Android自定义View之自定义评价打分控件RatingBar实现自定义星星大小和间距

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

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;

public class RatingBar extends LinearLayout {

private boolean mClickable;

private int starCount;

private onRatingChangeListener onRatingChangeListener;

private float starImageSize;

private float starPadding;

private float starStep;

private Drawable starEmptyDrawable;

private Drawable starFillDrawable;

private Drawable starHalfDrawable;

private StepSize stepSize;

public void setStarHalfDrawable(Drawable starHalfDrawable) {
this.starHalfDrawable = starHalfDrawable;
}

public void setStarFillDrawable(Drawable starFillDrawable) {
this.starFillDrawable = starFillDrawable;
}

public void setStarEmptyDrawable(Drawable starEmptyDrawable) {
this.starEmptyDrawable = starEmptyDrawable;
}

public void setClickable(boolean clickable) {
this.mClickable = clickable;
}

public void setonRatingChangeListener(onRatingChangeListener onRatingChangeListener) {
this.onRatingChangeListener = onRatingChangeListener;
}

public void setStarImageSize(float starImageSize) {
this.starImageSize = starImageSize;
}
public void setStepSize(StepSize stepSize) {
this.stepSize = stepSize;
}

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() {
@Override
public 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);
}

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;
}

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);
}
}

public interface onRatingChangeListener {

void onRatingChange(float ratingCount);
}

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

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() {
@Override
public void onRatingChange(float ratingCount) {//点击星星变化后选中的个数
Log.d("RatingBar","RatingBar-Count="+ratingCount);
}
});