我想在textview之前想要图像，并希望在每一行中自定义TextView，但我很难实现它，因为已经有xml这样的布局文件 simple_list_item_1 内置。 请帮助我如何实现它。
这是simple_list_item编码
<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (C) 2006 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/text1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="20sp"
android:textStyle="bold"
android:textAppearance="?android:attr/textAppearanceListItemSmall"
android:gravity="center_vertical"
android:paddingStart="?android:attr/listPreferredItemPaddingStart"
android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
android:minHeight="?android:attr/listPreferredItemHeightSmall"
/>
主要活动
public class MainActivity extends ListActivity {
private ListActivity activity;
final static String ScreenName = "google";
final static String LOG_TAG = "rnc";
ListView listview;
TextView text;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.twit_list);
listview = this.getListView();
activity = this;
downloadTweets();
listview.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// selected item
String lst_txt = parent.getItemAtPosition(position).toString().trim();
// Launching new Activity on selecting single List Item
Intent i = new Intent(MainActivity.this, SingleListItem.class);
// sending data to new activity
i.putExtra("product",lst_txt );
startActivity(i);
}
});
}
// download twitter timeline after first checking to see if there is a network connection
public void downloadTweets() {
ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
if (networkInfo != null && networkInfo.isConnected()) {
new DownloadTwitterTask().execute(ScreenName);
} else {
Log.v(LOG_TAG, "No network connection available.");
}
}
// Uses an AsyncTask to download a Twitter user's timeline
private class DownloadTwitterTask extends AsyncTask<String, Void, String> {
final static String CONSUMER_KEY = "keyvaluexxxxx";
final static String CONSUMER_SECRET = "secretkeyxxxxxxx";
final static String TwitterTokenURL = "https://api.twitter.com/oauth2/token";
final static String TwitterStreamURL = "https://api.twitter.com/1.1/statuses/user_timeline.json?screen_name=";
private ProgressDialog progressDialog;
@Override
// can use UI thread here
protected void onPreExecute() {
//this.progressDialog = ProgressDialog.show(Boys.this, ""," Look whose back !! Ok Let me see what i have for you ");
try{
progressDialog = new ProgressDialog(MainActivity.this,AlertDialog.THEME_HOLO_DARK);
progressDialog.setIndeterminate(true);
progressDialog.setIndeterminateDrawable(getResources().getDrawable(R.drawable.loader_2));
progressDialog.setMessage("Please Wait ! Unwrapping Something for You...");
progressDialog.show();
progressDialog.setCancelable(false);
progressDialog.setCanceledOnTouchOutside(false);
}
catch(Exception e)
{
this.progressDialog.dismiss();
Toast.makeText(getApplicationContext(),e.toString(), Toast.LENGTH_LONG).show();
}
}
@Override
protected String doInBackground(String... screenNames) {
String result = null;
if (screenNames.length > 0) {
result = getTwitterStream(screenNames[0]);
}
return result;
}
// onPostExecute convert the JSON results into a Twitter object (which is an Array list of tweets
@Override
protected void onPostExecute(String result) {
Twitter twits = jsonToTwitter(result);
// lets write the results to the console as well
for (Tweet tweet : twits) {
Log.i(LOG_TAG, tweet.getText());
}
// send the tweets to the adapter for rendering
ArrayAdapter<Tweet> adapter = new ArrayAdapter<Tweet>(activity, android.R.layout.simple_list_item_1, twits);
setListAdapter(adapter);
this.progressDialog.dismiss();
}
// converts a string of JSON data into a Twitter object
private Twitter jsonToTwitter(String result) {
Twitter twits = null;
if (result != null && result.length() > 0) {
try {
Gson gson = new Gson();
twits = gson.fromJson(result, Twitter.class);
} catch (IllegalStateException ex) {
// just eat the exception
}
}
return twits;
}
// convert a JSON authentication object into an Authenticated object
private Authenticated jsonToAuthenticated(String rawAuthorization) {
Authenticated auth = null;
if (rawAuthorization != null && rawAuthorization.length() > 0) {
try {
Gson gson = new Gson();
auth = gson.fromJson(rawAuthorization, Authenticated.class);
} catch (IllegalStateException ex) {
// just eat the exception
}
}
return auth;
}
private String getResponseBody(HttpRequestBase request) {
StringBuilder sb = new StringBuilder();
try {
DefaultHttpClient httpClient = new DefaultHttpClient(new BasicHttpParams());
HttpResponse response = httpClient.execute(request);
int statusCode = response.getStatusLine().getStatusCode();
String reason = response.getStatusLine().getReasonPhrase();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
InputStream inputStream = entity.getContent();
BufferedReader bReader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"), 8);
String line = null;
while ((line = bReader.readLine()) != null) {
sb.append(line);
}
} else {
sb.append(reason);
}
} catch (UnsupportedEncodingException ex) {
} catch (ClientProtocolException ex1) {
} catch (IOException ex2) {
}
return sb.toString();
}
private String getTwitterStream(String screenName) {
String results = null;
// Step 1: Encode consumer key and secret
try {
// URL encode the consumer key and secret
String urlApiKey = URLEncoder.encode(CONSUMER_KEY, "UTF-8");
String urlApiSecret = URLEncoder.encode(CONSUMER_SECRET, "UTF-8");
// Concatenate the encoded consumer key, a colon character, and the
// encoded consumer secret
String combined = urlApiKey + ":" + urlApiSecret;
// Base64 encode the string
String base64Encoded = Base64.encodeToString(combined.getBytes(), Base64.NO_WRAP);
// Step 2: Obtain a bearer token
HttpPost httpPost = new HttpPost(TwitterTokenURL);
httpPost.setHeader("Authorization", "Basic " + base64Encoded);
httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");
httpPost.setEntity(new StringEntity("grant_type=client_credentials"));
String rawAuthorization = getResponseBody(httpPost);
Authenticated auth = jsonToAuthenticated(rawAuthorization);
// Applications should verify that the value associated with the
// token_type key of the returned object is bearer
if (auth != null && auth.token_type.equals("bearer")) {
// Step 3: Authenticate API requests with bearer token
HttpGet httpGet = new HttpGet(TwitterStreamURL + screenName);
// construct a normal HTTPS request and include an Authorization
// header with the value of Bearer <>
httpGet.setHeader("Authorization", "Bearer " + auth.access_token);
httpGet.setHeader("Content-Type", "application/json");
// update the results with the body of the response
results = getResponseBody(httpGet);
}
} catch (UnsupportedEncodingException ex) {
} catch (IllegalStateException ex1) {
}
return results;
}
}
}
此处 twit_list.xml 附带 MainActivity.java
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/bis"
>
<ListView
android:id="@android:id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</ListView>
</LinearLayout>
答案 0 :(得分：2)
在布局文件夹
中创建custom_item
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<ImageView
android:id="@+id/listItemImgView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="@string/done"
android:src="@drawable/ic_launcher" />
<TextView
android:id="@+id/listItemTxtView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1" />
</LinearLayout>
像这样创建一个自定义适配器
public class CustomAdapter extends ArrayAdapter<Tweet> {
private Context mContext;
private int layoutId;
private ArrayList<Tweet> dataList;
public CustomAdapter(Context context, int resourceId,
ArrayList<Tweet> objects) {
super(context, resourceId, objects);
// TODO Auto-generated constructor stub
mContext = context;
layoutId = resourceId;
dataList = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
ViewHolder viewHolder;
if(convertView == null) {
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(layoutId, null);
viewHolder = new ViewHolder();
viewHolder.listItemTxtView = (TextView) convertView.findViewById(R.id.listItemTxtView);
viewHolder.listItemImgView = (ImageView) convertView.findViewById(R.id.listItemImgView);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.listItemTxtView.setText(dataList.get(position).toString());
//place picasso jar into libs folder of your project and use it for download and set images like this
Picasso.with(context).load("url of image you want to load").into(viewHolder.listItemImgView);
return convertView;
}
private class ViewHolder {
TextView listItemTxtView;
ImageView listItemImgView;
}
}
download picasso jar from here
而不是
ArrayAdapter<Tweet> adapter = new ArrayAdapter<Tweet>(activity, android.R.layout.simple_list_item_1, twits);
setListAdapter(adapter);
使用此
CustomAdapter adapter = new CustomAdapter(MainActivity.this, R.layout.custom_item, twits);
setListAdapter(adapter);