TransitionDrawable&StateListDrawable的使用

这个SDK里面的一段代码:
比较适合来做一个简单的动画(比如文字的渐变放大效果等)

Resources res = getResources();
		TransitionDrawable transition = (TransitionDrawable) res
				.getDrawable(R.drawable.expand_collapse);
		ImageView image = (ImageView) findViewById(R.id.toggle_image);
		image.setImageDrawable(transition);
		//当间隔一秒后显示
		transition.startTransition(1000);

这个expand_collapse.xml文件放到Drawable文件夹当中:

<?xml version="1.0" encoding="utf-8"?>
<transition xmlns:android="http://schemas.android.com/apk/res/android">
	    <item android:drawable="@drawable/image_expand" />
		<item android:drawable="@drawable/image_collapse" />
</transition>

当然在测试的时候需要准备2张图片image_expand,image_collapse
http://xueinsz.iteye.com/blog/767585

<?xml version="1.0" encoding="utf-8"?>
<transition xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:drawable="@drawable/first_image" />
  <item android:drawable="@drawable/second_image" />
</transition> 

final ImageView image = (ImageView) findViewById(R.id.image);
final ToggleButton button = (ToggleButton) findViewById(R.id.button);
button.setOnClickListener(new OnClickListener() {
  @Override
  public void onClick(final View v) {
    TransitionDrawable drawable = (TransitionDrawable) image.getDrawable();
    if (button.isChecked()) {
      drawable.startTransition(500);
    } else {
      drawable.reverseTransition(500);
    }
  }
}); 

http://www.vogella.com/tutorials/AndroidDrawables/article.html



根据Button状态(normal,focused,pressed)显示不同背景图片
1. 在res/drawable目录下添加一个xml文件，用来描述Button在不同状态下对应的不同图片。我这里给该xml文件命名为btn_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="@drawable/btn_pressed" /> <!-- pressed -->
     <item android:state_focused="true"
           android:drawable="@drawable/btn_normal" /> <!-- focused -->
     <item android:drawable="@drawable/btn_normal" /> <!-- default -->
 </selector>

2. 在res/layout目录下，对应的layout xml文件中，将Button的android:background属性设置为btn_background即可。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@drawable/btn_background"
    />
</LinearLayout>

也可以代码实现：

Integer[] mButtonState = { R.drawable.defaultbutton,
                R.drawable.focusedpressed, R.drawable.pressed };
Button mButton = (Button) findViewById(R.id.button);
mButton.setBackgroundDrawable(myButton.setbg(mButtonState));

public StateListDrawable setbg(Integer[] mImageIds) {
            StateListDrawable bg = new StateListDrawable();
            Drawable normal = this.getResources().getDrawable(mImageIds[0]);
            Drawable selected = this.getResources().getDrawable(mImageIds[1]);
            Drawable pressed = this.getResources().getDrawable(mImageIds[2]);
            bg.addState(View.PRESSED_ENABLED_STATE_SET, pressed);
            bg.addState(View.ENABLED_FOCUSED_STATE_SET, selected);
            bg.addState(View.ENABLED_STATE_SET, normal);
            bg.addState(View.FOCUSED_STATE_SET, selected);
            bg.addState(View.EMPTY_STATE_SET, normal);
            return bg;
}

Drawable资源：StateListDrawable，PaintDrawable，ShapeDrawable，NinePatchDrawable，BitmapDrawable
http://www.cnblogs.com/xirihanlin/archive/2010/06/14/1758145.html

LayerDrawable层叠样式layer-list
http://gundumw100.iteye.com/admin/blogs/896923

代码实现ColorStateList及StateListDrawable
http://blog.csdn.net/sodino/article/details/6797821