我一直在使用#!/bin/bash
# Second subshell will get the PID of the first one through the pipe.
# It will be able to kill the whole script by killing the first subshell.
# Create a temporary named pipe (it's safe, conflicts will throw an error).
pipe=$(mktemp -u)
if ! mkfifo $pipe; then
echo "ERROR: debug tracing pipe creation failed." >&2
exit 1
fi
# Attach it to file descriptor 3.
exec 3<>$pipe
# Unlink the named pipe.
rm $pipe
(echo $BASHPID >&3; tee /dev/stderr) | (./script.sh; r=$?; kill $(head -n1 <&3); exit $r) | tee /dev/stderr
exit ${PIPESTATUS[1]}
使用返回图片的网址填充Picasso。这些URL是从API调用返回的。
适配器
listview我已经做了很多关于此的阅读，并且我尝试使用public class RecipeAdapter extends BaseAdapter implements ListAdapter {
private final Activity activity;
private final JSONArray jsonArray;
public RecipeAdapter (Activity activity, JSONArray jsonArray){
assert activity !=null;
assert jsonArray != null;
this.jsonArray = jsonArray;
this.activity = activity;
}
@Override
public int getCount(){
if(null==jsonArray)
return 0;
else
return jsonArray.length();
}
@Override
public JSONObject getItem(int position){
if(null==jsonArray) return null;
else
return jsonArray.optJSONObject(position);
}
@Override
public long getItemId(int position){
return position;
}
@Override
public View getView (int position, View v, ViewGroup parent){
if (v == null) {
v = View.inflate(activity, R.layout.recipe_item, null);
}
CircularImageView icon = (CircularImageView)v.findViewById(R.id.recipeIcon);
TextView title = (TextView) v.findViewById(R.id.recipeTitle);
TextView supplier = (TextView) v.findViewById(R.id.supplier);
JSONObject JSdata = getItem(position);
if(null!=JSdata){
try {
if (JSdata.has("title")) {
title.setText(JSdata.getString("title"));
}
if (JSdata.has("publisher")) {
supplier.setText(JSdata.getString("publisher"));
}
if (JSdata.has("image_url")) {
String image = JSdata.getString("image_url");
String[] imagearray = image.split("\\.");
String extension = imagearray[imagearray.length - 1];
String tag = new String();
if (extension.equals("jpg")) {
if (URLUtil.isValidUrl(image)) {
Picasso.with(activity)
.load(image)
.centerCrop()
.tag(tag)
.error(R.drawable.icon01)
.resize(50, 50)
.into(icon);
} else {
Picasso.with(activity)
.load(R.drawable.icon01)
.centerCrop()
.resize(50, 50)
.tag(tag)
.into(icon);
}
}
}
} catch (JSONException e) {
Toast.makeText(activity, "Error finding recipes",
Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
final ImageView fav = (ImageView)v.findViewById(R.id.favbutton);
fav.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
fav.setImageResource(R.drawable.ic_favorite_white_24dp);
Toast.makeText(activity, "Added to favourites",
Toast.LENGTH_SHORT).show();
}
});
return v;
}
}
方法和滚动侦听器：
.tag()我虽然这可能会解决问题，但是当我滚动大型列表时，它会导致应用程序崩溃。 logcat的：
class Populate extends AsyncTask<String, String, JSONArray> {
protected void onPreExecute() {
progress = ProgressDialog.show(RecipeSearch.this, "Finding Recipes", "Searching....", true);
}
@Override
protected JSONArray doInBackground(String... urls) {
JSONParser recipeParse = new JSONParser();
String rawJSON = recipeParse.getJSON(urls[0]);
try {
if (rawJSON != null) {
JSONObject object = new JSONObject(rawJSON);
JSONArray jArray = object.getJSONArray("recipes");
return jArray;
} else {
JSONArray jArray = null;
return jArray;
}
} catch(Exception e) {
System.out.println(e);
Toast.makeText(getApplicationContext(), "Error Searching for Recipes",
Toast.LENGTH_SHORT).show();
JSONArray jArray = null;
return jArray;
}
//do http request and add objects to array here.
//need to do a custom adapter
// return null;
}
@Override
protected void onPostExecute(JSONArray jArray) {
if (jArray != null) {
final ListView recipes = (ListView) findViewById(R.id.recipeView);
recipes.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
JSONObject selected = (JSONObject) (recipes.getItemAtPosition(position));
String url = null;
try {
url = selected.getString("source_url");
} catch (JSONException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Error", Toast.LENGTH_SHORT).show();
}
Intent i = new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);
}
});
final String tag ="";
recipes.setOnScrollListener(new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
Picasso picasso = Picasso.with(getApplicationContext());
if (scrollState == SCROLL_STATE_IDLE ||
scrollState == SCROLL_STATE_TOUCH_SCROLL) {
picasso.resumeTag(tag);
} else {
picasso.pauseTag(tag);
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
Picasso picasso = Picasso.with(getApplicationContext());
picasso.pauseTag(tag);
}
});
recipeAdapter = new RecipeAdapter(RecipeSearch.this, jArray);//jArray is your json array
recipes.setAdapter(recipeAdapter);
} else {
Toast.makeText(getApplicationContext(), "No Recipes Found", Toast.LENGTH_SHORT).show();
finish();
}
progress.dismiss();
}
}
欢迎任何帮助或建议
答案 0 :(得分：0)
我对CircularImageView，图片网址和毕加索有同样的问题。该
问题在于CircularImageView正在加载占位符图像然后是您请求的占位符图像。我在Picasso查询中使用noPlaceholder()解决了这个问题。
您应该可以通过添加noPlaceholder()来修复上述代码
if (URLUtil.isValidUrl(image)) {
Picasso.with(activity)
.load(image)
.centerCrop()
.tag(tag)
.error(R.drawable.icon01)
.resize(50, 50)
.noPlaceholder()
.into(icon);
} else {
Picasso.with(activity)
.load(R.drawable.icon01)
.centerCrop()
.resize(50, 50)
.tag(tag)
.noPlaceholder()
.into(icon);
}
Picasso Github https://github.com/square/picasso/issues/931
详细说明了这个问题