Seznam smartphonu podle ceny

Try insert + before R.drawable.xxxx

// error
InputStream is = context.getResources().openRawResource(R.drawable.app_sample_code);

// ok
InputStream is = context.getResources().openRawResource(+R.drawable.app_sample_code);

If you using Context as parameter of function try this solution:

public class MyActivity extends Activity {
// bla bla bla .......
//error 
myFc( getapplicationcontext());
// OK
myFc(MyActivity.this);

android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.my_package/com.example.my_package.MainClass}; have you declared this activity in your AndroidManifest.xml?

Is MainClass.java in AndroidManifest as a activity ?
AndroidManifest.xml example

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="//schemas.android.com/apk/res/android"
      package="com.example.my_packag"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="7" />

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".MainClass"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
</manifest>

Tutorial by pictures how evaluate a variable in Eclipse debugger window.

1.) Open Debug perspective in Eclipse and to start debugging a Activity.



2.) Open Display window from menu Window->Show view->Display



3.) Set breakpoint where you need to evaluate a variable.



4.) Debug the Activity to breakpoint.




5.) Into the Display window type code for evaluate your variable and execute code.




6.) Check if change of value a variable

Dialog Yes No sample code

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("Are you sure you want to exit application?")
       .setCancelable(false)
       .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int id) {
                MyActivity.this.finish(); //Close  this Activity for example: MyActivity.java
           }
       })
       .setNegativeButton("No", new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int id) {
                // some code if you want
                dialog.cancel();
           }
       });
AlertDialog alert = builder.create();
alert.show();