android学习之Animation（二）---在xml文件中实现Animation

在xml中实现animation
    一、在res文件夹下新建一个名为anim的文件夹
    二、创建xml文件，首先加入set标签
                     xmlns:android=""
            android:interpolator="@android:anim/accelerate_interpolator"
        >
        
    三、在set标签中加入rotate、translate、alpha、scale标签，每一个动画效果占一个xml文件

    (1)alpha.xml:
         <?xml version="1.0" encoding="utf-8"?>
        <set
         xmlns:android=""
         android:interpolator="@android:anim/accelerate_interpolator">
         <alpha                           <?透明效果?>
         android:fromAlpha="0.1"          <?开始透明度10%?>
         android:toAlpha="1.0"            <?结束透明度?>
         android:duration="3000"          <?设置动画执行时间?>
         android:startOffset="500"        <?设置动画执行前的等待时间?>
         />
        </set>

    (2)rotate.xml:
        <?xml version="1.0" encoding="utf-8"?>
        <set
         xmlns:android=""
         android:interpolator="@android:anim/accelerate_interpolator">
             <rotate                       <?旋转效果?>
             android:fromDegrees="0"       <?起始角度?>
             android:toDegrees="+350"      <?结束角度?>
             android:pivotX="50%"          <?旋转点的x坐标 “50”代表绝对位置，“50%”相对于控件本身，“50%p”相对于父控件?>
             android:pivotY="50%"          <?旋转点的y坐标?>
             android:duration="3000"       <?动画执行的时间?>
         />
        </set>
    (3)scale.xml
        <?xml version="1.0" encoding="utf-8"?>
        <set
         xmlns:android=""
         android:interpolator="@android:anim/accelerate_interpolator">
            <scale                              <?缩放效果?>
                android:fromXScale="1.0"        <?起始x坐标?>
                android:toXScale="0.1"          <?结束x坐标?>
                android:fromYScale="1.0"        <?起始y坐标?>
                android:toYScale="0.1"          <?结束y坐标?>
                android:pivotX="50%"            <?缩放原点x坐标?>
                android:pivotY="50%"            <?缩放原点y坐标?>
                android:duration="3000"         <?动画持续时间?>
             />
        </set>

    四、在代码中使用AnimationUtils装载xml文件，并生成Animation对象
        Animation animation_alpha = AnimationUtils.loadAnimation(MainActivity.this , R.anim.alpha);
        imageView.startAnimation(animation_alpha);
    五、Animation的实现

public class MainActivity extends Activity
{
    private Button alphaButton = null;
    private Button scaleButton = null;
    private Button rotateButton = null;
    private Button translateButton = null;
    private ImageView imageView = null;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //找到控件
        alphaButton = (Button)findViewById(R.id.alphaBtn);
        scaleButton = (Button)findViewById(R.id.scaleBtn);
        rotateButton = (Button)findViewById(R.id.rotateBtn);
        translateButton= (Button)findViewById(R.id.translateBtn);
        imageView = (ImageView)findViewById(R.id.imageViewId);
        //为控件添加事件
        alphaButton.setOnClickListener(new btnListener());
        scaleButton.setOnClickListener(new btnListener());
        rotateButton.setOnClickListener(new btnListener());
        translateButton.setOnClickListener(new btnListener());
    }

    class btnListener implements OnClickListener
    {

        @Override
        public void onClick(View v)
        {
            // TODO Auto-generated method stub
            switch(v.getId())
            {
                case R.id.alphaBtn:
                    //透明效果
                    Animation animation_alpha = AnimationUtils.loadAnimation(MainActivity.this , R.anim.alpha);
                    imageView.startAnimation(animation_alpha);
                    break;
                case R.id.scaleBtn:
                    //缩放效果
                    Animation animation_scale = AnimationUtils.loadAnimation(MainActivity.this , R.anim.scale);
                    imageView.startAnimation(animation_scale);
                    break;
                case R.id.rotateBtn:
                    //旋转效果
                    Animation animation_rotate = AnimationUtils.loadAnimation(MainActivity.this , R.anim.rotate);
                    imageView.startAnimation(animation_rotate);
                    break;
                case R.id.translateBtn:
                    //移动效果
                    Animation animation_translate = AnimationUtils.loadAnimation(MainActivity.this , R.anim.translate);
                    imageView.startAnimation(animation_translate);
                    break;
                default:
                        break;
            }
        }

    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

    xml文件
    1、alpha.xml

<?xml version="1.0" encoding="utf-8"?>
<set
    xmlns:android=""
    android:interpolator="@android:anim/accelerate_interpolator">

    <alpha
        android:fromAlpha="0.1"
        android:toAlpha="1.0"
        android:duration="3000"
        android:startOffset="500"
        />
</set>

    2、scalse.xml

<?xml version="1.0" encoding="utf-8"?>
<set
    xmlns:android=""
    android:interpolator="@android:anim/accelerate_interpolator">

    <scale
        android:fromXScale="1.0"
        android:toXScale="0.1"
        android:fromYScale="1.0"
        android:toYScale="0.1"
        android:pivotX="50%"
        android:pivotY="50%"
        android:duration="3000"
    />

</set>

    3、rotate.xml

<?xml version="1.0" encoding="utf-8"?>
<set
    xmlns:android=""
    android:interpolator="@android:anim/accelerate_interpolator">

    <rotate
           android:fromDegrees="0"
           android:toDegrees="+350"
           android:pivotX="50%"
           android:pivotY="50%"
           android:duration="3000"
        />

</set>

    4、translate.xml

<?xml version="1.0" encoding="utf-8"?>
<set
    xmlns:android=""
    android:interpolator="@android:anim/accelerate_interpolator"
    >
   <translate

       />

</set>

    布局文件

<RelativeLayout xmlns:android=""
    xmlns: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" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    <Button
        android:id="@+id/alphaBtn"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:text="alpha动画"
        />
    <Button
        android:id="@+id/scaleBtn"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_above="@id/alphaBtn"
        android:text="scale动画"
        />
    <Button
        android:id="@+id/rotateBtn"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_above="@id/scaleBtn"
        android:text="rotate动画"
        />
    <Button
        android:id="@+id/translateBtn"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_above="@id/rotateBtn"
        android:text="translate动画"
        />
    <ImageView
        android:id="@+id/imageViewId"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:layout_centerInParent="true"
        android:layout_marginTop="100dip"
        android:src="@drawable/ic_launcher"
        />
</RelativeLayout>