在Android开发中，我们经常会用到对商家或者商品的评价，运用星星进行打分。然而在Android系统中自带的打分控件，RatingBar特别不好用，间距和大小无法改变。所以，我就自定义了一个特别好用的打分控件。在项目中可以直接使用，特别简单。下面直接上图：

效果图

实现原理

其实就是自定义View继承LinearLayout ，然后里面动态加了五个ImageView。

实现代码，有详细的注释

在attrs中声明的可以在xml中设置的变量

<declare-styleable name="RatingBar"><!--尺寸值--><attr name="starImageSize" format="dimension" /><!--星星间距--><attr name="starPadding" format="dimension" /><!--星星总数--><attr name="starCount" format="integer" /><!--空白的星星资源文件值--><attr name="starEmpty" format="reference" /><!--满星资源文件值--><attr name="starFill" format="reference" /><!--半星资源文件值--><attr name="starHalf" format="reference" /><!--是否可点击boolean值--><attr name="clickable" format="boolean" /><!--当前进度float值--><attr name="starStep" format="float" /><!--每次进度方式的值，整星还是半星--><attr name="stepSize"><enum name="Half" value="0" /><enum name="Full" value="1" /></attr></declare-styleable>

RatingBar源码

import android.content.Context;import android.content.res.TypedArray;import android.graphics.drawable.Drawable;import android.util.AttributeSet;import android.view.View;import android.widget.ImageView;import android.widget.LinearLayout;import com.kejiang.yuandl.R;import java.math.BigDecimal;/*** Created by dylan on 2015/6/11.* 自定义打分控件RatingBar* 可以自定义星星大小和间距* Correction clickEvent from Xml*/public class RatingBar extends LinearLayout {/*** 是否可点击*/private boolean mClickable;/*** 星星总数*/private int starCount;/*** 星星的点击事件*/private OnRatingChangeListener onRatingChangeListener;/*** 每个星星的大小*/private float starImageSize;/*** 每个星星的间距*/private float starPadding;/*** 星星的显示数量，支持小数点*/private float starStep;/*** 空白的默认星星图片*/private Drawable starEmptyDrawable;/*** 选中后的星星填充图片*/private Drawable starFillDrawable;/*** 半颗星的图片*/private Drawable starHalfDrawable;/*** 每次点击星星所增加的量是整个还是半个*/private StepSize stepSize;/*** 设置半星的图片资源文件** @param starHalfDrawable*/public void setStarHalfDrawable(Drawable starHalfDrawable) {this.starHalfDrawable = starHalfDrawable;}/*** 设置满星的图片资源文件** @param starFillDrawable*/public void setStarFillDrawable(Drawable starFillDrawable) {this.starFillDrawable = starFillDrawable;}/*** 设置空白和默认的图片资源文件** @param starEmptyDrawable*/public void setStarEmptyDrawable(Drawable starEmptyDrawable) {this.starEmptyDrawable = starEmptyDrawable;}/*** 设置星星是否可以点击操作** @param clickable*/public void setClickable(boolean clickable) {this.mClickable = clickable;}/*** 设置星星点击事件** @param onRatingChangeListener*/public void setOnRatingChangeListener(OnRatingChangeListener onRatingChangeListener) {this.onRatingChangeListener = onRatingChangeListener;}/*** 设置星星的大小** @param starImageSize*/public void setStarImageSize(float starImageSize) {this.starImageSize = starImageSize;}public void setStepSize(StepSize stepSize) {this.stepSize = stepSize;}/*** 构造函数* 获取xml中设置的资源文件** @param context* @param attrs*/public RatingBar(Context context, AttributeSet attrs) {super(context, attrs);setOrientation(LinearLayout.HORIZONTAL);TypedArray mTypedArray = context.obtainStyledAttributes(attrs, R.styleable.RatingBar);starImageSize = mTypedArray.getDimension(R.styleable.RatingBar_starImageSize, 20);starPadding = mTypedArray.getDimension(R.styleable.RatingBar_starPadding, 10);starStep = mTypedArray.getFloat(R.styleable.RatingBar_starStep, 1.0f);stepSize = StepSize.fromStep(mTypedArray.getInt(R.styleable.RatingBar_stepSize, 1));starCount = mTypedArray.getInteger(R.styleable.RatingBar_starCount, 5);starEmptyDrawable = mTypedArray.getDrawable(R.styleable.RatingBar_starEmpty);starFillDrawable = mTypedArray.getDrawable(R.styleable.RatingBar_starFill);starHalfDrawable = mTypedArray.getDrawable(R.styleable.RatingBar_starHalf);mClickable = mTypedArray.getBoolean(R.styleable.RatingBar_clickable, true);mTypedArray.recycle();for (int i = 0; i < starCount; ++i) {final ImageView imageView = getStarImageView();imageView.setImageDrawable(starEmptyDrawable);imageView.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {if (mClickable) {//浮点数的整数部分int fint = (int) starStep;BigDecimal b1 = new BigDecimal(Float.toString(starStep));BigDecimal b2 = new BigDecimal(Integer.toString(fint));//浮点数的小数部分float fPoint = b1.subtract(b2).floatValue();if (fPoint == 0) {fint -= 1;}if (indexOfChild(v) > fint) {setStar(indexOfChild(v) + 1);} else if (indexOfChild(v) == fint) {if (stepSize == StepSize.Full) {//如果是满星 就不考虑半颗星了return;}//点击之后默认每次先增加一颗星，再次点击变为半颗星if (imageView.getDrawable().getCurrent().getConstantState().equals(starHalfDrawable.getConstantState())) {setStar(indexOfChild(v) + 1);} else {setStar(indexOfChild(v) + 0.5f);}} else {setStar(indexOfChild(v) + 1f);}}}});addView(imageView);}setStar(starStep);}/*** 设置每颗星星的参数** @return*/private ImageView getStarImageView() {ImageView imageView = new ImageView(getContext());LinearLayout.LayoutParams layout = new LinearLayout.LayoutParams(Math.round(starImageSize), Math.round(starImageSize));//设置每颗星星在线性布局的大小layout.setMargins(0, 0, Math.round(starPadding), 0);//设置每颗星星在线性布局的间距imageView.setLayoutParams(layout);imageView.setAdjustViewBounds(true);imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);imageView.setImageDrawable(starEmptyDrawable);imageView.setMinimumWidth(10);imageView.setMaxHeight(10);return imageView;}/*** 设置星星的个数** @param rating*/public void setStar(float rating) {if (onRatingChangeListener != null) {onRatingChangeListener.onRatingChange(rating);}this.starStep = rating;//浮点数的整数部分int fint = (int) rating;BigDecimal b1 = new BigDecimal(Float.toString(rating));BigDecimal b2 = new BigDecimal(Integer.toString(fint));//浮点数的小数部分float fPoint = b1.subtract(b2).floatValue();//设置选中的星星for (int i = 0; i < fint; ++i) {((ImageView) getChildAt(i)).setImageDrawable(starFillDrawable);}//设置没有选中的星星for (int i = fint; i < starCount; i++) {((ImageView) getChildAt(i)).setImageDrawable(starEmptyDrawable);}//小数点默认增加半颗星if (fPoint > 0) {((ImageView) getChildAt(fint)).setImageDrawable(starHalfDrawable);}}/*** 操作星星的点击事件*/public interface OnRatingChangeListener {/*** 选中的星星的个数** @param RatingCount*/void onRatingChange(float ratingCount);}/*** 星星每次增加的方式整星还是半星，枚举类型* 类似于View.GONE*/public enum StepSize {Half(0), Full(1);int step;StepSize(int step) {this.step = step;}public static StepSize fromStep(int step) {for (StepSize f : values()) {if (f.step == step) {return f;}}throw new IllegalArgumentException();}}}在xml中的用法<com.kejiang.yuandl.view.RatingBarandroid:id="@+id/rb"android:layout_width="360dp"android:layout_height="50dp"app:starCount="5"app:starEmpty="@mipmap/star_grey"app:starFill="@mipmap/star_yellow"app:starHalf="@mipmap/star_half_yellow"app:starImageSize="40dp"app:starPadding="20dp"app:starStep="1.5"app:stepSize="Half"></com.kejiang.yuandl.view.RatingBar>

在Activity中的设置

RatingBar ratingBar= (RatingBar) findViewById(R.id.rb);ratingBar.setClickable(true);//设置可否点击ratingBar.setStar(2.5f);//设置显示的星星个数ratingBar.setStepSize(RatingBar.StepSize.Half);//设置每次点击增加一颗星还是半颗星ratingBar.setOnRatingChangeListener(new RatingBar.OnRatingChangeListener() {@Overridepublic void onRatingChange(float ratingCount) {//点击星星变化后选中的个数Log.d("RatingBar","RatingBar-Count="+ratingCount);}});