30 ClipDrawable

ClipDrawable代表从其它位图上截取一个"图片片段",XML中的根元素为<clip.../>,截取的方向由clipOrientation控制

下面以一个慢慢展开的图片为例

先定义一个ClipDrawable资源文件my_clip.xml

<?xml version="1.0" encoding="utf-8"?>  
<clip xmlns:android="http://schemas.android.com/apk/res/android"   
    android:drawable="@drawable/fengjing"  
    android:clipOrientation="horizontal"  
    android:gravity="center">  
</clip> 

接下来在主界面main.xml中的imageview中引用它

<?xml version="1.0" encoding="utf-8"?>  
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    android:layout_width="fill_parent"  
    android:layout_height="fill_parent"  
    android:orientation="vertical" >  
    <!-- 这里imageView的src定义为clipdrawable资源 -->  
    <ImageView  
        android:id="@+id/image"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:src="@drawable/my_clip" />  
</LinearLayout> 

主界面代码

package WangLi.Resouce.ClipDrawableTest;  
  
import java.util.Timer;  
import java.util.TimerTask;  
  
import android.app.Activity;  
import android.graphics.drawable.ClipDrawable;  
import android.os.Bundle;  
import android.os.Handler;  
import android.os.Message;  
import android.widget.ImageView;  
  
public class ClipDrawableTest extends Activity {  
    /** Called when the activity is first created. */  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
        ImageView imageview = (ImageView)findViewById(R.id.image);  
        //获取图片所显示的ClipDrawble对象  
        final ClipDrawable drawable = (ClipDrawable)imageview.getDrawable();  
        final Handler handler = new Handler()  
        {  
            public void handleMessage(Message msg)  
            {  
                if(msg.what == 0x1233)  
                {  
                    //修改ClipDrawable的level值  
                    drawable.setLevel(drawable.getLevel() +200);  
                }  
            }  
        };  
        final Timer timer = new Timer();  
        timer.schedule(new TimerTask()  
        {  
            public void run()  
            {  
                Message msg = new Message();  
                msg.what = 0x1233;  
                //发送消息,通知应用修改ClipDrawable对象的level值  
                handler.sendMessage(msg);  
                //取消定时器  
                if(drawable.getLevel() >= 10000)  
                {  
                    timer.cancel();  
                }  
            }  
        },0,300);  
    }  
}  

显示的效果就是图片从中间往两边慢慢展开