初学Android,使用Drawable资源之使用ClipDrawable资源(十六)

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);
    }
}

运行效果如下

刚开始图片从中间往两边展开

最后展开完整的图片

利用ClipDrawable,还可以做图片进度条