自定义评分条RatingBar

package com.ioc.cn.custom;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

import com.ioc.cn.R;

/**
* Created by Cwm on 2018/3/13.
* 自定义评分条RatingBar
*/

public class RatingBar extends View {

private Bitmap mStarNormal, mStarSelect;
private int mStarCount, SelectCount;

public RatingBar(Context context) {
this(context, null);
}

public RatingBar(Context context, @Nullable AttributeSet attrs) {
this(context, attrs, 0);
}

public RatingBar(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);

TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.RatingBar);
int starNormal = typedArray.getResourceId(R.styleable.RatingBar_starNormal, 0);
int starSelect = typedArray.getResourceId(R.styleable.RatingBar_starSelect, 0);
mStarCount = typedArray.getInt(R.styleable.RatingBar_starCount, 0);
typedArray.recycle();
if (starNormal == 0) {
throw new UnsupportedOperationException("未设置 starNormal 属性");
}
if (starSelect == 0) {
throw new UnsupportedOperationException("未设置 starSelect 属性");
}
if (mStarCount <= 0) {
throw new UnsupportedOperationException("未设置 starCount 属性");
}

mStarNormal = BitmapFactory.decodeResource(getResources(), starNormal);
mStarSelect = BitmapFactory.decodeResource(getResources(), starSelect);

}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
//星星宽度+间隔   星星高度
int width = (mStarNormal.getWidth() * mStarCount)
+ (mStarNormal.getWidth() / 3 * (mStarCount - 1));
int height = mStarNormal.getHeight();

setMeasuredDimension(width, height);
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
for (int i = 0; i < mStarCount; i++) {
int left = 0;//设置星星之间间隔
if (i == 0) {
left = i * mStarNormal.getWidth();//第一个间隔为0
} else {//其余的间隔为当前星星数量/3
left = i * mStarNormal.getWidth() + i * (mStarNormal.getWidth() / 3);
}
if (i < SelectCount) {

canvas.drawBitmap(mStarSelect, left, 0, null);
} else {
canvas.drawBitmap(mStarNormal, left, 0, null);
}

}

}

@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
//            case MotionEvent.ACTION_DOWN://三个事件处理的逻辑都一样
case MotionEvent.ACTION_MOVE:
float x = event.getX();
int number = (int) (x / ((mStarNormal.getWidth()) + (mStarNormal.getWidth() / 3)) + 1);
if (number <= 0) {//判断范围
number = 0;
}
if (number > mStarCount) {
number = mStarCount;
}
if (number == SelectCount) {//判断是否和上次的星星数量一致，优化
return true;
}

SelectCount = number;
invalidate();//刷新事件

}
return true;
}
}

使用
<com.ioc.cn.custom.RatingBar
android:id="@+id/ratingBar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp"
app:starCount="5"
app:starNormal="@drawable/star_normal"
app:starSelect="@drawable/star_selected"
/>