带有边框的ListView和item

 本文来自 http://blog.csdn.net/manymore13 

想为ListView和item四周添加边框有两种方法：

  1.贴一张带有边框效果的背景图

  2.自定义Draw的方法

第一种方法较第二种方法更耗系统资源，但是用法简单，只需要一张图设置为相应控件的背景即可，而第二种灵活性好些。

这次是实现带有边框的ListView和item，为此写个简单Demo 学习学习

先看下Demo运行效果吧

下面是主要代码，主要是用到Canvas.drawLine(...)代码简单，我就不啰嗦了

BorderListView.java

package com.borderlistview.manymore13;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.DashPathEffect;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ListView;

public class BorderListView extends ListView{

	public BorderListView(Context context) {
		super(context);
	}
	
	public BorderListView(Context context, AttributeSet attrs)
	{
		super(context, attrs);
	}

	
	@Override
	protected void onDraw(Canvas canvas) {

		float width = getWidth();
		float height= getHeight();
		int lineWidth = 10; // 线宽十个像素
 		int grayColor = Color.GRAY;
 		Paint mLinePaint = new Paint();
		mLinePaint.setColor(grayColor);
		mLinePaint.setStyle(Paint.Style.STROKE);
		
		mLinePaint.setAntiAlias(true);
		mLinePaint.setStrokeWidth(lineWidth);

		// 画四周的边框 注意下面的 lineWidth/2 不加的话四周的线可能不一样粗 
		canvas.drawLine(0f, 0+lineWidth/2, width, 0+lineWidth/2, mLinePaint);
		canvas.drawLine(width-lineWidth/2, 0, width-lineWidth/2, height, mLinePaint);
		canvas.drawLine(width-lineWidth/2, height-lineWidth/2, 0, height-lineWidth/2, mLinePaint);
		canvas.drawLine(0+lineWidth/2, height, 0+lineWidth/2, 0,mLinePaint);
		
		 
		super.onDraw(canvas);
		
	}

}

ListViewItem.java   ListView的item 添加虚线和红线

package com.borderlistview.manymore13;

import com.manymore13.MyListview.R;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.DashPathEffect;
import android.graphics.Paint;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.RelativeLayout;
import android.widget.TextView;

 public class ListViewItem extends RelativeLayout{

	private View viewHolder;

	private TextView tvEventName;
	private Context c;

	private FrameLayout leftFrame;
 	
	public ListViewItem(Context context) {
		super(context);
		LayoutInflater flater = LayoutInflater.from(context);
		viewHolder = flater.inflate(R.layout.item, this);
 		getViewAndSetClick();
 		c = context;
 	}
	
 	private void getViewAndSetClick()
	{

		tvEventName = (TextView)viewHolder.findViewById(R.id.eventName);
		leftFrame = (FrameLayout)viewHolder.findViewById(R.id.frame);

	}
	
	public void setEventName(String name)
	{
		tvEventName.setText(name);
	}
	
	public void updateView()
	{
		this.postInvalidate();
	}


    @Override
	protected void dispatchDraw(Canvas canvas) {
 		super.dispatchDraw(canvas);
 		Resources res = getResources();
 		int grayColor = Color.GRAY;
 		int redColor = res.getColor(R.color.red);
 		
 		int leftFramepos = leftFrame.getRight();
 		
 		Paint mLinePaint = new Paint();
		mLinePaint.setColor(redColor);
		mLinePaint.setStyle(Paint.Style.STROKE);
		
 		mLinePaint.setStrokeWidth(2);
		
 		//画两条直线
		canvas.drawLine(leftFramepos+20, 0f, leftFramepos+20, getHeight(), mLinePaint);
		canvas.drawLine(leftFramepos+25, 0f, leftFramepos+25, getHeight(), mLinePaint);
	
		// 画虚线
		mLinePaint.setColor(grayColor);
		DashPathEffect effect = new DashPathEffect(new float[] { 5,5, 5, 5, 5}, 3);
		mLinePaint.setAntiAlias(true);
		mLinePaint.setPathEffect(effect);

		canvas.drawLine(0, getHeight(), getWidth(), getHeight(), mLinePaint);

	}
	
	

}

MyBaseAdaper.java

package com.borderlistview.manymore13;

import java.util.List;

import android.content.Context;
import android.os.Handler;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.BaseAdapter;
import android.widget.ImageView;

public class MyBaseAdaper extends BaseAdapter{
	
	private List<String> list;
	private Context c;
	
	MyBaseAdaper(Context c, List<String> list)
	{
		this.list = list;
		this.c = c;
	}
	@Override
	public int getCount() {
		// TODO Auto-generated method stub
		return list.size();
	}

	@Override
	public Object getItem(int i) {
		// TODO Auto-generated method stub
		return list.get(i);
	}

	@Override
	public long getItemId(int i) {
		// TODO Auto-generated method stub
		return i;
	}

	
 	@Override
	public View getView(int i, View view, ViewGroup viewgroup) {

 		ListViewItem itemView = null ;
		if(view == null){
			itemView = new ListViewItem(c);
		}else{
			itemView = (ListViewItem)view;
		}
		itemView.setEventName(list.get(i));
 		return itemView;
 	}
 	
 	

}

另外，在写本次Demo的时候报了错误，有错就改 Caused by: java.lang.NoSuchMethodException:BorderListView(Context,AttributeSet)

在 BorderListView类中加一个构造函数 搞定

public BorderListView(Context context, AttributeSet attrs)
{
super(context, attrs);
}