Apply Different Style to Button When Pressed

Is there a way to apply a s开发者_如何学Gotyle to a button when the button is pressed?

If I have a style in style.xml:

<resources>
    <style name="test">
        <item name="android:textStyle">bold</item>
    </style>
</resources>

a selector in button.xml:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/test_pressed"
              style="@style/test"
          android:state_pressed="true"/>
    <item android:drawable="@drawable/test_focused"
          android:state_focused="true"/>
    <item android:drawable="@drawable/test_normal"/>
</selector>

then how would I reference button.xml in my layout?

<Button
        ...
        android:???="button"/>

Thanks!

Romain Guy suggests it is not possible:

http://code.google.com/p/android/issues/detail?id=8941

"Selector works only for drawables, not text appearances. There is currently not plan to make this happen."

You can achieve this by using an XML button definition.

Create an XML file in your drawable folder as follows:

<?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/green_button" /> 

        <!-- <item android:state_focused="true"
        android:drawable="@drawable/button_focused" /> --> 

        <item android:drawable="@drawable/black_button" />
</selector>

As you can see this allows you to define different button images to use for the different states (black_button, green_button etc should be .PNG files in your drawable folder also)

Now, from your layout.xml file you can just set the button background to point to the button selector:

<Button android:text="Play" android:id="@+id/playBtn"
            android:background="@drawable/button_selector"
            android:textColor="#ffffff" />

The Selector XML can then be referenced from teh drawable folder like any image file can.

You can make use of Color State List Resource

Example from link:

XML file saved at res/color/button_text.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true"
          android:color="#ffff0000"/> <!-- pressed -->
    <item android:state_focused="true"
          android:color="#ff0000ff"/> <!-- focused -->
    <item android:color="#ff000000"/> <!-- default -->
</selector>

This layout XML will apply the color list to a View:

<Button
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/button_text"
    android:textColor="@color/button_text" />

To Change Android Button on Click/Press Color :

Define Color Value

To define color value, you have to create colors.xml file in your project values directory and add following. res/values/colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="button_pressed">#ff8a00</color>
    <color name="button_focused">#ff8a00</color>
    <color name="button_default">#1c76bb</color>
</resources>

Create a XML File in Drawable Directory

Create a button_background.xml file in your drawable folder and add button pressed/clicked, focused and default color. Final code of button_background.xml file looks like this. res/drawable/button_background.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="@color/button_pressed"/> <!-- pressed -->
    <item android:state_focused="true"
        android:drawable="@color/button_focused"/> <!-- focused -->
    <item android:drawable="@color/button_default"/> <!-- default -->
</selector>

Adding Buttons

res/activity_main.xml

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/button_background"
        android:text="Click Me"
        android:textColor="#fff" />

    <Button
        android:id="@+id/button2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/button1"
        android:layout_marginTop="16dp"
        android:background="@drawable/button_background"
        android:text="Click Me"
        android:textColor="#fff" />

</RelativeLayout>

Source here.

<Button
        android:background="@drawable/button"/>

To refer to the selector, you must give it as the background for that Button.

<Button
     android:background="@drawable/button"
/> 

And for Bold when pressed, I haven't tried it either, but maybe you can mention text style in your selector, i.s.o referring to a style from it:

android:textStyle="bold"

If this also does not work, you can do it in button's onClick().

I've not tried it but presumably you could just include android:id="button" in your selector.