一 概述：

最近一直致力于Android自定义VIew的学习，主要在看《android群英传》，还有CSDN博客鸿洋大神和wing大神的一些文章，写的很详细，自己心血来潮，学着写了个实现了类似卫星效果的一个自定义的View，分享到博客上，望各位指点一二。写的比较粗糙，见谅。（因为是在Linux系统下写的，效果图我直接用手机拍的，难看，大家讲究下就看个效果，勿喷）。

先来看个效果图，有点不忍直视：

自定义VIew准备：

（1）创建继承自View的类;

（2）重写构造函数;

（3）定义属性。

（4）重写onMeasure(),onLayout()方法。

好了，废话不说了，准备上菜。

二 相关实现

首先是自定义的View，重写构造函数，我这里是直接继承的VIewGroup，贴上代码：

public MoonView(Context context) { this(context,null); } public MoonView(Context context, AttributeSet attrs) { this(context, attrs,0); } public MoonView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); }

这里需要读取自定义的属性，所以调用含三个参数的构造函数。

自定义的属性，我这里知定义了两个，一个是菜单弧形的半径，还有个是菜单在屏幕的位置，这里可以设置在左上角，左下角，右上角，右下角。代码如下：

<"1.0" encoding="utf-8"?> <resources> <declare-styleable name="MoonAttrs"> <attr name="mRadius" format="integer"></attr><> <attr name="mPosition"><> <enum name="leftTop" value="-2"></enum><> <enum name="leftBottom" value="-1"></enum><> <enum name="rightTop" value="-3"></enum><> <enum name="rightBottom" value="-4"></enum><> </attr> </declare-styleable> </resources>

然后在布局文件里面引用自定义的View，配置属性：

<"1.0" encoding="utf-8"?> <com.example.liujibin.testmyview3.myView.MoonView xmlns:android="http://schemas.android.com/apk/res/android" xmlns:custom="http://schemas.android.com/apk/res/com.example.liujibin.testmyview3" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" custom:mRadius="400" custom:mPosition="rightBottom" > <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@mipmap/sapi_icon_add_account"/> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@mipmap/sapi_icon_add_account"/> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@mipmap/sapi_icon_add_account"/> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@mipmap/sapi_icon_add_account"/> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@mipmap/sapi_icon_add_account"/> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:background="@mipmap/sapi_icon_add_account"/> </com.example.liujibin.testmyview3.myView.MoonView>

最后我们需要在自定义的View类中的构造函数里，获取相关的属性值：

public MoonView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); //获取相关属性 TypedArray ta = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MoonAttrs, defStyleAttr,0); mRaius = ta.getInt(R.styleable.MoonAttrs_mRadius,500); position = ta.getInt(R.styleable.MoonAttrs_mPosition,-1); }

做完以上的准备工作，我们就可以对组件进行测量，布局。

@Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); count = getChildCount()-1; angle = 90/(count-1); int count = getChildCount(); for(int i =0;i< count;i++){ measureChild(getChildAt(i),widthMeasureSpec,heightMeasureSpec); } }

count获取按钮的数量，有一个是中心点，不参与计算，angle是每个按钮离基准线的角度，这里以90度为准，固定在这个范围里面均匀分配。

首先先把中心点固定好位置：

@Override protected void onLayout(boolean b, int i, int i1, int i2, int i3) { if(isChanged){ layoutBottom(); } } private void layoutBottom(){ View view = getChildAt(0); switch (position){ case -1: btml = 0; btmt = getMeasuredHeight() - view.getMeasuredHeight(); btmr = view.getMeasuredWidth(); btmb = getMeasuredHeight(); break; case -2: btml = 0; btmt = 0; btmr = view.getMeasuredWidth(); btmb = view.getMeasuredHeight(); break; case -3: btml = getMeasuredWidth() - view.getMeasuredWidth(); btmt = 0; btmr = getMeasuredWidth(); btmb = view.getMeasuredHeight(); break; case -4: btml = getMeasuredWidth() - view.getMeasuredWidth(); btmt = getMeasuredHeight() - view.getMeasuredHeight(); btmr = getMeasuredWidth(); btmb = getMeasuredHeight(); break; } btmWidth = view.getMeasuredWidth(); btmHeight = view.getMeasuredHeight(); view.setOnClickListener(this); view.layout(btml,btmt,btmr,btmb); }

position的值看属性就明白了，对中心点进行固定位置。并且注册点击事件。

现在开始给剩下的按钮布局，并隐藏按钮：

@Override protected void onLayout(boolean b, int i, int i1, int i2, int i3) { if(isChanged){ layoutBottom(); int count = getChildCount(); for(int k = 0;k < count - 1;k++){ View view = getChildAt(k+1); int childWidth = view.getMeasuredWidth(); int childHeight = view.getMeasuredHeight(); int childX = (int)(mRaius*(Math.sin(angle*(k)*Math.PI/180))); int childY = (int)(mRaius*(Math.cos(angle*(k)*Math.PI/180))); int left = 0; int top = 0; int right = 0; int bottom = 0; switch(position){ case -1: left = childX+btmWidth/2-childWidth/2; top =getMeasuredHeight() - (childY+childHeight/2+btmHeight/2); right = childX+btmWidth/2+childWidth/2; bottom =getMeasuredHeight() - (childY + btmHeight/2) + childHeight/2; break; case -2: left = childX+btmWidth/2-childWidth/2; top =childY-childHeight/2+btmHeight/2; right = childX+btmWidth/2+childWidth/2; bottom = childY + btmHeight/2 + childHeight/2; break; case -3: left = getMeasuredWidth() - (childX+btmWidth/2+childWidth/2); top =childY-childHeight/2+btmHeight/2; right = getMeasuredWidth() - (childX+btmWidth/2+childWidth/2)+childWidth; bottom = childY + btmHeight/2 + childHeight/2; break; case -4: left = getMeasuredWidth() - (childX+btmWidth/2+childWidth/2); top =getMeasuredHeight() - (childY+childHeight/2+btmHeight/2); right = getMeasuredWidth() - (childX+btmWidth/2+childWidth/2)+childWidth; bottom =getMeasuredHeight() - (childY + btmHeight/2) + childHeight/2; break; } view.layout(left,top,right,bottom); view.setVisibility(View.GONE); } } }

现在我们实现点击事件：

@Override public void onClick(View view) { if(isChanged){ int count = getChildCount(); for(int i = 0;i < count - 1;i++){ View childView = getChildAt(i+1); int childX = (int)(mRaius*(Math.sin(angle*(i)*Math.PI/180))); int childY = (int)(mRaius*(Math.cos(angle*(i)*Math.PI/180))); int childWidth = view.getMeasuredWidth(); int childHeight = view.getMeasuredHeight(); int left = 0; int top = 0; TranslateAnimation ta = null; switch(position){ case -1: left = childX+btmWidth/2-childWidth/2; top =getMeasuredHeight() - (childY+childHeight/2+btmHeight/2); ta = new TranslateAnimation(-(left+childView.getMeasuredWidth()),0,getMeasuredHeight()-top,0); break; case -2: left = childX+btmWidth/2-childWidth/2; top =childY-childHeight/2+btmHeight/2; ta = new TranslateAnimation(-(left+childView.getMeasuredWidth()),0,-top,0); break; case -3: left = getMeasuredWidth() - (childX+btmWidth/2+childWidth/2); top =childY-childHeight/2+btmHeight/2; ta = new TranslateAnimation(getMeasuredWidth()-(left+childView.getMeasuredWidth()),0,-top,0); break; case -4: left = getMeasuredWidth() - (childX+btmWidth/2+childWidth/2); top =getMeasuredHeight() - (childY+childHeight/2+btmHeight/2); ta = new TranslateAnimation(getMeasuredWidth()-(left+childView.getMeasuredWidth()),0,getMeasuredHeight()-top,0); break; } ta.setDuration(500); childView.setAnimation(ta); childView.setVisibility(View.VISIBLE); } isChanged = false; }else{ int count = getChildCount(); for(int i = 0;i < count - 1;i++){ View childView = getChildAt(i+1); int childX = (int)(mRaius*(Math.sin(angle*(i)*Math.PI/180))); int childY = (int)(mRaius*(Math.cos(angle*(i)*Math.PI/180))); int childWidth = view.getMeasuredWidth(); int childHeight = view.getMeasuredHeight(); int left = 0; int top = 0; TranslateAnimation ta = null; switch(position){ case -1: left = childX+btmWidth/2-childWidth/2; top =getMeasuredHeight() - (childY+childHeight/2+btmHeight/2); ta = new TranslateAnimation(0,-(left+childView.getMeasuredWidth()),0,getMeasuredHeight()-top); break; case -2: left = childX+btmWidth/2-childWidth/2; top =childY-childHeight/2+btmHeight/2; ta = new TranslateAnimation(0,-(left+childView.getMeasuredWidth()),0,-top); break; case -3: left = getMeasuredWidth() - (childX+btmWidth/2+childWidth/2); top =childY-childHeight/2+btmHeight/2; ta = new TranslateAnimation(0,getMeasuredWidth()-(left+childView.getMeasuredWidth()),0,-top); break; case -4: left = getMeasuredWidth() - (childX+btmWidth/2+childWidth/2); top =getMeasuredHeight() - (childY+childHeight/2+btmHeight/2); ta = new TranslateAnimation(0,getMeasuredWidth()-(left+childView.getMeasuredWidth()),0,getMeasuredHeight()-top); break; } ta.setDuration(500); childView.setAnimation(ta); childView.setVisibility(View.GONE); } isChanged = true; } }

设置点击显示以及隐藏，并且带飘动的动画效果。

四个角落效果如下：

以上所述是小编给大家介绍的Android自定义VIew实现卫星菜单效果浅析，希望对大家有所帮助，如果大家有任何疑问请给我们留言，小编会及时回复大家的。在此也非常感谢大家对查字典教程网的支持！