Decrease the brightness of the screen on button click
<p>I have a problem that I want to decrease the brightness of the screen on the button click but failed to do that. I don't know why? I have written the code of few lines but it doesn't work for me. Please suggest me the right solution regarding the same.</p>

<p><strong>Code:</strong></p>

<pre><code>private void setBrightness() {  

        try {
            int curBrightnessValue = android.provider.Settings.System.getInt(getContentResolver(), android.provider.Settings.System.SCREEN_BRIGHTNESS);
            WindowManager.LayoutParams layoutParams = getWindow().getAttributes();
            layoutParams.screenBrightness = curBrightnessValue/100.0f;
            getWindow().setAttributes(layoutParams);
        } catch (SettingNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
      }  
</code></pre>
