如何在Android中自定义半圆形圆盘滚动选择器？针对这个问题，这篇文章详细介绍了相对应的分析和解答，希望可以帮助更多想解决这个问题的小伙伴找到更简单易行的方法。
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attrs.xml文件代码:
自定义控件的类代码：
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import com.wj.R;
import com.wj.utils.DensityUtil;
import com.wj.utils.ScreenUtils;
import java.util.ArrayList;
import java.util.List;
/**
* @time 2018/6/8
* @author JunJieW
* @since 1376881525@qq.com
* @description 自定义半圆形展示效果转盘选择器控件
*/
public class RingViewHalf extends ViewGroup {
/**
* 上一次滑动的坐标
*/
private float mLastX;
private float mLastY;
/**
* 检测按下到抬起时使用的时间
*/
private long mDownTime;
/**
* 自动滚动线程
*/
private ScrollResetRunnable mScrollResetRunnable;
/**
* 检测按下到抬起时旋转的角度
*/
private float mTmpAngle;
/**
* 每秒最大移动角度
*/
private int mMax_Speed;
/**
* 如果移动角度达到该值，则屏蔽点击
*/
private int mMin_Speed;
/**
* 圆的直径
*/
private int mRadius;
/**
* 判断是否正在自动滚动
*/
private boolean isMove;
/**
* 布局滚动角度
*/
private int mStartAngle = 0;
/**
* 中间条的宽度
*/
private int mCircleLineStrokeWidth;
/**
* 图片内容偏移角度
*/
private int mImageAngle;
/**
* 是否初始化布局
*/
private boolean isChekc = false;
/**
* 布局view
*/
private List mImageList = new ArrayList<>();
/**
* 是否可点击
*/
private boolean isCanClick = true;
/**
* 图片与环之间的padding
*/
private int mPadding;
/**
* 是否是右边居中的图标为选中图标
*/
private boolean is_right_select_icon = true;
/**
* 是否是右边居中的图标为选中图标
*/
private Rect select_icon_rect = new Rect();
//是否能转动
private boolean mCanScrool;
public RingViewHalf(Context context) {
this(context, null, 0);
}
public RingViewHalf(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public RingViewHalf(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
//获取自定义控件设置的值
TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.ringview_half, 0, 0);
mMax_Speed = array.getInteger(R.styleable.ringview_half_max_speed_rh, 300);
mMin_Speed = array.getInteger(R.styleable.ringview_half_min_speed_rh, 3);
mImageAngle = array.getInteger(R.styleable.ringview_half_image_angle_rh, 0);
mPadding = array.getInteger(R.styleable.ringview_half_image_padding_rh, 0);
mCanScrool = array.getBoolean(R.styleable.ringview_half_can_scroll_rh, true);
is_right_select_icon = array.getBoolean(R.styleable.ringview_half_is_right_select_icon_rh, true);
//获取xml定义的资源文件
TypedArray mList = context.getResources().obtainTypedArray(array.getResourceId(R.styleable.ringview_half_list_rh, 0));
int len = mList.length();
if (len > 0) {
for (int i = 0; i < len; i++)
mImageList.add(mList.getResourceId(i, 0));
} else {
mImageList.add(R.mipmap.icon);
mImageList.add(R.mipmap.icon);
mImageList.add(R.mipmap.icon);
}
mList.recycle();
array.recycle();
int [] location =new int [2];
getLocationInWindow(location);
Log.d("locationInWindow",">>>>X=="+location[0]+"y=="+location[1]);
addImgIcon();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (!isChekc) {
initView();
mRadius = getWidth();
isChekc = true;
}
}
/**
* 测量
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(widthMeasureSpec, heightMeasureSpec);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int childCount = this.getChildCount();
for (int i = 0; i < childCount; i++) {
View child = this.getChildAt(i);
this.measureChild(child, widthMeasureSpec, heightMeasureSpec);
child.getMeasuredWidth();
}
}
/**
* 排版布局
*/
private void initView() {
int width = this.getWidth();
int height = this.getHeight();
if (width != height) {
int min = Math.min(width, height);
width = min;
height = min;
}
//不同屏幕分辨率下做不同的处理
float instPadding = 70f;
if (ScreenUtils.getScreenWidth(getContext())<=720){
instPadding = 55f;
}
//图片摆放的圆弧半径
mCircleLineStrokeWidth = getChildAt(0).getMeasuredHeight() + DensityUtil.dip2px(getContext(),instPadding) + mPadding;
//计算图片圆的半径
final int mContent = width / 2 - mCircleLineStrokeWidth / 2;
for (int i = 0; i < getChildCount(); i++) {
View child = this.getChildAt(i);
//计算每个图片摆放的角度
int mAnGle = 360 / mImageList.size() * (i + 1) + mImageAngle;
//获取每个图片摆放的左上角的x和y坐标
float left = (float) (width / 2 + mContent * Math.cos(mAnGle * Math.PI / 180)) - child.getMeasuredWidth() / 2;
float top = (float) (height / 2 + mContent * Math.sin(mAnGle * Math.PI / 180)) - child.getMeasuredHeight() / 2;
/**
* 一四象限
*/
if (getQuadrantByAngle(mAnGle) == 1 || getQuadrantByAngle(mAnGle) == 4) {
// child.setRotation(mAnGle - 270);
/**
* 二三象限
*/
} else {
// child.setRotation(mAnGle + 90);
}
child.layout((int) left, (int) top, (int) left + child.getMeasuredWidth(), (int) top + child.getMeasuredHeight());
}
}
/**
* 添加子控件
*/
private void addImgIcon() {
for (int i = 1; i < mImageList.size() + 1; i++) {
//新建imageview
final ImageView mImageView = new ImageView(getContext());
mImageView.setImageResource(mImageList.get(i - 1));
LayoutParams layoutParams = null;
mImageView.setScaleType(ImageView.ScaleType.FIT_XY);
if (is_right_select_icon){
//右侧icon为选中状态
if (i==mImageList.size()){
mImageView.setAlpha(1f);
layoutParams = new LayoutParams(DensityUtil.dip2px(getContext(),40f), DensityUtil.dip2px(getContext(),40f));
}else {
mImageView.setAlpha(0.5f);
layoutParams = new LayoutParams(DensityUtil.dip2px(getContext(),40f), DensityUtil.dip2px(getContext(),40f));
}
}else {
// 左侧icon为选中状态
if (i==5){
mImageView.setAlpha(1f);
layoutParams = new LayoutParams(DensityUtil.dip2px(getContext(),40f), DensityUtil.dip2px(getContext(),40f));
}else {
mImageView.setAlpha(0.5f);
layoutParams = new LayoutParams(DensityUtil.dip2px(getContext(),40f), DensityUtil.dip2px(getContext(),40f));
}
}
mImageView.setLayoutParams(layoutParams);
final int finalI = i;
//添加点击事件
mImageView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
if (isCanClick) {
// Toast.makeText(getContext(),finalI + " ---", Toast.LENGTH_SHORT).show();
if (mOnLogoItemClick != null)
mOnLogoItemClick.onItemClick(view, finalI - 1);
}
}
});
//添加view
addView(mImageView);
}
//添加view点击事件
setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
if (isCanClick) {
}
}
});
}
/**
* 触摸监听
*/
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
if (mCanScrool) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mLastX = x;
mLastY = y;
mDownTime = System.currentTimeMillis();
mTmpAngle = 0;
// 如果当前已经在快速滚动
if (isMove) {
// 移除快速滚动的回调
removeCallbacks(mScrollResetRunnable);
isMove = false;
return true;
}
break;
case MotionEvent.ACTION_MOVE:
/**
* 获得开始的角度
*/
float start = getAngle(mLastX, mLastY);
/**
* 获得当前的角度
*/
float end = getAngle(x, y);
Log.e("TAG", "start = " + start + " , end =" + end);
// 一四象限
if (getQuadrant(x, y) == 1 || getQuadrant(x, y) == 4) {
mStartAngle += end - start;
mTmpAngle += end - start;
//二三象限
} else {
mStartAngle += start - end;
mTmpAngle += start - end;
}
// 重新布局
getCheck();
break;
case MotionEvent.ACTION_UP:
// 获取每秒移动的角度
float anglePerSecond = mTmpAngle * 1000
/ (System.currentTimeMillis() - mDownTime);
// 如果达到最大速度
if (Math.abs(anglePerSecond) > mMax_Speed && !isMove) {
// 惯性滚动
post(mScrollResetRunnable = new ScrollResetRunnable(anglePerSecond));
return true;
}
// 如果当前旋转角度超过minSpeed屏蔽点击
if (Math.abs(mTmpAngle) > mMin_Speed) {
return true;
}
break;
}
}
return super.dispatchTouchEvent(event);
}
/**
* 获取移动的角度
*/
private float getAngle(float xTouch, float yTouch) {
double x = xTouch - (mRadius / 2d);
double y = yTouch - (mRadius / 2d);
return (float) (Math.asin(y / Math.hypot(x, y)) * 180 / Math.PI);
}
/**
* 根据当前位置计算象限
*/
private int getQuadrant(float x, float y) {
int tmpX = (int) (x - mRadius / 2);
int tmpY = (int) (y - mRadius / 2);
if (tmpX >= 0) {
return tmpY >= 0 ? 4 : 1;
} else {
return tmpY >= 0 ? 3 : 2;
}
}
/**
* 在activity的onCreate方法中获取当前自定义view中在屏幕中的绝对坐标始终为0，
* 改成在onWindowFocusChanged函数中获取即可，这时view都已经加载完成
* 但这里特别注意一点要：如果是fragment种使用该自定义view的话，这里的方法就应该注释掉
* 因为不但获取到的矩形的值是空的，而且当你的fragment执行了跳转的逻辑后，再返回后会发
* 一种特别恶心的异常，你获取到判断选中位置的矩形的left，top，right，bottom的值会和
* 初始化的时候不一样，导致你选中时候的状态出现异常情况，本人已经被坑过，希望后面的同学
* 一定注意吸取教训
*/
@Override
public void onWindowFocusChanged(boolean hasWindowFocus) {
super.onWindowFocusChanged(hasWindowFocus);
getSelectIconReft();
}
//获取选中icon位置的矩形范围
private void getSelectIconReft() {
int [] location = new int [2];
getLocationOnScreen(location);
//计算出右侧选中时图标的位置
if (is_right_select_icon){
//选中的icon动态设置宽高为60，没选中宽高55，这里60/2为选中按钮的宽度或者高度的一半，即中心点
select_icon_rect.left = location[0]+getWidth()-mCircleLineStrokeWidth/2-DensityUtil.dip2px(getContext(),40f)/2;
select_icon_rect.top =(location[1]+getHeight()/2)-DensityUtil.dip2px(getContext(),40f)/2;
select_icon_rect.right = location[0]+getWidth()-mCircleLineStrokeWidth/2+DensityUtil.dip2px(getContext(),40f)/2;
select_icon_rect.bottom = (location[1]+getHeight()/2)+DensityUtil.dip2px(getContext(),40f)/2;
}else {
//计算出左侧选中时图标的位置
//选中的icon动态设置宽高为60，没选中宽高55，这里60/2为选中按钮的宽度或者高度的一半，即中心点
select_icon_rect.left = location[0]+mCircleLineStrokeWidth/2-DensityUtil.dip2px(getContext(),40f)/2;
select_icon_rect.top = (location[1]+getHeight()/2)-DensityUtil.dip2px(getContext(),40f)/2;
select_icon_rect.right = location[0]+mCircleLineStrokeWidth/2+DensityUtil.dip2px(getContext(),40f)/2;
select_icon_rect.bottom = (location[1]+getHeight()/2)+DensityUtil.dip2px(getContext(),40f)/2;
}
Log.d("onFocusChanged","-----getHeight=="+getChildAt(0).getHeight()+";getWidth=="+getChildAt(0).getWidth());
}
/**
* 通过角度判断象限
*/
private int getQuadrantByAngle(int angle) {
if (angle <= 90) {
return 4;
} else if (angle <= 180) {
return 3;
} else if (angle <= 270) {
return 2;
} else {
return 1;
}
}
/**
* 惯性滚动
*/
private class ScrollResetRunnable implements Runnable {
private float angelPerSecond;
public ScrollResetRunnable(float velocity) {
this.angelPerSecond = velocity;
}
public void run() {
//小于20停止
if ((int) Math.abs(angelPerSecond) < 20) {
isMove = false;
return;
}
isMove = true;
// 滚动时候不断修改滚动角度大小
// mStartAngle += (angelPerSecond / 30);
mStartAngle += (angelPerSecond / 40);
//逐渐减小这个值
angelPerSecond /= 1.0666F;
postDelayed(this, 30);
// 重新布局
getCheck();
}
}
/**
* 点击事件接口
*/
public interface OnLogoItemClick {
void onItemClick(View view, int pos);
}
private OnLogoItemClick mOnLogoItemClick;
private OnIconSelectedListener mOnIconSelectedListener;
/**
* 设置点击事件
* @param mOnLogoItemClick
*/
public void addOnItemClick(OnLogoItemClick mOnLogoItemClick) {
this.mOnLogoItemClick = mOnLogoItemClick;
}
/**
* 到选中位置后选中事件接口
*/
public interface OnIconSelectedListener{
void onIconSelected( int pos);
}
/**
* 设置点击事件
* @param mOnIconSelectedListener
*/
public void addOnIconSelectedListener(OnIconSelectedListener mOnIconSelectedListener) {
this.mOnIconSelectedListener = mOnIconSelectedListener;
}
/**
* 旋转圆盘
*/
private void getCheck() {
mStartAngle %= 360;
setRotation(mStartAngle);
//改变选中的icon的状态
setSelectedIcon();
}
//改变选中的icon的状态
private void setSelectedIcon() {
if (select_icon_rect.left==0&&select_icon_rect.top==0){
//fragment中onWindowFocusChanged会出现计算select_icon_rect.left和select_icon_rect.top等于0的情况，
// 所以做下判断，如果为0则重新调用下计算方法
getSelectIconReft();
}
for (int j =0;j然后就是你在activity中根据回调方法获取选中的对象：
//左右侧方法相同，这里列出左侧圆盘获取方法：
view.ringView_half_left.addOnIconSelectedListener { position ->
// ToDo 根据postion从你的list中获取对应的选中的对象的bean类属性即可
}最后贴下布局文件：
//这里是放半圆形转盘选择器上显示的图片list，我这里是用的xml静态传进去的，也可以改为动态方式传递
app:list_rh="@array/zodiac_list"
然后在values下面创建一个arrays.xml文件
- @drawable/zodiac_1
- @drawable/zodiac_2
- @drawable/zodiac_3
- @drawable/zodiac_4
- @drawable/zodiac_5
- @drawable/zodiac_6
- @drawable/zodiac_7
- @drawable/zodiac_8
- @drawable/zodiac_9
- @drawable/zodiac_10
- @drawable/zodiac_11
- @drawable/zodiac_12
关于如何在Android中自定义半圆形圆盘滚动选择器问题的解答就分享到这里了，希望以上内容可以对大家有一定的帮助，如果你还有很多疑惑没有解开，可以关注创新互联行业资讯频道了解更多相关知识。
名称栏目：如何在Android中自定义半圆形圆盘滚动选择器
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