Android自定义View实现五星好评效果

本文实例为大家分享了android实现五星好评效果的具体代码，供大家参考，具体内容如下

这个效果想必大家都非常熟悉，那么android如何自定义实现这种效果呢？

首先自定义属性：

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <declare-styleable name="ratingstar">
    <attr name="starnormal" format="reference"/>
    <attr name="starfocus" format="reference"/>
    <attr name="starnumber" format="integer"/>
  </declare-styleable>
</resources>

下面看看具体实现：

/**
 * created by michael on 2019/11/1.
 */
 
public class ratingstar extends view {
 
  private int normalid;
  private int focusid;
  private bitmap normalimg;
  private bitmap focusimg;
  private int number;
  private int w1;
  private int h1;
  private int marginleft;
  private int margintop;
  private int marginbottom;
  private int marginright;
  private int height;
  private int width;
  private int p;
  private float w0;
  private int i0;
  private int mgrade;
 
  public ratingstar(context context) {
    this(context,null);
  }
 
  public ratingstar(context context, @nullable attributeset attrs) {
    this(context, attrs,0);
  }
 
  public ratingstar(context context, @nullable attributeset attrs, int defstyleattr) {
    super(context, attrs, defstyleattr);
    typedarray array = context.obtainstyledattributes(attrs,r.styleable.ratingstar);
    normalid = array.getresourceid(r.styleable.ratingstar_starnormal,0);
    focusid = array.getresourceid(r.styleable.ratingstar_starfocus,0);
    normalimg = bitmapfactory.decoderesource(getresources(), normalid);
    focusimg = bitmapfactory.decoderesource(getresources(), focusid);
    number = array.getinteger(r.styleable.ratingstar_starnumber,5);
    array.recycle();
    i0 = -1;
 
  }
 
  @override
  protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
    w1 = normalimg.getwidth();
    h1 = normalimg.getheight();
    //中间间隔
    p = 30;
    margintop = 20;
    marginbottom = 20;
    marginleft = 20;
    marginright = 20;
    height = h1 + margintop + marginbottom;
    width = w1 *number+(number-1)*p +marginleft+marginright;
    setmeasureddimension(width, height);
  }
 
  @override
  protected void ondraw(canvas canvas) {
    super.ondraw(canvas);
    for (int i = 0; i < number; i++) {
      if (i <= i0){
        canvas.drawbitmap(focusimg,i*w1+marginleft+i*p,margintop,null);
        mgrade = i+1;
      }else{
        canvas.drawbitmap(normalimg,i*w1+marginleft+i*p,margintop,null);
      }
    }
    log.e("msg","我被调用了！");
 
  }
 
  @override
  public boolean ontouchevent(motionevent event) {
    float x = event.getx();//相对于控件自身的距离
    //event.getrawx() 相对于屏幕的距离
    switch (event.getaction()){
      case motionevent.action_down:
      case motionevent.action_move:
      //case motionevent.action_up:
        w0 = getwidth()/5;
        i0 = (int) (x/w0);
        //性能优化，减少ondraw()调用
        if (mgrade == i0+1){
          return true;
        }
        invalidate();
        break;
    }
    return true;
  }
}

最后看看具体布局中使用：

 <com.example.star.ratingstar
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:starnormal="@mipmap/star_normal"
    app:starfocus="@mipmap/star_selected"
    app:starnumber="5"
    />

 以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。