我想把懒人加载图片放到我的ListView中，图片加载正常，但我有一个问题。加载图像时可以互换。
假设ListView有10行。它加载第一行的图像，它在第一行显示，然后加载第二行的图像。它会在第2行显示片刻，然后显示第1行第2行的图像。然后row1中的ImageView在第1行和第2行的图像之间切换。同样在加载下一行的图像时。前一行的图像之间切换。然后在加载所有图像后，一切都会正确显示。
这是我的代码
Adapater类：
public class FamilyMemberListAdapter extends ArrayAdapter<Map<String, String>> {
List<Map<String, String>> familyMemberList = new ArrayList<Map<String, String>>();
private Activity activity;
public FamilyMemberListAdapter(Activity activity,
List<Map<String, String>> familyMemberList) {
super(activity, R.layout.activity_gch_family_members, familyMemberList);
this.activity = activity;
this.familyMemberList = familyMemberList;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(this.getContext()).inflate(
R.layout.activity_gch_family_member_item, parent, false);
holder = new ViewHolder();
holder.lblFamilyMemberName = (TextView) convertView
.findViewById(R.id.lblFamilyMemberItem);
holder.lblFamilyMemberRelation = (TextView) convertView
.findViewById(R.id.lblFamilyMemberRelationItem);
holder.imgProfilePic = (ImageView) convertView
.findViewById(R.id.imgvProfilePic);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
int accountId = Integer.valueOf(familyMemberList.get(position).get(
"accountId"));
holder.lblFamilyMemberName.setText("Name: "
+ familyMemberList.get(position).get("name"));
holder.lblFamilyMemberRelation.setText("Relation: "
+ familyMemberList.get(position).get("relation"));
if (holder.imgProfilePic != null) {
new ImageDownloaderTask(holder.imgProfilePic).execute(String
.valueOf(accountId));
}
return convertView;
}
@Override
public int getCount() {
return familyMemberList.size();
}
static class ViewHolder {
TextView lblFamilyMemberName;
TextView lblFamilyMemberRelation;
ImageView imgProfilePic;
}
}
Imageloader AsyncTask：
public class ImageDownloaderTask extends AsyncTask<String, Void, Bitmap> {
private final WeakReference<ImageView> imageViewReference;
public ImageDownloaderTask(ImageView imageView) {
imageViewReference = new WeakReference<ImageView>(imageView);
}
@Override
protected Bitmap doInBackground(String... params) {
String responseText = null;
HttpClient httpClient = ServiceHelper.getHttpClient();
HttpContext localContext = new BasicHttpContext();
HttpGet httpGet = new HttpGet(RestApiPaths.GET_PROFILE_PIC + accountId);
try {
HttpResponse response = httpClient.execute(httpGet);
int statusCode = response.getStatusLine().getStatusCode();
final HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream inputStream = null;
try {
// getting contents from the stream
inputStream = entity.getContent();
// decoding stream data back into image Bitmap that android understands
final Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
return bitmap;
} finally {
if (inputStream != null) {
inputStream.close();
}
entity.consumeContent();
}
}
Log.d(TAG, responseText);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Bitmap bitmap) {
if (isCancelled()) {
bitmap = null;
}
if (imageViewReference != null) {
ImageView imageView = imageViewReference.get();
if (imageView != null) {
if (bitmap != null) {
imageView.setImageBitmap(bitmap);
} else {
Drawable placeholder = imageView.getContext().getResources().getDrawable(R.drawable.holder_pic_side);
imageView.setImageDrawable(placeholder);
}
}
}
}
}
我为ListView项创建了一个Static类。仍然为什么图像在加载时继续交换。请告诉我这里我做错了什么。
答案 0 :(得分：1)
在调用AsyncTask之前添加onPostExecute。在您的任务中添加额外的参数accountId。然后在<script type="text/javascript">
$(document).ready(function ()
{
//Test values
var intensity = 5;
var trackerList = ["a", "b", "c", "d", "e"];
var registeredTrackableObjects = ["a", "b", "c", "d"];
var xDistance = 1.05;//Distance between bars
var yMin = 0;
var yMax = 20;
var xMin = 0;
var xMax = 10;
var data = [];//Flot JS format, which contains pairs of {label, array}
var customBarArray = [];
var customBar = [];
//Create a data set for every TO
for(i = 0; i<registeredTrackableObjects.length; i++)
{
//Create 1 bar for every tracker
customBar = [];
for(j = 0; j<trackerList.length; j++)
{
customBar[j] = j;
customBar.push([xDistance * j, intensity]);
}
customBarArray.push(customBar);
var name = "Beacon: " + i;
data.push({label: name, data: customBarArray[i]});
xDistance += 1.05;
}
$.plot($("#placeholder"), data,
{
series: {
bars: {
show: true,
barWidth: 0.1,
lineWidth: 0,
order: 1,
fillColor: {
colors: [{
opacity: 1
}, {
opacity: 0.7
}]
}
}
},
xaxis: {
mode: "time",
min: xMin,
max: xMax,
tickLength: 0,
tickSize: [1, "month"],
axisLabel: 'Month',
axisLabelUseCanvas: true,
axisLabelFontSizePixels: 10,
axisLabelFontFamily: 'Verdana, Arial, Helvetica, Tahoma, sans-serif',
axisLabelPadding: 1
},
yaxis: {
min: yMin,
max: yMax,
axisLabel: 'Value',
axisLabelUseCanvas: true,
axisLabelFontSizePixels: 10,
axisLabelFontFamily: 'Verdana, Arial, Helvetica, Tahoma, sans-serif',
axisLabelPadding: 5
},
legend: {
backgroundColor: "#EEE",
labelBoxBorderColor: "none"
},
colors: ["#AA4643", "#89A54E", "#4572A7"]
});
});
</script>中检查它是否与图像视图中的帐户ID相同
答案 1 :(得分：0)
也许尝试使用像毕加索或通用图像加载器之类的库。 他们用图像加载解决了大部分问题