Kevin Learn Android：优惠卷

每日一图.jpg

效果图

01.png

代码

1. 布局文件

activity_coupon.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="16dp"
    tools:context=".ui.CouponActivity">

    <view.CouponDisplayView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/color_tel"
        android:padding="20dp"
        android:orientation="horizontal">
        <ImageView
            android:layout_width="90dp"
            android:layout_height="90dp"
            android:src="@mipmap/image1"
            android:scaleType="centerCrop"/>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:paddingLeft="16dp">
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textSize="18sp"
                android:textColor="@color/white"
                android:textStyle="bold"
                android:text="优惠卷"
                />
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textSize="12sp"
                android:padding="5dp"
                android:textColor="@color/white"
                android:text="编号:11223124123213131"
                />
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textSize="12sp"
                android:padding="5dp"
                android:textColor="@color/white"
                android:text="发行: 2021-07-15"
                />
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textSize="12sp"
                android:paddingLeft="5dp"
                android:paddingTop="5dp"
                android:textColor="@color/white"
                android:text="截止日期:2021-09-07"
                />
        </LinearLayout>
    </view.CouponDisplayView>

</RelativeLayout>

2. 自定义 View

CouponDisplayView.java

/**
 * Created on 2021/7/15 18:40
 *
 * @author Gong Youqiang
 */
public class CouponDisplayView extends LinearLayout {
    private Paint mPaint;
    private float gap = 8;
    private float radius = 10;
    private int circleNum;

    private float remain;

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

    public CouponDisplayView(Context context, AttributeSet attrs) {
        this(context, attrs,0);
    }

    public CouponDisplayView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaint.setDither(true);
        mPaint.setColor(Color.WHITE);
        mPaint.setStyle(Paint.Style.FILL);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        for (int i=0;i<circleNum;i++){
            float x = gap+radius+remain/2+((gap+radius*2)*i);
            canvas.drawCircle(x,0,radius,mPaint);
            canvas.drawCircle(x,getHeight(),radius,mPaint);
        }
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        if (remain==0){
            remain = (int)(w-gap)%(2*radius+gap);
        }
        circleNum = (int) ((w-gap)/(2*radius+gap));
    }
}