2013.09.22——— android GridView行背景

2013.09.22——— android GridView行背景

package com.sina.show.activity.custom;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.view.ViewGroup;
import android.widget.GridView;

import com.sina.show.R;

/**
 * 设置一行的背景
 *
 * @ClassName: MyGridView 
 * @date 2012-10-29 下午04:25:01 
 *
 */
public class MyGridViewLineBackground extends GridView {
	private static String NAMESPACE_ANDROID = "http://schemas.android.com/apk/res/android";
	private Bitmap mBmp;
	private int mColumnNum;
	private int mRowBgHeight;
	public MyGridViewLineBackground(Context context, android.util.AttributeSet attrs) {
		super(context, attrs);
		mBmp = BitmapFactory.decodeResource(getResources(), R.drawable.room_more_line);  
		//获得列数
		mColumnNum = attrs.getAttributeIntValue(NAMESPACE_ANDROID,"numColumns",3);
		//
		mRowBgHeight = 23;
	}

	@Override
	protected void dispatchDraw(Canvas canvas) {   
		//图片的行高
        int rHeight = ((ViewGroup)getChildAt(0)).getChildAt(0).getHeight();
        int width = getWidth();
        int rowNum = (int)Math.ceil(getChildCount()/(double)mColumnNum);
        //源绘制矩形
        Rect src = new Rect(0,0,mBmp.getWidth(),mBmp.getHeight());
        for(int i=0,y=rHeight-mRowBgHeight; i<rowNum; i++,y += rHeight){
            //目的绘制矩形
            Rect dst = new Rect(0,y,width,y+mRowBgHeight);
            canvas.drawBitmap(mBmp,src,dst,null);
        }
        super.dispatchDraw(canvas);   
	} 
}

使用

<com.sina.show.activity.custom.MyGridViewLineBackground
				    android:layout_width="fill_parent"
				    android:layout_height="wrap_content"
				    android:id="@+id/room_main_bottom_grd_more"
					android:cacheColorHint="#00000000" 
					android:listSelector="#00000000"
					android:layout_weight="1"
					android:fadingEdge="none"
					android:numColumns="3"
					android:layout_marginTop="10dip"
					android:horizontalSpacing="0dip"
					android:paddingLeft="20dip"
        			android:paddingRight="20dip"
				    />