如何在Android中获取列表视图的特定项目的ID? [英] How to get id of particular item of listview in android?
本文介绍了如何在Android中获取列表视图的特定项目的ID?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在使用Listview并设置多个项目，每个项目都有喜欢"，共享"和评论"选项.
实际上，我已经成功获取了项目ID和TextView的setText.但是无法在特定项目的赞按钮单击"事件上获得项目ID.
如何获取Button单击事件上Listview中每个项目的项目ID?
I am using Listview and set the multiple item and each item have Like, share and comment option.
Actually I have fetch the Item Id and also setText of TextView, Its Successfully. But Not able to get Item Id on Like Button Click event for particular item.
How to fetch Item Id for every items in Listview on Button Click Event?
MyAdapter类的演示:
Demo for MyAdapter Class:
public class Adapter1 extends BaseAdapter implements OnClickListener {
public ArrayList<HashMap<String, String>> arr = null;
Context context = null;
LayoutInflater layoutInflater = null;
HashMap<String, String> getData = new HashMap<String, String>();
String urlLike = null;
TextView strId = null;
public NewsFeedAdapter(Context context,
ArrayList<HashMap<String, String>> arr) {
this.context = context;
this.arr= arr;
layoutInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return arr.size();
}
@Override
public Object getItem(int position) {
return arr.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder = null;
if (convertView == null) {
convertView = layoutInflater.inflate(
R.layout.my_list_item, null);
/** initialize ViewHolder */
viewHolder = new ViewHolder();
/** Initialize Widgets */
/** Imageview */
viewHolder.imgLike = (ImageView) convertView
.findViewById(R.id.imgLike);
viewHolder.imgLike.setOnClickListener(this);
viewHolder.imgComments = (ImageView) convertView
.findViewById(R.id.imgComments);
viewHolder.imgComments.setOnClickListener(this);
viewHolder.imgShare = (ImageView) convertView
.findViewById(R.id.imgShare);
viewHolder.imgShare.setOnClickListener(this);
/** TextView */
viewHolder.txtId = (TextView) convertView
.findViewById(R.id.txtId);
viewHolder.txtDescription = (TextView) convertView
.findViewById(R.id.txtDescription);
getData = arr.get(position);
viewHolder.txtId.setText(getData
.get(Fragment1.TAG_ID));
viewHolder.txtDescription.setText(getData
.get(Fragment1.TAG_MESSAGE));
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
convertView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
}
});
return convertView;
}
/** ViewHolder Class */
public class ViewHolder {
ImageView imgLike = null, imgComments = null,
imgShare = null;
TextView txtId = null,txtDescription = null;
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.imgLike:
strId = ((TextView) view
.findViewById(R.id.txtId));
System.out.println("On Click====="
+ strId.getText().toString());
urlLike = "http://www.example.com?id="
+ strId.getText().toString() + "&user_id="
+ myDetail.getUserId();
new sendLikeData().execute();
break;
case R.id.imgComments:
break;
case R.id.imgShare:
break;
default:
break;
}
}
public class sendLikeData extends AsyncTask<Void, Void, Void> {
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... arg0) {
ServiceHandler sh = new ServiceHandler();
String jsonStr = sh.makeServiceCall(urlLike, ServiceHandler.GET);
Log.d("Response : Like", ">" + jsonStr);
return null;
}
protected void onPostExecute(Void result) {
super.onPostExecute(result);
};
}
}
OutPut is, NullPointer Exception in System.out.println("On Click====="
+ strId.getText().toString());.
xml文件是
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/masterLayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="@dimen/five_dp" >
<TextView
android:id="@+id/txtDescription"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_marginLeft="@dimen/ten_dp"
android:layout_marginRight="@dimen/ten_dp"
android:layout_marginTop="@dimen/ten_dp" />
<ImageView
android:id="@+id/imgImage"
android:layout_width="fill_parent"
android:layout_height="150dp"
android:layout_below="@+id/txtDescription"
android:layout_centerHorizontal="true"
android:layout_marginBottom="@dimen/ten_dp"
android:layout_marginLeft="@dimen/ten_dp"
android:layout_marginRight="@dimen/ten_dp"
android:layout_marginTop="@dimen/ten_dp"
android:background="@null"
android:contentDescription="@string/content_description"
android:src="@drawable/ic_launcher" />
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/imgImage"
android:background="@drawable/strip"
android:baselineAligned="false"
android:gravity="center_vertical"
android:orientation="horizontal" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1" >
<ImageView
android:id="@+id/imgLike"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerInParent="true"
android:contentDescription="@string/content_description"
android:src="@drawable/like" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/imgLike"
android:layout_toRightOf="@+id/imgLike"
android:background="@drawable/getbg"
android:gravity="center"
android:padding="@dimen/two_dp"
android:textColor="@color/white"
android:textSize="@dimen/ten_sp" />
</RelativeLayout>
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1" >
<ImageView
android:id="@+id/imgComments"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerInParent="true"
android:contentDescription="@string/content_description"
android:src="@drawable/comments" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@+id/imgComments"
android:background="@drawable/getbg"
android:gravity="center"
android:padding="@dimen/two_dp"
android:text="+1"
android:textColor="@android:color/white"
android:textSize="@dimen/ten_sp" />
</RelativeLayout>
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_weight="1" >
<ImageView
android:id="@+id/imgShare"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerInParent="true"
android:contentDescription="@string/content_description"
android:src="@drawable/share" />
</RelativeLayout>
</LinearLayout>
<TextView
android:id="@+id/txtId"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_margin="@dimen/ten_dp"
android:text="id"
android:textSize="20dp" />
</RelativeLayout>
Logcat是
11-24 18:54:20.354: E/AndroidRuntime(7120): java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.TextView
11-24 18:54:20.354: E/AndroidRuntime(7120): Adapter.onClick(Fragment.java:342)
11-24 18:54:20.354: E/AndroidRuntime(7120): at android.view.View.performClick(View.java:4562)
11-24 18:54:20.354: E/AndroidRuntime(7120): at android.view.View$PerformClick.run(View.java:18918)
11-24 18:54:20.354: E/AndroidRuntime(7120): at android.os.Handler.handleCallback(Handler.java:808)
11-24 18:54:20.354: E/AndroidRuntime(7120): at android.os.Handler.dispatchMessage(Handler.java:103)
11-24 18:54:20.354: E/AndroidRuntime(7120): at android.os.Looper.loop(Looper.java:193)
11-24 18:54:20.354: E/AndroidRuntime(7120): at android.app.ActivityThread.main(ActivityThread.java:5388)
11-24 18:54:20.354: E/AndroidRuntime(7120): at java.lang.reflect.Method.invokeNative(Native Method)
11-24 18:54:20.354: E/AndroidRuntime(7120): at java.lang.reflect.Method.invoke(Method.java:515)
11-24 18:54:20.354: E/AndroidRuntime(7120): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
11-24 18:54:20.354: E/AndroidRuntime(7120): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:655)
11-24 18:54:20.354: E/AndroidRuntime(7120): at dalvik.system.NativeStart.main(Native Method)
推荐答案
尝试以下代码:
public class Adapter1 extends BaseAdapter implements OnClickListener {
public ArrayList<HashMap<String, String>> arr = null;
Context context = null;
LayoutInflater layoutInflater = null;
HashMap<String, String> getData = new HashMap<String, String>();
String urlLike = null;
TextView strId = null;
public NewsFeedAdapter(Context context,
ArrayList<HashMap<String, String>> arr) {
this.context = context;
this.arr= arr;
layoutInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return arr.size();
}
@Override
public Object getItem(int position) {
return arr.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder = null;
if (convertView == null) {
convertView = layoutInflater.inflate(
R.layout.my_list_item, null);
/** initialize ViewHolder */
viewHolder = new ViewHolder();
/** Initialize Widgets */
/** Imageview */
viewHolder.imgLike = (ImageView) convertView
.findViewById(R.id.imgLike);
viewHolder.imgComments = (ImageView) convertView
.findViewById(R.id.imgComments);
viewHolder.imgComments.setOnClickListener(this);
viewHolder.imgShare = (ImageView) convertView
.findViewById(R.id.imgShare);
viewHolder.imgShare.setOnClickListener(this);
/** TextView */
viewHolder.txtId = (TextView) convertView
.findViewById(R.id.txtId);
viewHolder.txtDescription = (TextView) convertView
.findViewById(R.id.txtDescription);
getData = arr.get(position);
viewHolder.txtId.setText(getData
.get(Fragment1.TAG_ID));
viewHolder.txtDescription.setText(getData
.get(Fragment1.TAG_MESSAGE));
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
convertView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
}
});
viewHolder.imgLike.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
strId=arr.get(position).getId();//or whatever you want to do do here.
}
});
return convertView;
}
/** ViewHolder Class */
public class ViewHolder {
ImageView imgLike = null, imgComments = null,
imgShare = null;
TextView txtId = null,txtDescription = null;
}
}
这篇关于如何在Android中获取列表视图的特定项目的ID?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
