Android实现带有边框的ListView和item的方法

本文实例讲述了android实现带有边框的listview和item的方法。分享给大家供大家参考，具体如下：

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);
}

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希望本文所述对大家android程序设计有所帮助。