我有三个值，我使用JSON从mysql数据库中提取它们并在ListView中显示它们。我想要的是我想添加一个点击监听器。我有一个名为urlPageNumHolder的全局字符串变量来保存点击的ListView中的ID，因此当单击列表时，我希望调用loadPage()函数来显示ListVew中单击的项ID的Toast 。我试过了，但每当我点击列表中的项目时，它只会在ListView中最后一项的ID。请F1？以下是完整的代码。
MainActivity.java
package com.myapp;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class MainActivity extends Activity {
private ListView lstView;
private ImageAdapter imageAdapter;
public int currentPage = 1;
public int TotalPage = 0;
public Button btnNext;
public Button btnPre;
public String urlPageNumHolder;
public ProgressDialog dialog;
ArrayList<HashMap<String, Object>> MyArrList = new ArrayList<HashMap<String, Object>>();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// ListView and imageAdapter
lstView = (ListView) findViewById(R.id.listView1);
lstView.setClipToPadding(false);
imageAdapter = new ImageAdapter(getApplicationContext());
lstView.setAdapter(imageAdapter);
// Next
btnNext = (Button) findViewById(R.id.btnNext);
// Perform action on click
btnNext.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
currentPage = currentPage + 1;
ShowData();
}
});
// Previous
btnPre = (Button) findViewById(R.id.btnPre);
// Perform action on click
btnPre.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
currentPage = currentPage - 1;
ShowData();
}
});
// Show first load
ShowData();
// OnClick
lstView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
loadPage();
}
});
}
public void ShowData() {
btnNext.setEnabled(false);
btnPre.setEnabled(false);
new LoadContentFromServer().execute();
dialog = ProgressDialog.show(this, "News", "Loading...", true, false);
}
public void loadPage() {
Toast.makeText(this, urlPageNumHolder, Toast.LENGTH_LONG).show();
}
class LoadContentFromServer extends AsyncTask<Object, Integer, Object> {
@Override
protected Object doInBackground(Object... params) {
String url = "http://10.0.2.2/android/Pagination/getAllData.php";
JSONArray data;
try {
data = new JSONArray(getJSONUrl(url));
MyArrList = new ArrayList<HashMap<String, Object>>();
HashMap<String, Object> map;
int displayPerPage = 7; // Per Page
int TotalRows = data.length();
int indexRowStart = ((displayPerPage * currentPage) - displayPerPage);
if (TotalRows <= displayPerPage) {
TotalPage = 1;
} else if ((TotalRows % displayPerPage) == 0) {
TotalPage = (TotalRows / displayPerPage);
} else {
TotalPage = (TotalRows / displayPerPage) + 1;
TotalPage = (int) TotalPage;
}
int indexRowEnd = displayPerPage * currentPage;
if (indexRowEnd > TotalRows) {
indexRowEnd = TotalRows;
}
for (int i = indexRowStart; i < indexRowEnd; i++) {
JSONObject c = data.getJSONObject(i);
map = new HashMap<String, Object>();
map.put("ImageID", (String) c.getString("ImageID"));
map.put("ItemID", (String) c.getString("ItemID"));
// Thumbnail Get ImageBitmap To Object
map.put("ImagePath", (String) c.getString("ImagePath"));
Bitmap newBitmap = loadBitmap(c.getString("ImagePath"));
map.put("ImagePathBitmap", newBitmap);
MyArrList.add(map);
publishProgress(i);
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
public void onProgressUpdate(Integer... progress) {
imageAdapter.notifyDataSetChanged();
}
@Override
protected void onPostExecute(Object result) {
// Disabled Button Next
if (currentPage >= TotalPage) {
btnNext.setEnabled(false);
} else {
btnNext.setEnabled(true);
}
// Disabled Button Previos
if (currentPage <= 1) {
btnPre.setEnabled(false);
} else {
btnPre.setEnabled(true);
}
// dismiss the progress dialog
if(dialog != null) dialog.dismiss();
}
}
class ImageAdapter extends BaseAdapter {
private Context mContext;
public ImageAdapter(Context context) {
mContext = context;
}
public int getCount() {
return MyArrList.size();
}
public Object getItem(int position) {
return MyArrList.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null) {
convertView = inflater.inflate(R.layout.activity_column, null);
}
// ColImagePath
ImageView imageView = (ImageView) convertView.findViewById(R.id.ColImagePath);
imageView.getLayoutParams().height = 100;
imageView.getLayoutParams().width = 100;
imageView.setPadding(5, 5, 5, 5);
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
try {
imageView.setImageBitmap((Bitmap) MyArrList.get(position).get("ImagePathBitmap"));
} catch (Exception e) {
// When Error
imageView.setImageResource(android.R.drawable.ic_menu_report_image);
}
// ColImageID
TextView txtImgID = (TextView) convertView.findViewById(R.id.ColImageID);
txtImgID.setPadding(10, 0, 0, 0);
txtImgID.setText(MyArrList.get(position).get("ImageID").toString());
// ColItemID
TextView txtItemID = (TextView) convertView.findViewById(R.id.ColItemID);
txtItemID.setPadding(10, 0, 0, 0);
txtItemID.setText(MyArrList.get(position).get("ItemID").toString());
//Hold Detail's URL
urlPageNumHolder = MyArrList.get(position).get("ImageID").toString();
return convertView;
}
}
/*** Get JSON Code from URL ***/
public String getJSONUrl(String url) {
StringBuilder str = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
try {
HttpResponse response = client.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) { // Download OK
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(content));
String line;
while ((line = reader.readLine()) != null) {
str.append(line);
}
} else {
Log.e("Log", "Failed to download file..");
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return str.toString();
}
/***** Get Image Resource from URL (Start) *****/
private static final String TAG = "Image";
private static final int IO_BUFFER_SIZE = 4 * 1024;
public static Bitmap loadBitmap(String url) {
Bitmap bitmap = null;
InputStream in = null;
BufferedOutputStream out = null;
try {
in = new BufferedInputStream(new URL(url).openStream(), IO_BUFFER_SIZE);
final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();
out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE);
copy(in, out);
out.flush();
final byte[] data = dataStream.toByteArray();
BitmapFactory.Options options = new BitmapFactory.Options();
// options.inSampleSize = 1;
bitmap = BitmapFactory.decodeByteArray(data, 0, data.length,
options);
} catch (IOException e) {
Log.e(TAG, "Could not load Bitmap from: " + url);
} finally {
closeStream(in);
closeStream(out);
}
return bitmap;
}
private static void closeStream(Closeable stream) {
if (stream != null) {
try {
stream.close();
} catch (IOException e) {
android.util.Log.e(TAG, "Could not close stream", e);
}
}
}
private static void copy(InputStream in, OutputStream out) throws IOException {
byte[] b = new byte[IO_BUFFER_SIZE];
int read;
while ((read = in.read(b)) != -1) {
out.write(b, 0, read);
}
}
/***** Get Image Resource from URL (End) *****/
}
答案 0 :(得分：0)
看起来你在点击时调用了loadPage，你需要传入点击了loadPage方法的索引，然后调用MyArrList.get(position);来获取你点击的位置，然后用它做你想做的任何事情
答案 1 :(得分：0)
urlPageNumHolder仅设置在一行urlPageNumHolder = MyArrList.get(position).get("ImageID").toString()中，与所点击的项目无关。
将public void loadPage() {...}修改为
public void loadPage(long id) {
Toast.makeText(this, String.valueOf(id), Toast.LENGTH_LONG).show();
}
并将其调用为：
listView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
loadPage(id);
}
});
基本上，onItemClickListener会告诉您哪个项目被您最初忽略的id参数点击了。此参数应用于标识已单击的项目。
编辑： id可能不足以为您确定数据。在这种情况下，可以修改loadPage，如下所示。
public void loadPage(long id) {
Toast.makeText(this, MyArrList.get(position).get("ImageID").toString(), Toast.LENGTH_LONG).show();
}
注意：我的代码可能无法正常工作，您可能需要执行一些int到long转换（反之亦然）
答案 2 :(得分：0)
我看到你发现onitemclicklistner很棒，但是按钮列表视图按钮消耗了点击。简单的解决方案是用textview或图标图标替换按钮。另一种解决方案是，你不能使用findviewbyid因为你必须在数组中的每个按钮上创建一个按钮数组和onitemclick侦听器。所以它将以编程方式完成而不是在xml中（无论如何都是按钮） 此外，我不确定您的列表适配器，因此YouTube幻灯片89 custombaseadapterhttp：//m.youtube.com/watch？v = ka5Tk7J9rG0