自制WheelView沉浸式菜单及Dialog样式Activity

自制一个简单的WheelView控件，配合Dialog样式的Activity使用

为什么不直接用Dialog呢？

因为感觉Dialog有时候传值会很麻烦，而且写起来也不方便。用Activity仿的话就很方便，效果也不错。

当然用Dialog也是可以的，具体根据项目需求和个人习惯而定。

效果图如下：

那么直接贴核心代码，源码我会在博客底部发链接

Dialog样式的Activity布局：

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:layout_gravity="center"     android:layout_margin="80dp">      <TextView         android:id="@+id/rate_tv"         android:layout_width="fill_parent"         android:layout_height="45dp"         android:background="@drawable/more_top_nor"         android:gravity="center"         android:text="选项"         android:drawableBottom="@drawable/cell_cut_line"         android:textColor="@android:color/black"         android:textSize="18sp" />      <com.lg.wheelviewdemo.PickerView         android:id="@+id/pickerview"         android:layout_below="@id/rate_tv"         android:background="@drawable/more_content_nor"         android:layout_width="match_parent"         android:layout_height="150dp" />      <TextView         android:onClick="onClick"         android:layout_width="fill_parent"         android:layout_height="45dp"         android:drawableTop="@drawable/cell_cut_line"         android:layout_below="@id/pickerview"         android:text="确定"         android:textColor="@android:color/black"         android:textSize="18sp"         android:gravity="center"         android:background="@drawable/more_bottom_nor"/>  </RelativeLayout>

PickerView也就是自制的WheelView，代码如下：

/**  * 滚动选择器  */ public class PickerView extends View {      public static final String TAG = "PickerView";     /**      * text之间间距和minTextSize之比      */     public static final float MARGIN_ALPHA = 2.3f;     /**      * 自动回滚到中间的速度      */     public static final float SPEED = 2;      private List<String> mDataList;     /**      * 选中的位置，这个位置是mDataList的中心位置，一直不变      */     private int mCurrentSelected;     private Paint mPaint;      private float mMaxTextSize = 30;     private float mMinTextSize = 15;      private float mMaxTextAlpha = 255;     private float mMinTextAlpha = 100;      private int mViewHeight;     private int mViewWidth;      private float mLastDownY;     /**      * 滑动的距离      */     private float mMoveLen = 0;     private boolean isInit = false;     private onSelectListener mSelectListener;     private Timer timer;     private MyTimerTask mTask;      Handler updateHandler = new Handler() {          @Override         public void handleMessage(Message msg) {             if (Math.abs(mMoveLen) < SPEED) {                 mMoveLen = 0;                 if (mTask != null) {                     mTask.cancel();                     mTask = null;                     performSelect();                 }             } else                 // 这里mMoveLen / Math.abs(mMoveLen)是为了保有mMoveLen的正负号，以实现上滚或下滚                 mMoveLen = mMoveLen - mMoveLen / Math.abs(mMoveLen) * SPEED;             invalidate();         }      };      public PickerView(Context context) {         super(context);         init();     }      public PickerView(Context context, AttributeSet attrs) {         super(context, attrs);         init();     }      public void setOnSelectListener(onSelectListener listener) {         mSelectListener = listener;     }      private void performSelect() {         if (mSelectListener != null)             mSelectListener.onSelect(mDataList.get(mCurrentSelected));     }      public void setData(List<String> datas) {         mDataList = datas;         mCurrentSelected = datas.size() / 2;         invalidate();     }      /**      * 选择选中的item的index      *      * @param selected      */     public void setSelected(int selected) {         mCurrentSelected = selected;         int distance = mDataList.size() / 2 - mCurrentSelected;         if (distance < 0)             for (int i = 0; i < -distance; i++) {                 moveHeadToTail();                 mCurrentSelected--;             }         else if (distance > 0)             for (int i = 0; i < distance; i++) {                 moveTailToHead();                 mCurrentSelected++;             }         invalidate();     }      /**      * 选择选中的内容      *      * @param mSelectItem      */     public void setSelected(String mSelectItem) {         for (int i = 0; i < mDataList.size(); i++)             if (mDataList.get(i).equals(mSelectItem)) {                 setSelected(i);                 break;             }     }      private void moveHeadToTail() {         String head = mDataList.get(0);         mDataList.remove(0);         mDataList.add(head);     }      private void moveTailToHead() {         String tail = mDataList.get(mDataList.size() - 1);         mDataList.remove(mDataList.size() - 1);         mDataList.add(0, tail);     }      @Override     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {         super.onMeasure(widthMeasureSpec, heightMeasureSpec);         mViewHeight = getMeasuredHeight();         mViewWidth = getMeasuredWidth();         // 按照View的高度计算字体大小         mMaxTextSize = mViewHeight / 4.0f;         mMinTextSize = mMaxTextSize / 2f;         isInit = true;         invalidate();     }      private void init() {         timer = new Timer();         mDataList = new ArrayList<String>();         mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);         mPaint.setStyle(Style.FILL);         mPaint.setTextAlign(Align.CENTER);         mPaint.setColor(Color.WHITE);     }      @Override     protected void onDraw(Canvas canvas) {         super.onDraw(canvas);         // 根据index绘制view         if (isInit)             drawData(canvas);     }      private void drawData(Canvas canvas) {         // 先绘制选中的text再往上往下绘制其余的text         float scale = parabola(mViewHeight / 4.0f, mMoveLen);         float size = (mMaxTextSize - mMinTextSize) * scale + mMinTextSize;         mPaint.setTextSize(size);         mPaint.setColor(this.getResources().getColor(android.R.color.black));         mPaint.setAlpha((int) ((mMaxTextAlpha - mMinTextAlpha) * scale + mMinTextAlpha));         // text居中绘制，注意baseline的计算才能达到居中，y值是text中心坐标         float x = (float) (mViewWidth / 2.0);         float y = (float) (mViewHeight / 2.0 + mMoveLen);         FontMetricsInt fmi = mPaint.getFontMetricsInt();         float baseline = (float) (y - (fmi.bottom / 2.0 + fmi.top / 2.0));          canvas.drawText(mDataList.get(mCurrentSelected), x, baseline, mPaint);         // 绘制上方data         for (int i = 1; (mCurrentSelected - i) >= 0; i++) {             drawOtherText(canvas, i, -1);         }         // 绘制下方data         for (int i = 1; (mCurrentSelected + i) < mDataList.size(); i++) {             drawOtherText(canvas, i, 1);         }      }      /**      * @param canvas      * @param position 距离mCurrentSelected的差值      * @param type     1表示向下绘制，-1表示向上绘制      */     private void drawOtherText(Canvas canvas, int position, int type) {         float d = (float) (MARGIN_ALPHA * mMinTextSize * position + type                 * mMoveLen);         float scale = parabola(mViewHeight / 4.0f, d);         float size = (mMaxTextSize - mMinTextSize) * scale + mMinTextSize;         mPaint.setTextSize(size);         mPaint.setAlpha((int) ((mMaxTextAlpha - mMinTextAlpha) * scale + mMinTextAlpha));         float y = (float) (mViewHeight / 2.0 + type * d);         FontMetricsInt fmi = mPaint.getFontMetricsInt();         float baseline = (float) (y - (fmi.bottom / 2.0 + fmi.top / 2.0));         canvas.drawText(mDataList.get(mCurrentSelected + type * position),                 (float) (mViewWidth / 2.0), baseline, mPaint);     }      /**      * 抛物线      *      * @param zero 零点坐标      * @param x    偏移量      * @return scale      */     private float parabola(float zero, float x) {         float f = (float) (1 - Math.pow(x / zero, 2));         return f < 0 ? 0 : f;     }      @Override     public boolean onTouchEvent(MotionEvent event) {         switch (event.getActionMasked()) {             case MotionEvent.ACTION_DOWN:                 doDown(event);                 break;             case MotionEvent.ACTION_MOVE:                 doMove(event);                 break;             case MotionEvent.ACTION_UP:                 doUp(event);                 break;         }         return true;     }      private void doDown(MotionEvent event) {         if (mTask != null) {             mTask.cancel();             mTask = null;         }         mLastDownY = event.getY();     }      private void doMove(MotionEvent event) {          mMoveLen += (event.getY() - mLastDownY);          if (mMoveLen > MARGIN_ALPHA * mMinTextSize / 2) {             // 往下滑超过离开距离             moveTailToHead();             mMoveLen = mMoveLen - MARGIN_ALPHA * mMinTextSize;         } else if (mMoveLen < -MARGIN_ALPHA * mMinTextSize / 2) {             // 往上滑超过离开距离             moveHeadToTail();             mMoveLen = mMoveLen + MARGIN_ALPHA * mMinTextSize;         }          mLastDownY = event.getY();         invalidate();     }      private void doUp(MotionEvent event) {         // 抬起手后mCurrentSelected的位置由当前位置move到中间选中位置         if (Math.abs(mMoveLen) < 0.0001) {             mMoveLen = 0;             return;         }         if (mTask != null) {             mTask.cancel();             mTask = null;         }         mTask = new MyTimerTask(updateHandler);         timer.schedule(mTask, 0, 10);     }      class MyTimerTask extends TimerTask {         Handler handler;          public MyTimerTask(Handler handler) {             this.handler = handler;         }          @Override         public void run() {             handler.sendMessage(handler.obtainMessage());         }      }      public interface onSelectListener {         void onSelect(String text);     }

Dialog样式Activity：

private PickerView pickerView; private List<String> mDatas;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_wheel);     pickerView = (PickerView) findViewById(R.id.pickerview);     mDatas=new ArrayList<>();     for (int i = 1; i < 60; i++) {         mDatas.add(""+i);     }     pickerView.setData(mDatas);     pickerView.setSelected(MainActivity.num-1);     pickerView.setOnSelectListener(new PickerView.onSelectListener() {         @Override         public void onSelect(String text) {             MainActivity.num=Integer.parseInt(text);         }     }); }  public void onClick(View view){     MainActivity.tv.setText("当前选择  "+MainActivity.num);     finish(); }

接下来要给Activity换上Dialog样式

在styles.xml中加上

<style name="MyDialogStyle" parent="Theme.AppCompat.Dialog">     <item name="android:windowFrame">@null</item>     <item name="windowNoTitle">true</item>     <!-- 边框 -->     <item name="android:windowIsFloating">true</item>     <!-- 是否浮现在activity之上 -->     <item name="android:windowIsTranslucent">true</item>     <!-- 半透明 -->     <item name="android:windowNoTitle">true</item>     <!-- 无标题 -->     <item name="android:windowBackground">@android:color/transparent</item>     <!-- 背景透明 -->     <item name="android:backgroundDimEnabled">true</item>     <!-- 模糊 -->  </style>

AndroidManifest.xml中：

<activity android:name=".WheelActivity"     android:theme="@style/MyDialogStyle"/>

源码地址： http://down.51cto.com/data/2223518