求助，熬了一夜也没搞定，ImageView的onDraw函数问题

FG2006 2011-11-27 06:48:48

我在程序中继承BaseAdapter为ListView添加了多个ImageView，这个ImageView是根据数据动态生成的波形图，现在只有ListView中的第一个ImageView可以正常的显示出波形图，而其它的都没有，但是我通过打的Log看到，其它的ImageView也调用了onDraw函数，而且数据都是对的，可就是没有画出来，请各位帮助分析一下，下面贴上代码：TestListActivity继承了ListActivity，里面有一个内部类继承自BaseAdapter，MyImageView继承自ImageView，根据传递过来的数据画出波形图，QueueItem就是存放这些数据的，如波形图在屏幕中的位置，y轴各点的位置，x轴是每4个像素一个点。



public class TestListActivity extends ListActivity {



		private ArrayList<QueueItem> list;	

		@Override

		public void onCreate(Bundle savedInstanceState) {

			super.onCreate(savedInstanceState);

			Bundle b = getIntent().getExtras();

			list = (ArrayList<QueueItem>) b.getSerializable("list");

			MyAdapter adapter = new MyAdapter(this);

			setListAdapter(adapter);

		}		

		public final class ViewHolder{

			//public TextView title;

			public MyImageView img;

		}

		

		public class MyAdapter extends BaseAdapter{



			private LayoutInflater mInflater;		

			private Context mContext;

			public MyAdapter(Context context){

				this.mInflater = LayoutInflater.from(context);

				mContext = context;

			}

			public int getCount() {

				return list.size();

			}

			public Object getItem(int position) {

				if(position>list.size())

					return null;

				else

					return list.get(position);

			}

			public long getItemId(int position) {

				return position;

			}



			public View getView(int position, View convertView, ViewGroup parent) {

				

				ViewHolder holder = null;

				if (convertView == null) {			

					holder=new ViewHolder();  				

					convertView = mInflater.inflate(R.layout.image_view, null);

					holder.img = (MyImageView)convertView.findViewById(R.id.image);

					convertView.setTag(holder);

					

				}else {					

					holder = (ViewHolder)convertView.getTag();

				}			



				holder.img.setImageResource(R.drawable.backgroud);

				holder.img.setQueueItem(list.get(position));

				//holder.img.postInvalidate();

				convertView.setTag(holder);

				return convertView;

			}

			

		}

}

MyImageView：



public class MyImageView extends ImageView {

	private Paint paint ;

	private QueueItem queue;

	private int floor=0;

	private int ceil=0;

	private int height = 0;

	private int width = 0;

    private Path path;

    private float scale=0;

    

   public MyImageView(Context context, AttributeSet attrs) {  

	    

        super(context,attrs);   

    }  

   public void setQueueItem(QueueItem queue){

		this.queue = queue;

		floor = queue.getFloor();

		ceil = queue.getCeil();

		DisplayMetrics dm=new DisplayMetrics();	

		dm = this.getContext().getApplicationContext().getResources().getDisplayMetrics();

		width=dm.widthPixels;

		height=dm.heightPixels;

		scale = (float)(ceil-floor)/height;

		Log.d("floor+ceil", Integer.toString(floor)+"+"+Integer.toString(ceil));

		Log.d("width+height", Integer.toString(width)+"+"+Integer.toString(height));

		

		initContextView();

		//buildPath();

		//postInvalidate();

   }

	private void initContextView(){

		setBackgroundColor(Color.WHITE);

		path = new Path();

		paint = new Paint();

		paint.setColor(Color.rgb(24, 142, 198));

		paint.setStrokeWidth(2);

		paint.setStyle(Style.FILL);

	}

	private void buildPath(){

		path.moveTo(0, ceil);

    	Iterator<Integer> iterator = queue.getX().iterator();

    	int i = 4;//x轴

    	int y=0;

    	while(iterator.hasNext()){ 		

    		Integer temp = iterator.next();

    		y = (int)(temp*scale);

    		y = ceil-y;

    		path.lineTo(i, y);

    		//Log.d("i="+i, Integer.toString(y));

    		i+=4;

    	}

    	//Log.d("i="+i, Integer.toString(y));

		path.lineTo(i, ceil);

	}



	@Override

	protected void onDraw(Canvas canvas) {



		buildPath();	

		Log.d("onDraw", Integer.toString(this.floor));

		canvas.drawPath(path, paint);

	}



}

QueueItem：
public class QueueItem implements Serializable{

//private int id;
private int ceil;
private int floor;
private int height;
private int xCount;
private Queue<Integer> x;
public QueueItem(){
this.xCount = 120;
this.height = 200;
this.x = new LinkedList<Integer>();

}
public QueueItem(int xCount){
this.xCount = xCount;
this.x = new LinkedList<Integer>();
this.height = 200;

}

public QueueItem(int xCount,int height){
this.xCount = xCount;
this.x = new LinkedList<Integer>();
this.height = height;

}
public int getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
public int getxCount() {
return xCount;
}
public void setxCount(int xCount) {
this.xCount = xCount;
}
public int getCeil() {
return ceil;
}
public void setCeil(int ceil) {
this.ceil = ceil;
}
public int getFloor() {
return floor;
}
public void setFloor(int floor) {
this.floor = floor;
}
public Queue<Integer> getX() {
return x;
}
public void setX(Queue<Integer> x) {
this.x = x;
}
/* public Queue<Integer> getX() {
return x;
}*/
public void pushX(int xx) {
if(x.size()<=xCount){
if(x.size()==xCount)
x.poll();
x.offer(xx);
}
}

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