page.title=Notepad Extra Credit parent.title=Notepad Tutorial parent.link=index.html @jd:body <p><em>In this exercise, you will use the debugger to look at the work you did in Exercise 3. This exercise demonstrates:</em></p> <ul> <li><em>How to set breakpoints to observe execution</em> </li> <li><em>How to run your application in debug mode</code></em></li> </ul> <div style="float:right;white-space:nowrap"> [<a href="notepad-ex1.html">Exercise 1</a>] [<a href="notepad-ex2.html">Exercise 2</a>] [<a href="notepad-ex3.html">Exercise 3</a>] <span style="color:#BBB;"> [<a href="notepad-extra-credit.html" style="color:#BBB;">Extra Credit</a>] </span> </div> <h2>Step 1</h2> <p>Using the working <code>Notepadv3</code>, put breakpoints in the code at the beginning of the <code>onCreate()</code>, <code>onPause()</code>, <code>onSaveInstanceState()</code> and <code>onResume()</code> methods in the <code>NoteEdit</code> class (if you are not familiar with Eclipse, just right click in the narrow grey border on the left of the edit window at the line you want a breakpoint, and select <em>Toggle Breakpoint</em>, you should see a blue dot appear).</p> <h2>Step 2</h2> <p>Now start the notepad demo in debug mode:</p> <ol type="a"> <li> Right click on the <code>Notepadv3</code> project and from the Debug menu select <em>Debug As -> Android Application.</em></li> <li> The Android emulator should say <em>"waiting for debugger to connect"</em> briefly and then run the application.</li> <li> If it gets stuck on the waiting... screen, quit the emulator and Eclipse, from the command line do an <code>adb kill-server</code>, and then restart Eclipse and try again.</li></ol> <h2>Step 3</h2> <p>When you edit or create a new note you should see the breakpoints getting hit and the execution stopping.</p> <h2>Step 4</h2> <p>Hit the Resume button to let execution continue (yellow rectangle with a green triangle to its right in the Eclipse toolbars near the top).</p> <h2>Step 5</h2> <p>Experiment a bit with the confirm and back buttons, and try pressing Home and making other mode changes. Watch what life-cycle events are generated and when.</p> <p>The Android Eclipse plugin not only offers excellent debugging support for your application development, but also superb profiling support. You can also try using <a href="{@docRoot}guide/developing/tools/traceview.html">Traceview</a> to profile your application. If your application is running too slow, this can help you find the bottlenecks and fix them.</p>