Android 弧形菜单设计
1.开发环境
Android Studio 3.0
Gradle版本：4.3
开发测试手机分辨率:720 * 1280
2.功能描述
弧形菜单布局使用常规布局模式也可以实现，但在手机分辨率众多，机型繁杂的情况下，这种自定义形状的菜单设计就需要自己精细雕琢。弧形菜单设计在网上文章非常多，本人结合自己设计经验，简单描述该功能重点实现部分，同时大多数文章只是在讲述如果实现自定义布局，而对于如何结合控件缩放实现此功能的文章基本上很难找到。
3.软件界面
横屏布局
纵向布局
自定义弧形菜单，继承ViewGroup，实现onMeasure和onLayout方法，同时为自定义控件添加菜单响应事件。
```
protected void onMeasure(int widthMeasureSpec,int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int measureWidth = measureWidth(widthMeasureSpec);
int measureHeight = measureHeight(heightMeasureSpec);
// 计算自定义的ViewGroup中所有子控件的大小
measureChildren(widthMeasureSpec, heightMeasureSpec);
// 设置自定义的控件MyViewGroup的大小
setMeasuredDimension(measureWidth, measureHeight);
}
protected void onLayout(boolean changed,int l,int t,int r,int b) {
final int childCount = getChildCount();
//计算容器宽度和高度及内圈与外圈半径
int viewWidth = r - l;
int viewHeight = b - t;
int cx = (r + l)/2;
int cy = (t + b)/2;
int mRadius0 =0;
int mRadius1 =0;
mRadius0 = viewHeight/2 -20;//中间背景圆半径
mRadius1 = mRadius0 + (viewWidth/2 - mRadius0)/2;//图标所在圆半径
int iIconSize = mRadius0*2/3;//图标大小
int mIntervalHeight =10;//图标之间间隔高度
if ( (5 * iIconSize +120) > viewWidth)
{
iIconSize = (viewWidth -120)/5;
mRadius0 =3 * iIconSize/2;
}
mIntervalHeight = (viewHeight -2 * mRadius0)/4;
mRadius1 = mRadius0 + (viewWidth/2 - mRadius0)/2;
//确定摆放方向及
int mLeft =0;
// 遍历子View
for (int i =0; i < childCount; i++) {
View childView = getChildAt(i);
// 获得子View的高度
int childViewHeight = childView.getMeasuredHeight();
// 获得子View的宽度
int childViewWidth = childView.getMeasuredWidth();
if ( i ==0)
{
RelativeLayout.LayoutParams params =new RelativeLayout.LayoutParams( mRadius0*2 , mRadius0*2);
childView.setLayoutParams(params);
childView.layout(cx - mRadius0, cy - mRadius0, cx + mRadius0, cy + mRadius0);
}
else if ( i ==1 || i==3 || i==4 || i==6)
{
RelativeLayout.LayoutParams params =new RelativeLayout.LayoutParams( iIconSize , iIconSize);
childView.setLayoutParams(params);
//计算图标所在X位置
int y0 = mIntervalHeight + iIconSize/2;
int x0 = (int)(viewWidth/2 - Math.sqrt( mRadius1 * mRadius1 - (viewHeight/2 - y0) * (viewHeight/2 - y0)));
if ( i==3)
{
y0 = viewHeight - y0;
}
else if ( i==4)
{
x0 = viewWidth - x0;
}
else if ( i ==6)
{
x0 = viewWidth - x0;
y0 = viewHeight - y0;
}
int x = x0 - iIconSize/2;
int y = y0 - iIconSize/2;
childView.layout(x, y, x + iIconSize, y + iIconSize);
}
else if ( i ==2 || i==5 )
{
RelativeLayout.LayoutParams params =new RelativeLayout.LayoutParams( iIconSize , iIconSize);
childView.setLayoutParams(params);
//计算图标所在X位置
int y0 = viewHeight/2;
int x0 = viewWidth/2 - mRadius1;
if ( i ==5)
{
x0 = viewWidth - x0;
}
int x = x0 - iIconSize/2;
int y = y0 - iIconSize/2;
childView.layout(x, y, x + iIconSize, y + iIconSize);
}
else if ( i ==7)
{
RelativeLayout.LayoutParams params =new RelativeLayout.LayoutParams( iIconSize , iIconSize);
childView.setLayoutParams(params);
//计算图标所在X位置
int y0 = viewHeight/2;
int x0 = viewWidth/2;
int x = x0 - iIconSize/2;
int y = y0 - iIconSize/2;
childView.layout(x, y, x + iIconSize, y + iIconSize);
}
}
}
```
