CODEWITHSUNDEEP
androidandroid-layoutandroid-listview
Deep Jain
Deep Jain

Reputation: 47

crashing on listview click (listview in relative layout)

this program makes a listview in relativelayout, Listview is coming fine, but when i click on a item it crashes (where a toast is expected) In debug mode, the code crashes on the bold line (i.e. RelativeLayout relativeLayoutChild = (RelativeLayout ) relativeLayoutParent.getChildAt(1);)

public class MainActivity extends Activity {

    ListView mListView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);    

        // URL to the JSON data         
        String strUrl = "http://10.0.2.2/android_conect/conn.php";

        // Creating a new non-ui thread task to download json data 
        DownloadTask downloadTask = new DownloadTask();

        // Starting the download process
        downloadTask.execute(strUrl);

        // Getting a reference to ListView of activity_main
        mListView = (ListView) findViewById(R.id.lv_coordinates);

     // Item Click Listener for the listview
        OnItemClickListener itemClickListener = new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View container, int position, long id) {
                // Getting the Container Layout of the ListView
                RelativeLayout relativeLayoutParent = (RelativeLayout) container;

                // Getting the inner Linear Layout
                **RelativeLayout relativeLayoutChild = (RelativeLayout ) relativeLayoutParent.getChildAt(1);**

                // Getting the Country TextView
                TextView tvId = (TextView) relativeLayoutChild.getChildAt(0);

                Toast.makeText(getBaseContext(), tvId.getText().toString(), Toast.LENGTH_SHORT).show();
            }
        };

        // Setting the item click listener for the listview
        mListView.setOnItemClickListener(itemClickListener);
    }

the layout files are: activity_main.xml

<RelativeLayout 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" >    


    <ListView
        android:id="@+id/lv_coordinates"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        tools:context=".MainActivity" />

</RelativeLayout>

lv_layout.xml

<?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
         android:layout_width="match_parent"
         android:layout_height="match_parent" >

    <TextView 
        android:id="@+id/tv_id"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"        
        android:textStyle="bold" />


    <TextView 
        android:id="@+id/tv_coordinate_details"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/tv_id"  />

</RelativeLayout>

the error message is:

FATAL EXCEPTION: main
 java.lang.ClassCastException: 
android.widget.TextView cannot be cast to android.widget.RelativeLayout
    at com.example.mylistview.MainActivity$1.onItemClick(MainActivity.java:58)
    at android.widget.AdapterView.performItemClick(AdapterView.java:298)
    at android.widget.AbsListView.performItemClick(AbsListView.java:1100)
    at android.widget.AbsListView$PerformClick.run(AbsListView.java:2749)
    at android.widget.AbsListView$1.run(AbsListView.java:3423)
    at android.os.Handler.handleCallback(Handler.java:725)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:137)
    at android.app.ActivityThread.main(ActivityThread.java:5041)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:511)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
    at dalvik.system.NativeStart.main(Native Method)
Sending signal. PID: 2591 SIG: 9

Upvotes: 0

Views: 1041

Answers (3)

blackcj
blackcj

Reputation: 3661

The View container is your lv_layout.xml. relativeLayoutChild is unnecessary, the children of relativeLayoutParent would be your TextViews. You are trying to cast tv_coordinate_details to a RelativeLayout.

Upvotes: 0

mdDroid
mdDroid

Reputation: 3195

Change the following line

 **RelativeLayout relativeLayoutChild = (RelativeLayout ) relativeLayoutParent.getChildAt(1);**

to 

 **TextView tv_coordinate_details= (TextView ) relativeLayoutParent.getChildAt(1);**
   TextView tvId = (TextView) relativeLayoutParent.getChildAt(0);

Upvotes: 1

Simon Dorociak
Simon Dorociak

Reputation: 33495

I think you should get your child widget from layout (row you selected) in this way:

TextView tvId = (TextView) container.findViewById(R.id.tv_id);

Second parameter in onItemClick() method represents rowView (in your case lv_layout.xml). Each row has own lv_layout.xml layout.

So you have direct access to each child widget of each row via this method (it automatic returns whole rowView at clicked position).

Upvotes: 3

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