2.3.6 开关按钮ToggleButton和开关Switch

本节引言：

本节给大家介绍的Android基本UI控件是:开关按钮ToggleButton和开关Switch，可能大家对着两个组件 并不熟悉，突然想起笔者的第一间外包公司，是否在wifi下联网的开关，竟然用的TextView，然后叫美工 且两个切换前后的图，然后代码中进行设置，当然点击TextView的时候判断状态，然后设置对应的背景...

好吧，也是醉了，好吧...本节讲解的两个其实都是开关组件，只是后者需要在Android 4.0以后才能使用 所以AndroidManifest.xml文件中的minsdk需要 >= 14 否则会报错~，先来看看这两个控件长什么样先， Android 5.0后这两个控件相比以前来说好看了许多，先看下5.0前的样子：

5.0以前的ToggleButton和Switch： 5.0版本：

好吧，鲜明的对比...接下来我们就来学习者两个控件的使用吧，其实两个的使用几乎是相同的。

开始之前贴下官方API先：Switch；ToggleButton

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1.核心属性讲解：

1）ToggleButton(开关按钮)

可供我们设置的属性：

• android:disabledAlpha：设置按钮在禁用时的透明度
• android:textOff：按钮没有被选中时显示的文字
• android:textOn：按钮被选中时显示的文字 另外，除了这个我们还可以自己写个selector，然后设置下Background属性即可~

2) Switch(开关)

可供我们设置的属性：

• android:showText：设置on/off的时候是否显示文字,boolean
• android:splitTrack：是否设置一个间隙，让滑块与底部图片分隔,boolean
• android:switchMinWidth：设置开关的最小宽度
• android:switchPadding：设置滑块内文字的间隔
• android:switchTextAppearance：设置开关的文字外观，暂时没发现有什么用...
• android:textOff：按钮没有被选中时显示的文字
• android:textOn：按钮被选中时显示的文字
• android:textStyle：文字风格，粗体，斜体写划线那些
• android:track：底部的图片
• android:thumb：滑块的图片
• android:typeface：设置字体，默认支持这三种:sans, serif, monospace;除此以外还可以使用 其他字体文件(*.ttf)，首先要将字体文件保存在assets/fonts/目录下，不过需要在Java代码中设置： Typeface typeFace =Typeface.createFromAsset(getAssets(),"fonts/HandmadeTypewriter.ttf"); textView.setTypeface(typeFace);

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2.使用示例：

因为比较简单，所以我们把他们写到一起，另外，我们为Switch设置下滑块和底部的图片，实现 一个类似于IOS 7的滑块的效果，但是有个缺点就是不能在XML中对滑块和底部的大小进行设置， 就是素材多大，Switch就会多大，我们可以在Java中获得Drawable对象，然后对大小进行修改， 简单的例子：

运行效果图：

实现代码： 先是两个drawable的文件： thumb_selctor.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:drawable="@drawable/switch_btn_pressed"/>
    <item android:state_pressed="false" android:drawable="@drawable/switch_btn_normal"/>
</selector>

track_selctor.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="true" android:drawable="@drawable/switch_btn_bg_green"/>
    <item android:state_checked="false" android:drawable="@drawable/switch_btn_bg_white"/>
</selector>

布局文件:activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">
</span><span class="tag">&lt;ToggleButton</span><span class="pln">
    </span><span class="atn">android:id</span><span class="pun">=</span><span class="atv">"@+id/tbtn_open"</span><span class="pln">
    </span><span class="atn">android:layout_width</span><span class="pun">=</span><span class="atv">"wrap_content"</span><span class="pln">
    </span><span class="atn">android:layout_height</span><span class="pun">=</span><span class="atv">"wrap_content"</span><span class="pln">
    </span><span class="atn">android:checked</span><span class="pun">=</span><span class="atv">"true"</span><span class="pln">
    </span><span class="atn">android:textOff</span><span class="pun">=</span><span class="atv">"关闭声音"</span><span class="pln">
    </span><span class="atn">android:textOn</span><span class="pun">=</span><span class="atv">"打开声音"</span><span class="pln"> </span><span class="tag">/&gt;</span><span class="pln">

</span><span class="tag">&lt;Switch</span><span class="pln">
    </span><span class="atn">android:id</span><span class="pun">=</span><span class="atv">"@+id/swh_status"</span><span class="pln">
    </span><span class="atn">android:layout_width</span><span class="pun">=</span><span class="atv">"wrap_content"</span><span class="pln">
    </span><span class="atn">android:layout_height</span><span class="pun">=</span><span class="atv">"wrap_content"</span><span class="pln">
    </span><span class="atn">android:textOff</span><span class="pun">=</span><span class="atv">""</span><span class="pln">
    </span><span class="atn">android:textOn</span><span class="pun">=</span><span class="atv">""</span><span class="pln">
    </span><span class="atn">android:thumb</span><span class="pun">=</span><span class="atv">"@drawable/thumb_selctor"</span><span class="pln">
    </span><span class="atn">android:track</span><span class="pun">=</span><span class="atv">"@drawable/track_selctor"</span><span class="pln"> </span><span class="tag">/&gt;</span><span class="pln">

</LinearLayout>

MainActivity.java：

public class MainActivity extends AppCompatActivity implements CompoundButton.OnCheckedChangeListener{
</span><span class="kwd">private</span><span class="pln"> </span><span class="typ">ToggleButton</span><span class="pln"> tbtn_open</span><span class="pun">;</span><span class="pln">
</span><span class="kwd">private</span><span class="pln"> </span><span class="typ">Switch</span><span class="pln"> swh_status</span><span class="pun">;</span><span class="pln">

</span><span class="lit">@Override</span><span class="pln">
</span><span class="kwd">protected</span><span class="pln"> </span><span class="kwd">void</span><span class="pln"> onCreate</span><span class="pun">(</span><span class="typ">Bundle</span><span class="pln"> savedInstanceState</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
    </span><span class="kwd">super</span><span class="pun">.</span><span class="pln">onCreate</span><span class="pun">(</span><span class="pln">savedInstanceState</span><span class="pun">);</span><span class="pln">
    setContentView</span><span class="pun">(</span><span class="pln">R</span><span class="pun">.</span><span class="pln">layout</span><span class="pun">.</span><span class="pln">activity_main</span><span class="pun">);</span><span class="pln">

    tbtn_open </span><span class="pun">=</span><span class="pln"> </span><span class="pun">(</span><span class="typ">ToggleButton</span><span class="pun">)</span><span class="pln"> findViewById</span><span class="pun">(</span><span class="pln">R</span><span class="pun">.</span><span class="pln">id</span><span class="pun">.</span><span class="pln">tbtn_open</span><span class="pun">);</span><span class="pln">
    swh_status </span><span class="pun">=</span><span class="pln"> </span><span class="pun">(</span><span class="typ">Switch</span><span class="pun">)</span><span class="pln"> findViewById</span><span class="pun">(</span><span class="pln">R</span><span class="pun">.</span><span class="pln">id</span><span class="pun">.</span><span class="pln">swh_status</span><span class="pun">);</span><span class="pln">
    tbtn_open</span><span class="pun">.</span><span class="pln">setOnCheckedChangeListener</span><span class="pun">(</span><span class="kwd">this</span><span class="pun">);</span><span class="pln">
    swh_status</span><span class="pun">.</span><span class="pln">setOnCheckedChangeListener</span><span class="pun">(</span><span class="kwd">this</span><span class="pun">);</span><span class="pln">
</span><span class="pun">}</span><span class="pln">

</span><span class="lit">@Override</span><span class="pln">
</span><span class="kwd">public</span><span class="pln"> </span><span class="kwd">void</span><span class="pln"> onCheckedChanged</span><span class="pun">(</span><span class="typ">CompoundButton</span><span class="pln"> compoundButton</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">boolean</span><span class="pln"> b</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
    </span><span class="kwd">switch</span><span class="pln"> </span><span class="pun">(</span><span class="pln">compoundButton</span><span class="pun">.</span><span class="pln">getId</span><span class="pun">()){</span><span class="pln">
        </span><span class="kwd">case</span><span class="pln"> R</span><span class="pun">.</span><span class="pln">id</span><span class="pun">.</span><span class="pln">tbtn_open</span><span class="pun">:</span><span class="pln">
            </span><span class="kwd">if</span><span class="pun">(</span><span class="pln">compoundButton</span><span class="pun">.</span><span class="pln">isChecked</span><span class="pun">())</span><span class="pln"> </span><span class="typ">Toast</span><span class="pun">.</span><span class="pln">makeText</span><span class="pun">(</span><span class="kwd">this</span><span class="pun">,</span><span class="str">"打开声音"</span><span class="pun">,</span><span class="typ">Toast</span><span class="pun">.</span><span class="pln">LENGTH_SHORT</span><span class="pun">).</span><span class="pln">show</span><span class="pun">();</span><span class="pln">
            </span><span class="kwd">else</span><span class="pln"> </span><span class="typ">Toast</span><span class="pun">.</span><span class="pln">makeText</span><span class="pun">(</span><span class="kwd">this</span><span class="pun">,</span><span class="str">"打开声音"</span><span class="pun">,</span><span class="typ">Toast</span><span class="pun">.</span><span class="pln">LENGTH_SHORT</span><span class="pun">).</span><span class="pln">show</span><span class="pun">();</span><span class="pln">
            </span><span class="kwd">break</span><span class="pun">;</span><span class="pln">
        </span><span class="kwd">case</span><span class="pln"> R</span><span class="pun">.</span><span class="pln">id</span><span class="pun">.</span><span class="pln">swh_status</span><span class="pun">:</span><span class="pln">
            </span><span class="kwd">if</span><span class="pun">(</span><span class="pln">compoundButton</span><span class="pun">.</span><span class="pln">isChecked</span><span class="pun">())</span><span class="pln"> </span><span class="typ">Toast</span><span class="pun">.</span><span class="pln">makeText</span><span class="pun">(</span><span class="kwd">this</span><span class="pun">,</span><span class="str">"开关:ON"</span><span class="pun">,</span><span class="typ">Toast</span><span class="pun">.</span><span class="pln">LENGTH_SHORT</span><span class="pun">).</span><span class="pln">show</span><span class="pun">();</span><span class="pln">
            </span><span class="kwd">else</span><span class="pln"> </span><span class="typ">Toast</span><span class="pun">.</span><span class="pln">makeText</span><span class="pun">(</span><span class="kwd">this</span><span class="pun">,</span><span class="str">"开关:OFF"</span><span class="pun">,</span><span class="typ">Toast</span><span class="pun">.</span><span class="pln">LENGTH_SHORT</span><span class="pun">).</span><span class="pln">show</span><span class="pun">();</span><span class="pln">
            </span><span class="kwd">break</span><span class="pun">;</span><span class="pln">

    </span><span class="pun">}</span><span class="pln">
</span><span class="pun">}</span><span class="pln">

}

← 2.3.5.RadioButton(单选按钮)&Checkbox(复选框)cs