话不多说 直接上代码 这里采用的是自定View
public class RatingBar extends View {
// 正常、半个和选中的星星
private Bitmap mStarNormal, mStarHalf, mStarSelected;
//星星的总数
private int mStartTotalNumber = 5;
//选中的星星个数
private float mSelectedNumber;
// 星星之间的间距
private int mStartDistance;
// 是否画满
private Status mStatus = Status.FULL;
// 星星的宽高
private float mStarWidth;
private float mStarHeight;
// 星星选择变化的回调
private OnStarChangeListener mOnStarChangeListener;
// 是不是要画满,默认不画半个的
private boolean isFull;
// 画笔
private Paint mPaint = new Paint();
// 用于判断是绘制半个，还是全部
private enum Status {
FULL, HALF
}
public void setOnStarChangeListener(OnStarChangeListener OnStarChangeListener) {
this.mOnStarChangeListener = OnStarChangeListener;
}
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 array = context.obtainStyledAttributes(attrs, R.styleable.RatingBar);
// 未选中的图片资源
int starNormalId = array.getResourceId(R.styleable.RatingBar_starEmptyRes, 0);
if (starNormalId == 0) {
throw new IllegalArgumentException("请设置属性 starNormal");
}
mStarNormal = BitmapFactory.decodeResource(getResources(), starNormalId);
// 选中一半的图片资源
int starHalfId = array.getResourceId(R.styleable.RatingBar_starHalfRes, 0);
if (starHalfId != 0) {
mStarHalf = BitmapFactory.decodeResource(getResources(), starHalfId);
}
// 选中全部的图片资源
int starSelectedId = array.getResourceId(R.styleable.RatingBar_starSelectedRes, 0);
if (starSelectedId == 0) {
throw new IllegalArgumentException("请设置属性 starSelected");
}
mStarSelected = BitmapFactory.decodeResource(getResources(), starSelectedId);
// 如果没设置一半的图片资源，就用全部的代替
if (starHalfId == 0) {
mStarHalf = mStarSelected;
}
mStartTotalNumber = array.getInt(R.styleable.RatingBar_startTotalNumber, mStartTotalNumber);
mSelectedNumber = array.getFloat(R.styleable.RatingBar_selectedNumber, mSelectedNumber);
mStartDistance = (int) array.getDimension(R.styleable.RatingBar_starDistance, 0);
mStarWidth = array.getDimension(R.styleable.RatingBar_starWidth, 0);
mStarHeight = array.getDimension(R.styleable.RatingBar_starHeight, 0);
isFull = array.getBoolean(R.styleable.RatingBar_starIsFull, true);
array.recycle();
// 如有指定宽高，获取最大值 去改变星星的大小（星星是正方形）
int starWidth = (int) Math.max(mStarWidth, mStarHeight);
if (starWidth > 0) {
mStarNormal = resetBitmap(mStarNormal, starWidth);
mStarSelected = resetBitmap(mStarSelected, starWidth);
mStarHalf = resetBitmap(mStarHalf, starWidth);
}
// 计算一半还是全部（小数部分小于等于0.5就只是显示一半）
if (!isFull) {
int num = (int) mSelectedNumber;
if (mSelectedNumber <= (num + 0.5f)) {
mStatus = Status.HALF;
}
}
}
/**
* 设置全部选中的图片
*
* @param bitmap
*/
public void allImage(Bitmap bitmap) {
mStarSelected = bitmap;
int starWidth = (int) Math.max(mStarWidth, mStarHeight);
if (starWidth > 0) {
mStarNormal = resetBitmap(mStarNormal, starWidth);
mStarSelected = resetBitmap(mStarSelected, starWidth);
mStarHalf = resetBitmap(mStarHalf, starWidth);
}
invalidate();
}
/**
* 设置选中一半的图片
*
* @param bitmap
*/
public void mStarHalf(Bitmap bitmap) {
mStarHalf = bitmap;
int starWidth = (int) Math.max(mStarWidth, mStarHeight);
if (starWidth > 0) {
mStarNormal = resetBitmap(mStarNormal, starWidth);
mStarSelected = resetBitmap(mStarSelected, starWidth);
mStarHalf = resetBitmap(mStarHalf, starWidth);
}
invalidate();
}
/**
* 如果用户设置了图片的宽高，就重新设置图片
*/
public Bitmap resetBitmap(Bitmap bitMap, int startWidth) {
// 得到新的图片
return Bitmap.createScaledBitmap(bitMap, startWidth, startWidth, true);
}
/**
* 设置选中星星的数量
*/
public void setSelectedNumber(int selectedNumber) {
if (selectedNumber >= 0 && selectedNumber <= mStartTotalNumber) {
this.mSelectedNumber = selectedNumber;
invalidate();
}
}
/**
* 设置星星的总数量
*/
public void setStartTotalNumber(int startTotalNumber) {
if (startTotalNumber > 0) {
this.mStartTotalNumber = startTotalNumber;
invalidate();
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// 用正常的一个星星图片去测量高
int height = getPaddingTop() + getPaddingBottom() + mStarNormal.getHeight();
// 宽 = 星星的宽度*总数 + 星星的间距*（总数-1） +padding
int width = getPaddingLeft() + getPaddingRight() + mStarNormal.getWidth() * mStartTotalNumber + mStartDistance * (mStartTotalNumber - 1);
setMeasuredDimension(width, height);
}
@Override
protected void onDraw(Canvas canvas) {
// 循环绘制
for (int i = 0; i < mStartTotalNumber; i++) {
float left = getPaddingLeft();
// 从第二个星星开始，给它设置星星的间距
if (i > 0) {
left = getPaddingLeft() + i * (mStarNormal.getWidth() + mStartDistance);
}
float top = getPaddingTop();
// 绘制选中的星星
if (i < mSelectedNumber) {
// 比当前选中的数量小
if (i < mSelectedNumber - 1) {
canvas.drawBitmap(mStarSelected, left, top, mPaint);
} else {
// 在这里判断是不是要绘制满的
if (mStatus == Status.FULL) {
canvas.drawBitmap(mStarSelected, left, top, mPaint);
} else {
canvas.drawBitmap(mStarHalf, left, top, mPaint);
}
}
} else {
// 绘制正常的星星
canvas.drawBitmap(mStarNormal, left, top, mPaint);
}
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
//减少绘制
case MotionEvent.ACTION_MOVE:
// 获取用户触摸的x位置
float x = event.getX();
// 一个星星占的宽度
int startWidth = getWidth() / mStartTotalNumber;
// 计算用户触摸星星的位置
int position = (int) (x / startWidth + 1);
if (position < 0) {
position = 0;
}
if (position > mStartTotalNumber) {
position = mStartTotalNumber;
}
// 计算绘制的星星是不是满的
float result = x - startWidth * (position - 1);
Status status;
// 结果大于一半就是满的
if (result > startWidth * 0.5f) {
// 满的
status = Status.FULL;
} else {
// 一半的
status = Status.HALF;
}
if (isFull) {
status = Status.FULL;
}
//减少绘制
if (mSelectedNumber != position || status != mStatus) {
mSelectedNumber = position;
mStatus = status;
invalidate();
if (mOnStarChangeListener != null) {
position = (int) (mSelectedNumber - 1);
// 选中的数量：满的就回调（1.0这种），一半就（0.5这种）
float selectedNumber = status == Status.FULL ? mSelectedNumber
: (mSelectedNumber - 0.5f);
mOnStarChangeListener.OnStarChanged(selectedNumber,
position < 0 ? 0 : position);
}
}
break;
}
return true;
}
// 回调监听（选中的数量，位置）
public interface OnStarChangeListener {
void OnStarChanged(float selectedNumber, int position);
}
}
自定义属性
<declare-styleable name="RatingBar">
<!--未选中-->
<attr name="starEmptyRes" format="reference" />
<!--选中半个-->
<attr name="starHalfRes" format="reference" />
<!--选中全部-->
<attr name="starSelectedRes" format="reference" />
<!--星星的总数-->
<attr name="startTotalNumber" format="integer" />
<!--默认选中的数量 -->
<attr name="selectedNumber" format="float" />
<!--星星的间距-->
<attr name="starDistance" format="dimension" />
<!--星星的宽度-->
<attr name="starWidth" format="dimension" />
<!--星星的高度-->
<attr name="starHeight" format="dimension" />
<!--是不是只画整个星星，不画半个-->
<attr name="starIsFull" format="boolean" />
</declare-styleable>
xml 配置
<com.demo.mvp_demo.ui.shop.RatingBar
android:id="@+id/rb"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
app:starHeight="30dp"
app:starWidth="30dp"
app:selectedNumber="0.0"
app:starDistance="15dp"
app:starEmptyRes="@drawable/no"
app:starHalfRes="@drawable/twoban"
app:starIsFull="false"
app:starSelectedRes="@drawable/two" />
在activity里 rb指的是 RatingBar rb;
大概就是这个样子 具体的需求 需要根据UI提供图来.