how to change background image of button when clic

问题:

I want to change the background image of a button when clicked or focused.

This is my code:

Button tiny = (Button)findViewById(R.id.tiny);
tiny.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        Button tiny = (Button)findViewById(R.id.tiny);
        tiny.setBackgroundResource(R.drawable.a9p_09_11_00754);

        TextView txt = (TextView)findViewById(R.id.txt);
        txt.setText("!---- On click ----!");
    }
});

Is this code right? Does it calls a button on its event?

回答1:

you can implement in a xml file for this as follows:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_focused="true" android:drawable="@drawable/your_imagename_while_focused"/>
<item android:state_pressed="true" android:drawable="@drawable/your_imagename_while_pressed" />
<item android:drawable="@drawable/image_name_while_notpressed" />  //means normal
</selector>

now save this xml file in drawable folder and name it suppos abc.xml and set it as follows

 Button tiny = (Button)findViewById(R.id.tiny);
 tiny.setBackgroundResource(R.drawable.abc);

Hope it will help you. :)

回答2:

Its very easy to implement . For that you need to create a one xml file(selector file) and put it in drawable folder in res. After that set xml file in button's background in your layout file.

button_background_selector.xml

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

Now set the above file in button's background.

<Button
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"
    android:textColor="@color/grey_text"
    android:background="@drawable/button_background_selector"/>

回答3:

Sorry this is wrong.

For changing background color/image based on the particular event(focus, press, normal), you need to define a button selector file and implement it as background for button.

For example: button_selector.xml (define this file inside the drawable folder)

<?xml version="1.0" encoding="utf-8"?>
 <selector xmlns:android="http://schemas.android.com/apk/res/android">
     <item android:state_pressed="true"
           android:color="#000000" /> <!-- pressed -->
     <item android:state_focused="true"
           android:color="#000000" /> <!-- focused -->
     <item android:color="#FFFFFF" /> <!-- default -->
 </selector>

    <!-- IF you want image instead of color then write 
android:drawable="@drawable/your_image" inside the <item> tag -->

And apply it as:

 <Button
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:drawable="@drawable/button_selector.xml" />

回答4:

use this code create xml file in drawable folder name:button

<?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/buutton_pressed" />
  <item 
     android:drawable="@drawable/button_image" />
</selector>

and in button xml file

 android:background="@drawable/button"

回答5:

To change the button background we can follow 2 methods

1. In the button OnClick, just add this code:

    public void onClick(View v) {
        if(v == buttonName) {
           buttonName.setBackgroundDrawable
            (getResources().getDrawable(R.drawable.imageName_selected));
         }
   
          }
   

   2.Create button_background.xml in the drawable folder.(using xml)

   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_selected="true"
                  android:drawable="@drawable/tabs_selected" /> <!-- selected-->
            <item android:state_pressed="true"
                  android:drawable="@drawable/tabs_selected" /> <!-- pressed-->
            <item  android:drawable="@drawable/tabs_selected"/>
       </selector>
   

   Now set the above file in button's background file.

        <Button
              android:layout_width="fill_parent" 
              android:layout_height="wrap_content"
              android:background="@drawable/button_background"/>
   
                             (or)
   
            Button tiny = (Button)findViewById(R.id.tiny);
                  tiny.setBackgroundResource(R.drawable.abc);
   

   2nd method is better for setting the background fd button

回答6:

You just need to set background and give previous.xml file in background of button in your layout file.

<Button
 android:id="@+id/button1"
 android:background="@drawable/previous"
 android:layout_width="200dp"
 android:layout_height="126dp"
 android:text="Hello" />

and done.Edit Following is previous.xml file in drawable directory

<?xml version="1.0" encoding="utf-8"?>

<item android:drawable="@drawable/onclick" android:state_selected="true"></item>
<item android:drawable="@drawable/onclick" android:state_pressed="true"></item>
<item android:drawable="@drawable/normal"></item>

回答7:

You can also create shapes directly inside the item tag, in case you want to add some more details to your view, like this:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true">
        <shape>
            <solid android:color="#81ba73" />
            <corners android:radius="6dp" />
        </shape>
        <ripple android:color="#c62828"/>
    </item>
    <item android:state_enabled="false">
        <shape>
            <solid android:color="#788e73" />
            <corners android:radius="6dp" />
        </shape>
    </item>
    <item>
        <shape>
            <solid android:color="#add8a3" />
            <corners android:radius="6dp" />
        </shape>
    </item>
</selector>

Beware that Android will cycle through the items from top to bottom, therefore, you must place the item without condition on the bottom of the list (so it acts like a default/fallback).