Android中怎么通過自定義View實現五星好評效果

這篇文章將為大家詳細講解有關Android中怎么通過自定義View實現五星好評效果，文章內容質量較高，因此小編分享給大家做個參考，希望大家閱讀完這篇文章后對相關知識有一定的了解。

首先自定義屬性：

<?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>

下面看看具體實現：

/** * 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 h2;  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();    h2 = normalImg.getHeight();    //中間間隔    p = 30;    marginTop = 20;    marginBottom = 20;    marginLeft = 20;    marginRight = 20;    height = h2 + 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","我被調用了！");   }   @Override  public boolean onTouchEvent(MotionEvent event) {    float x = event.getX();//相對于控件自身的距離    //event.getRawX() 相對于屏幕的距離    switch (event.getAction()){      case MotionEvent.ACTION_DOWN:      case MotionEvent.ACTION_MOVE:      //case MotionEvent.ACTION_UP:        w0 = getWidth()/5;        i0 = (int) (x/w0);        //性能優化，減少onDraw()調用        if (mGrade == i0+1){          return true;        }        invalidate();        break;    }    return true;  }}

最后看看具體布局中使用：

<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"    />

關于Android中怎么通過自定義View實現五星好評效果就分享到這里了，希望以上內容可以對大家有一定的幫助，可以學到更多知識。如果覺得文章不錯，可以把它分享出去讓更多的人看到。