #setViewImage(ImageView, String)}
* if the supplied data is an int or Integer.
*
* @param v ImageView to receive an image
* @param value the value retrieved from the data set
*
* @see #setViewImage(ImageView, String)
*/
public void setViewImage(ImageView v, int value) {
v.setImageResource(value);
}
/**
* Called by bindView() to set the image for an ImageView but only if
* there is no existing ViewBinder or if the existing ViewBinder cannot
* handle binding to an ImageView.
*
* By default, the value will be treated as an image resource. If the
* value cannot be used as an image resource, the value is used as an
* image Uri.
*
* This method is called instead of {@link #setViewImage(ImageView, int)}
* if the supplied data is not an int or Integer.
*
* @param v ImageView to receive an image
* @param value the value retrieved from the data set
*
* @see #setViewImage(ImageView, int)
*/
public void setViewImage(ImageView v, String value) {
try {
v.setImageResource(Integer.parseInt(value));
} catch (NumberFormatException nfe) {
v.setImageURI(Uri.parse(value));
}
}
/**
* Called by bindView() to set the text for a TextView but only if
* there is no existing ViewBinder or if the existing ViewBinder cannot
* handle binding to an TextView.
*
* @param v TextView to receive text
* @param text the text to be set for the TextView
*/
public void setViewText(TextView v, String text) {
v.setText(text);
}
public Filter getFilter() {
if (mFilter == null) {
mFilter = new SimpleFilter();
}
return mFilter;
}
/**
* This class can be used by external clients of SimpleAdapter to bind
* values to views.
*
* You should use this class to bind values to views that are not
* directly supported by SimpleAdapter or to change the way binding
* occurs for views supported by SimpleAdapter.
*
* @see SimpleAdapter#setViewImage(ImageView, int)
* @see SimpleAdapter#setViewImage(ImageView, String)
* @see SimpleAdapter#setViewText(TextView, String)
*/
public static interface ViewBinder {
/**
* Binds the specified data to the specified view.
*
* When binding is handled by this ViewBinder, this method must return true.
* If this method returns false, SimpleAdapter will attempts to handle
* the binding on its own.
*
* @param view the view to bind the data to
* @param data the data to bind to the view
* @param textRepresentation a safe String representation of the supplied data:
* it is either the result of data.toString() or an empty String but it
* is never null
*
* @return true if the data was bound to the view, false otherwise
*/
boolean setViewValue(View view, Object data, String textRepresentation);
}
/**
* <p>An array filters constrains the content of the array adapter with
* a prefix. Each item that does not start with the supplied prefix
* is removed from the list.</p>
*/
private class SimpleFilter extends Filter {
@Override
protected FilterResults performFiltering(CharSequence prefix) {
FilterResults results = new FilterResults();
if (mUnfilteredData == null) {
mUnfilteredData = new ArrayList<Map<String, ?>>(mData);
}
if (prefix == null || prefix.length() == 0) {
ArrayList<Map<String, ?>> list = mUnfilteredData;
results.values = list;
results.count = list.size();
} else {
String prefixString = prefix.toString().toLowerCase();
ArrayList<Map<String, ?>> unfilteredValues = mUnfilteredData;
int count = unfilteredValues.size();
ArrayList<Map<String, ?>> newValues = new ArrayList<Map<String, ?>>(count);
for (int i = 0; i < count; i++) {
Map<String, ?> h = unfilteredValues.get(i);
if (h != null) {
int len = mTo.length;
for (int j=0; j<len; j++) {
String str = (String)h.get(mFrom[j]);
String[] words = str.split(" ");
int wordCount = words.length;
for (int k = 0; k < wordCount; k++) {
String word = words[k];
if (word.toLowerCase().startsWith(prefixString)) {
newValues.add(h);
break;
}
}
}
}
}
results.values = newValues;
results.count = newValues.size();
}
return results;
}
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
//noinspection unchecked
mData = (List<Map<String, ?>>) results.values;
if (results.count > 0) {
notifyDataSetChanged();
} else {
notifyDataSetInvalidated();
}
}
}
}
其它的XML文件配置和【一】中的一致。
最后，主程序代码如下
/*
主Activity代码
*/
public class ListViewTest extends Activity {
/** Called when the activity is first created. */
private ListView listv;
private String urladdress = "http://www.csdnimg.cn/www/images/csdnindex_logo.gif"; //图片的URL地址
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
listv = (ListView) findViewById(R.id.list); //关联到mian的ListView
ArrayList<Map<String, Object>> arrayl = new ArrayList<Map<String, Object>>();
Bitmap bm = new UrlToBitmap(urladdress).returnBitMap(); //先把URL资源转成Bitmap
for(int count = 0; count<15; count++){
Map<String, Object> map= new HashMap<String, Object>();
map.put(“image”, bm); //放入图片资源
map.put(“Text”, “This is a Listview , No. “+ count + ” !”); //放入计数器
arrayl.add(map);
}
//注意这里是MyAdapter
MyAdapter adapte = new MyAdapter(this,
R.layout.content,
new String[] {“image”, “Text”},
new int[]{R.id.img, R.id.text});
listv.setAdapter(adapter);
}
}
PS : 由于时间紧迫，来不及测试代码，有问题的话可以留言， 谢谢！