Errors

We normally face errors while development of application. Some are common mistakes which we frequently make. Here we list down the error faced while development of Application with reason and resolution adopted in removing the errors


Error Unable to open class file R.java. or R.id. text01 is marked as red even after compilation.
Possible Reason
  1. XML Layout file have errors which need to be removed.
  2. XML file is not getting compiled.
  3. Layout file have
Resolution.     Clean the Project . Select Project → Clean.



Error Null Pointer Error
Possible Reason
    1. The variable or Object that we are creating is not initialized.
    Example:
    public class CartActivity extends Activity {
    TextView lblusername;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_cart);
    // lblusername = (TextView) findViewById(R.id.usernamelbl);
    lblusername.setVisibility(View.GONE);
    As per the example above following may be the reason.
     
  1. lblusername is not not initialized as it is commented or the statement is not defined.
  2. R.id.usernamelbl is not defined within R.layout.activity_cart in XML Layout File.
Resolution. Uncomment // lblusername = (TextView) findViewById(R.id.usernamelbl);
Or lblusername = (TextView) findViewById(R.id.usernamelbl); statement is missing and should be added.


Error ActivityNotFoundException error.
Possible Reason Due to some reason an entry in Android manifest is missing.
Resolution. Add and entry in Android Manifest file as mentioned below.
<activity
android:name=".ComplaintActivity"
android:label="@string/title_activity_complaint" >
</activity>



Error OutofMemoryError error.
Possible Reason This error may occur mainly due to using bit map, gallery , etc. When a request for memory is made that can not be satisfied using the available platform resources.
Resolution.
  1. Try to use Try - Catch block.
  2. Reduce Image size and define as below 
Bitmap bitmap;
bitmap.compress(Bitmap.CompressFormat.PNG,100,outstream);


Error Toast is written properly but nothing is displayed
Possible Reason Show() method is missing.
Resolution. Add the .show() method to show the Toast and see if it is working well.
 
Error Permission Errors.
Possible Reason to AndroidManifest file. Especially while using Internet services,email, google map, read write to SD Card or SMS service.
Resolution. 
<manifest xlmns:android...>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name= 
"android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name= 
"android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" />
<uses-permission android:name=
"android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name=
"com.example.towntour.permission.MAPS_RECEIVE" />
<uses-permission android:name=
"android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name=
"android.permission.CALL_PHONE" />
<uses-permission android:name=
"android.permission.READ_PHONE_STATE" />
<uses-permission android:name=
"com.google.android.providers.gsf.permission.READ_GSERVICES" />
</manifest>


Error appcompat-v7:21.0.0': No resource found that matches the given name: attr 'android:actionModeShareDrawable'
Possible Reason When using the  v7-appcompat in Eclipse we have to use it as a library project. It isn't enough to just copy the *.jar to your /libs folder

As soon as the project is imported,  some folders in the /res folder are red-underlined/crossed.
Resolution. Follow the following steps.
1. Open the project.properties file of the android-support-v7-appcompat and change the target from target=android-19 to target=android-21.
2. Project –> Clean and see the changes take effect.










Subscribe to: Posts (Atom)