【Android自定义View】随机数按钮

来源：互联网发布：博鼎软件科技有限公司编辑：程序博客网时间：2024/05/23 07:22

参考了多个大神的博客，自己也就做了个。

自定义一个控件，一般需要准备以下内容

1.设置对应属性

2.继承View（一般情况下，需求不一样也可以是别的）

3.重写几个函数

做完以上三点，基本一个个性化的控件就完成了

先来第一步

<?xml version="1.0" encoding="utf-8"?><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:custom="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent" android:layout_height="match_parent">    <com.tools.CT        android:layout_width="wrap_content"        android:layout_height="wrap_content"        custom:Ctext="你好"        android:padding="10dp"        android:layout_centerInParent="true"        custom:Ccolor="#555555"        custom:Csize="20dp"        /></LinearLayout>

其中

com.tools.CT 部分就是自定义控件的布局部分

注意：

xmlns:custom="http://schemas.android.com/apk/res-auto"

是必不可少的部分，这也是前提

而com.tools.CT 就是指向继承View的CT类

package com.tools;//import android.app.Activity;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Rect;import android.util.AttributeSet;import android.util.TypedValue;import android.view.View;//import android.view.View;//import android.widget.TextView;import com.example.administrator.myapplication.R;import java.util.HashSet;import java.util.Random;import java.util.Set;/** * Created by Administrator on 2015/9/12. */public class CT extends View{    private String ctext;    private int ccolor;    private int csize;    private Rect mbound;    private Paint mpaint;    public CT(Context context, AttributeSet attrs){       this(context,attrs,0);    }    public CT(Context context){        this(context,null);    }    public CT(Context context,AttributeSet attrs,int style){        super(context,attrs,style);        TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CT, style, 0);        int n = a.getIndexCount();        for (int i = 0; i < n; i++)        {            int attr = a.getIndex(i);            switch (attr)            {                case R.styleable.CT_Ctext:                    ctext = a.getString(attr);                    break;                case R.styleable.CT_Ccolor:                    // 默认颜色设置为黑色                    ccolor = a.getColor(attr, Color.BLACK);                    break;                case R.styleable.CT_Csize:                    // 默认设置为16sp，TypeValue也可以把sp转化为px                    csize = a.getDimensionPixelSize(attr, (int) TypedValue.applyDimension(                            TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));                    break;            }        }        a.recycle();        /**         * 获得绘制文本的宽和高         */        mpaint = new Paint();        mpaint.setTextSize(csize);        // mPaint.setColor(mTitleTextColor);        mbound = new Rect();        mpaint.getTextBounds(ctext, 0, ctext.length(), mbound);        this.setOnClickListener(new OnClickListener()        {            @Override            public void onClick(View v)            {                ctext = randomText();                postInvalidate();            }        });    }    private String  randomText(){        Random random = new Random();        Set<Integer> set = new HashSet<Integer>();        while (set.size() < 4)        {            int randomInt = random.nextInt(10);            set.add(randomInt);        }        StringBuffer sb = new StringBuffer();        for (Integer i : set)        {            sb.append("" + i);        }        return sb.toString();    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        int widthMode = MeasureSpec.getMode(widthMeasureSpec);        int widthSize = MeasureSpec.getSize(widthMeasureSpec);        int heightMode = MeasureSpec.getMode(heightMeasureSpec);        int heightSize = MeasureSpec.getSize(heightMeasureSpec);        int width;        int height ;        if (widthMode == MeasureSpec.EXACTLY)        {            width = widthSize;        } else        {            mpaint.setTextSize(csize);            mpaint.getTextBounds(ctext, 0, ctext.length(), mbound);            float textWidth = mbound.width();            int desired = (int) (getPaddingLeft() + textWidth + getPaddingRight());            width = desired;        }        if (heightMode == MeasureSpec.EXACTLY)        {            height = heightSize;        } else        {            mpaint.setTextSize(csize);            mpaint.getTextBounds(ctext, 0, ctext.length(), mbound);            float textHeight = mbound.height();            int desired = (int) (getPaddingTop() + textHeight + getPaddingBottom());            height = desired;        }        setMeasuredDimension(width, height);    }    @Override    protected void onDraw(Canvas canvas) {        mpaint.setColor(Color.BLUE);        canvas.drawRect(0,0,getMeasuredWidth(),getMeasuredHeight(),mpaint);        mpaint.setColor(ccolor);        canvas.drawText(ctext,getWidth()/2-mbound.width()/2,getHeight()/2+mbound.height()/2,mpaint);    }}

其中

重写

onMeasure 和 onDraw 是重写的主要内容,包含着属性的设置

</pre><pre name="code" class="java">

<pre style="background-color:#2b2b2b;color:#a9b7c6;font-family:'宋体';font-size:9.0pt;"><span style="color:#cc7832;">this</span>.setOnClickListener(<span style="color:#cc7832;">new </span>OnClickListener(){    <span style="color:#bbb529;">@Override</span><span style="color:#bbb529;">    </span><span style="color:#cc7832;">public void </span><span style="color:#ffc66d;">onClick</span>(View v)    {        <span style="color:#9876aa;">ctext </span>= randomText()<span style="color:#cc7832;">;</span><span style="color:#cc7832;">        </span>postInvalidate()<span style="color:#cc7832;">;</span><span style="color:#cc7832;">    </span>}})<span style="color:#cc7832;">;</span>

其中加入点击监听，以此响应随机函数

进而随机显示内容

从而完成随机按钮

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