<h3 dir="auto">Preflight Checklist</h3>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have read the <a href="https://github.com/electron/electron/blob/master/CONTRIBUTING.md">Contributing Guidelines</a> for this project.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I agree to follow the <a href="https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md">Code of Conduct</a> that this project adheres to.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have searched the issue tracker for an issue that matches the one I want to file, without success.</li>
</ul>
<h3 dir="auto">Issue Details</h3>
<ul dir="auto">
<li><strong>Electron Version:</strong>
<ul dir="auto">
<li>

</li>
</ul>
</li>
</ul>
<p dir="auto">6.9.0</p>
<ul dir="auto">
<li><strong>Operating System:</strong><br>
Windows 10
<ul dir="auto">
<li>

</li>
</ul>
</li>
<li><strong>Last Known Working Electron version:</strong>
<ul dir="auto">
<li>

</li>
</ul>
</li>
</ul>
<h3 dir="auto">Expected Behavior</h3>

<p dir="auto">The defaultId property in the Options object in dialog.showMessageBox should change the default button.</p>
<h3 dir="auto">Actual Behavior</h3>

<p dir="auto">The defaultId property in the Options object in dialog.showMessageBox isn't changing the default button. The rest of the properties work just fine</p>
<h3 dir="auto">To Reproduce</h3>
<p dir="auto"><code class="notranslate">                    dialog.showMessageBox(mainWindow, { type: 'warning', buttons: ['Yes', 'No', 'Cancel'], defaultId: 2, cancelId: 2, detail: "...you want to continue?", message:"You are about to delete the current calendar!" })</code></p>




<h3 dir="auto">Screenshots</h3>

<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/30180567/83594887-616f8a80-a52e-11ea-8ef4-292a6efe6628.PNG"><img width="418" alt="Capture" src="https://user-images.githubusercontent.com/30180567/83594887-616f8a80-a52e-11ea-8ef4-292a6efe6628.PNG" style="max-width: 100%;"></a></p>
<h3 dir="auto">Additional Information</h3>
<h3 dir="auto">Preflight Checklist</h3>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have read the <a href="https://github.com/electron/electron/blob/master/CONTRIBUTING.md">Contributing Guidelines</a> for this project.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I agree to follow the <a href="https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md">Code of Conduct</a> that this project adheres to.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have searched the issue tracker for an issue that matches the one I want to file, without success.</li>
</ul>
<h3 dir="auto">Issue Details</h3>
<ul dir="auto">
<li><strong>Electron Version:</strong>
<ul dir="auto">
<li>8.0.0</li>
</ul>
</li>
</ul>

<ul dir="auto">
<li><strong>Operating System:</strong>
<ul dir="auto">
<li>Windows 10 (18362)</li>
<li>Ubuntu 14.04 x64</li>
</ul>
</li>
</ul>

<ul dir="auto">
<li><strong>Last Known Working Electron version:</strong>
<ul dir="auto">
<li>

</li>
</ul>
</li>
</ul>
<h3 dir="auto">Expected Behavior</h3>

<p dir="auto"><code class="notranslate">dialog.showMessageBoxSync(null, { type:'warning', buttons: ['Yes', 'No'], defaultId: 1, cancelId: 1, title: 'Power Control', message: "Warning!", });</code><br>
I set "defaultId:1", after executing the function,it should focus on the "No" button.</p>
<h3 dir="auto">Actual Behavior</h3>

<p dir="auto">Execute the function, in windows 10, it focuses on the "Yes" button. And it focuses on the "No" button in Ubuntu 14.04.</p>
<h3 dir="auto">To Reproduce</h3>
<div class="highlight highlight-source-shell notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="$ git clone git@github.com:ForJason/electron-smt.git
$ cd electron-smt
$ npm start"><pre class="notranslate">$ git clone git@github.com:ForJason/electron-smt.git
$ <span class="pl-c1">cd</span> electron-smt
$ npm start</pre></div>




<h3 dir="auto">Screenshots</h3>

<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/25317078/76181106-fd714a80-61fa-11ea-89fb-511014ce84ab.png"><img src="https://user-images.githubusercontent.com/25317078/76181106-fd714a80-61fa-11ea-89fb-511014ce84ab.png" alt="win10" style="max-width: 100%;"></a><br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/25317078/76181111-05c98580-61fb-11ea-9440-475401e0e97d.png"><img src="https://user-images.githubusercontent.com/25317078/76181111-05c98580-61fb-11ea-9440-475401e0e97d.png" alt="ubuntu" style="max-width: 100%;"></a></p>
<h3 dir="auto">Additional Information</h3>