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Android实现卡券效果

2017-02-26  本文已影响290人  Android开发哥

效果图

效果图

先说一下原理,卡券的实现是拓展了LinearLayout的,然后凹凸的效果是通过画圆的方式来画出来的,只要控制位置,就能够画出半圆的效果。

原理图

原理图

编码

attrs.xml属性文件

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <declare-styleable name="CustomContainer">
        <attr name="mColor" format="color" />
        <attr name="mGap" format="dimension" />
        <attr name="mHalfRadius" format="dimension" />
    </declare-styleable>

</resources>

CustomContainer.java文件

package com.example.customview;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.LinearLayout;

public class CustomContainer extends LinearLayout {
    
    private int     mRadius;
    private int     mGap;
    private int     mColor;
    private Paint   mPaint;
                    
    public CustomContainer(Context context) {
        this(context, null);
    }
    
    public CustomContainer(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }
    
    public CustomContainer(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        
        TypedArray ta = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CustomContainer, defStyleAttr, 0);
        
        int n = ta.getIndexCount();
        
        for (int i = 0; i < n; i++) {
            int attr = ta.getIndex(i);
            switch (attr) {
                case R.styleable.CustomContainer_mColor:
                    mColor = ta.getColor(attr, Color.TRANSPARENT);
                    break;
                case R.styleable.CustomContainer_mGap:
                    mGap = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, ta.getDimension(attr, 3),
                            getResources().getDisplayMetrics());
                    break;
                case R.styleable.CustomContainer_mHalfRadius:
                    mRadius = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, ta.getDimension(attr, 20),
                            getResources().getDisplayMetrics());
                    break;
                    
                default:
                    break;
            }
        }
        
        ta.recycle();
        /**
         * 上面是初始化属性参数...不想说啦!!!
         */
        
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaint.setStyle(Paint.Style.FILL);
        mPaint.setColor(mColor);
        /**
         * 初始化画笔
         */
    }
    
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        
        /**
         * 下面就是计算啦,没有意外的话,博客会给一张图来解析的
         */
        
        int n = (mGap + getWidth()) / (2 * mRadius + mGap);
        /**
         * 2*mRadius*n+(n-1)*mGap=geiWidth()转化而来
         */
        
        int centerTopY = 0;
        int centerBottomY = getHeight();
        
        for (int i = 0; i < n; i++) {
            int centerX = 2 * mRadius * (i + 1) + i * mGap;
            canvas.drawCircle(centerX, centerTopY, mRadius, mPaint);
            canvas.drawCircle(centerX, centerBottomY, mRadius, mPaint);
        }
        
    }
}

布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#fff"
    tools:context="com.example.customview.Main5Activity" >

    <com.example.customview.CustomContainer
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:background="#ffbb33"
        android:padding="20dp"
        app:mColor="#fff"
        app:mGap="15dp"
        app:mHalfRadius="5dp" >

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center" >

            <ImageView
                android:id="@+id/img"
                android:layout_width="100dp"
                android:layout_height="100dp"
                android:src="@drawable/jpg" />

            <TextView
                android:id="@+id/caption"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="20dp"
                android:layout_toRightOf="@id/img"
                android:text="韩国美女卡券"
                android:textColor="#666666"
                android:textSize="18sp" />

            <TextView
                android:id="@+id/text1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignLeft="@id/caption"
                android:layout_below="@id/caption"
                android:layout_marginTop="10dp"
                android:text="秒杀价:50元"
                android:textColor="#ff0000"
                android:textSize="22sp" />

            <TextView
                android:id="@+id/text2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentRight="true"
                android:layout_below="@id/text1"
                android:layout_marginLeft="3dp"
                android:layout_marginTop="10dp"
                android:text="原价:150元"
                android:textColor="#999999"
                android:textSize="14sp" />
        </RelativeLayout>
    </com.example.customview.CustomContainer>

</RelativeLayout>
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