安卓自定义控件卡券CouponView

来源：互联网发布：成都软件测试工资编辑：程序博客网时间：2024/05/19 04:05

package com.example.couponview;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.widget.RelativeLayout;/** * 卡券控件 * @author wbl * */public class CouponView extends RelativeLayout{private Paint mPaint;//边缘小半圆的半径private float radius = 20;//小半圆之间的间距private float spacing = 20;//左右边距private float paddingLeft;private float paddingRight;//半圆的个数private int numCircle;//控件的高宽度private int height;private int width;private float remain;public CouponView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);//initView(context);}public CouponView(Context context, AttributeSet attrs) {super(context, attrs);initView(context,attrs);}public CouponView(Context context) {super(context);//initView(context);}private void initView(Context context,AttributeSet attrs) {mPaint = new Paint();mPaint.setAntiAlias(true);mPaint.setColor(Color.WHITE);TypedArray ta = context.obtainStyledAttributes(attrs,R.styleable.CouponView);float radius = ta.getDimension(R.styleable.CouponView_radius,20);float spacing = ta.getDimension(R.styleable.CouponView_spacing, 20);setRadius(radius);setSpacing(spacing);ta.recycle();paddingLeft = paddingRight = spacing;}private void setSpacing(float spacing) {this.spacing = spacing;}private void setRadius(float radius) {this.radius = radius;}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);System.out.println("这里");// getWidth在OnCreat的时候得到的是0. 当一个view对象创建时，android并不知道其大小，所以getWidth()和   getHeight()返回的结果是0，真正大小是在计算布局时才会计算.width = this.getWidth();height = this.getHeight();//圆的数量始终比边距数量少一个，所以总长度减去左边距除以2*radius+spacing的值就是圆的数量numCircle = (int) ((width-paddingLeft)/(2*radius+spacing));//除以所有圆和边距的所余下的长度remain = ((width-paddingLeft)%(2*radius+spacing));System.out.println("圆的个数=="+numCircle);System.out.println("remain=="+remain);}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);        //remain/2保证左右两边边距一样float cx = (paddingLeft+radius+remain/2);for(int i=0;i<numCircle;i++){canvas.drawCircle(cx, 0, radius, mPaint);canvas.drawCircle(cx, height, radius, mPaint);cx = (int) (cx+(2*radius+spacing));}}}

在values目录下创建attrs.xml文件

<?xml version="1.0" encoding="utf-8"?><resources>    <declare-styleable name="CouponView">        <attr name="radius" format="dimension"/>        <attr name="spacing" format="dimension"/>          </declare-styleable></resources>

下面是布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:wbl="http://schemas.android.com/apk/res/com.example.couponview"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:gravity="center_horizontal"    android:background="@color/white"    android:paddingTop="20dp"     >    <com.example.couponview.CouponView        android:layout_width="280dp"        android:layout_height="100dp"        android:background="@color/blue"        wbl:radius="10dp"        wbl:spacing="10dp"        android:gravity="center" >        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="卡劵"            android:textColor="@color/white"            android:textSize="30dp" />    </com.example.couponview.CouponView></RelativeLayout>

以下是运行结果

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