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Android 自定义文本 选择器 PickerView

Android 自定义文本 选择器 PickerView

作者: 小熊_c37d | 来源:发表于2017-06-21 13:37 被阅读0次
    自定义文本选择器
    PickerView.png
    调用showPopupWindow 传入有一个View 上下文Context,文本字符串String[]

    <code>

            String[] strings=new String[new Random().nextInt(50)+10];
            for (int i = 0; i <strings.length; i++) {
                strings[i]="元素"+i;
            }
            pickerViewPop.showPopupWindow(statistics_element, BaseApplication.getInstance().getContext(),strings
            ).setOnPickerViewListen(new PickerViewPop.OnPickerViewListen() {
                @Override
                public void OnConfirm(int index, String text) {
                    statistics_element.setText(text+"");
                }
            });
    

    </code>

    PopupWindow 显示

    <code>

        import android.content.Context;
        import android.graphics.drawable.BitmapDrawable;
        import android.util.Log;
        import android.view.LayoutInflater;
        import android.view.MotionEvent;
        import android.view.View;
        import android.view.ViewGroup;
        import android.widget.PopupWindow;
        import android.widget.Scroller;
        import android.widget.TextView;
    
        import com.app.framework.R;
    
        public class PickerViewPop {
    
            private PopupWindow popupWindow;
    
    
            public PickerViewPop showPopupWindow(View view, Context context, String[] str) {
                // 一个自定义的布局,作为显示的内容
                View contentView = LayoutInflater.from(context).inflate(
                        R.layout.picker_view, null);
                // 设置按钮的点击事件
                setContentView(contentView, str);
    
                popupWindow = new PopupWindow(contentView,
                        ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, true);
    
                popupWindow.setTouchable(true);
    
                popupWindow.setTouchInterceptor(new View.OnTouchListener() {
    
                    @Override
                    public boolean onTouch(View v, MotionEvent event) {
    
                        Log.i("mengdd", "onTouch : ");
    
                        return false;
                        // 这里如果返回true的话,touch事件将被拦截
                        // 拦截后 PopupWindow的onTouchEvent不被调用,这样点击外部区域无法dismiss
                    }
                });
    
                // 如果不设置PopupWindow的背景,无论是点击外部区域还是Back键都无法dismiss弹框
                popupWindow.setBackgroundDrawable(new BitmapDrawable());
    
                // 设置好参数之后再show
                popupWindow.showAsDropDown(view);
    
        
                return this;
            }
            public interface OnPickerViewListen {
                void OnConfirm(int index, String text);
            }
    
            private OnPickerViewListen onPickerViewListen;
    
            public void setOnPickerViewListen(OnPickerViewListen onPickerViewListen) {
                this.onPickerViewListen = onPickerViewListen;
            }
    
            public void setContentView(View contentView, final String[] str) {
                final PickerView pickerView = (PickerView) contentView.findViewById(R.id.picker_view);
                TextView confirm = (TextView) contentView.findViewById(R.id.confirm);
                confirm.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        if(onPickerViewListen!=null){
                            int index=pickerView.getSelectedTextIndex();
                            onPickerViewListen.OnConfirm(index,str[index]);
                            popupWindow.dismiss();
                        }
                    }
                });
                pickerView.setTextString(str);
            }
        }
    

    </code>

    自定义的文本选择器

    <code>

    import android.content.Context;
    import android.graphics.Canvas;
    import android.graphics.Paint;
    import android.support.annotation.Nullable;
    import android.util.AttributeSet;
    import android.view.MotionEvent;
    import android.view.View;
    
    import com.app.framework.utils.DipToPx;
    
    import java.math.BigDecimal;
    
    
    /**
     * 滚动选择器
     * 布局设置的高度必须能被weight 整除, 否则会有偏差
     */
    public class PickerView extends View {
        private String TAG = "PickerView";
        /**
         * 数据
         */
        private String[] strings = new String[]{};
        /**
         * 控件宽度
         */
        private int mViewWidth;
    
        /**
         * 控件高度
         */
        private int mViewHeight;
    
        /**
         * 文本画笔
         */
        private Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    
        /**
         * 中间线画笔
         */
        private Paint mLinePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        /**
         * 中间线边距
         */
        private int linePading = 10;
    
        /**
         * 绘制文字大小
         */
        private int textSezi = 14;
        /**
         * 中间线的厚度
         */
        private float lineWidth = 1;
        /**
         * 选中的颜色
         */
        private int checkedColor = 0xFFFF0000;
        /**
         * 未选中的颜色
         */
        private int notCheckedColor = 0xFF000000;
    
        /**
         * 看见的条目数量,必须奇数
         */
        private int weight = 5;
    
        private int itemHeight;
        /**
         * 当前的位置
         */
        private int index;
    
        /**
         * 默认选中中间位置
         */
        private int defaultIndex = -1;
    
    
        private int checkedIndex = (weight - 1) / 2;
        private float mMoveLen;
    
        public PickerView(Context context) {
            super(context);
            init();
        }
    
        /**
         * 设置默认选中位置
         */
        public void setDefaultIndex(int defaultIndex) {
            this.defaultIndex = defaultIndex;
        }
    
        public PickerView(Context context, @Nullable AttributeSet attrs) {
            super(context, attrs);
            init();
    
        }
    
        public PickerView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
            super(context, attrs, defStyleAttr);
            init();
        }
    
        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            mViewHeight = getMeasuredHeight();
            mViewWidth = getMeasuredWidth();
            itemHeight = mViewHeight / weight;
    
    
            if (defaultIndex == -1) {
                /**设置默认中间位置*/
                defaultIndex = strings.length / 2;
            }
    
            mMoveLen = -itemHeight * (defaultIndex - (weight - 1) / 2);
            this.index = defaultIndex;
        }
    
        /**
         * 设置整个控件可视条目数量
         */
        public void setWeight(int weight) {
            this.weight = weight;
        }
    
        /**
         * 获取选中的位置
         */
        public int getSelectedTextIndex() {
            return index;
        }
    
        /**
         * 设置text文本数组
         */
        public void setTextString(String[] strings) {
            this.strings = strings;
        }
    
        private void setSelectedText(int index) {
            this.index = index;
        }
    
        /**
         * 设置绘制文字大小
         */
        public void setTextSezi(int textSezi) {
            this.textSezi = textSezi;
        }
    
        /**
         * 设置绘制中间线边距
         */
        public void setLinePading(int linePading) {
            this.linePading = linePading;
        }
    
    
        /**
         * 设置中间线的厚度
         */
        public void setLineWidth(float lineWidth) {
            this.lineWidth = lineWidth;
        }
    
        /**
         * 设置选中时的文本颜色
         */
        public void setCheckedColor(int checkedColor) {
            this.checkedColor = checkedColor;
        }
    
        /***设置未选中时的文本颜色*/
        public void setNotCheckedColor(int notCheckedColor) {
            this.notCheckedColor = notCheckedColor;
        }
    
        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            /**绘制文字*/
            drwaText(canvas);
            /**绘制中间线*/
            drwaLine(canvas);
    
        }
    
        /**
         * 绘制文字
         *
         * @param canvas
         */
        private void drwaText(Canvas canvas) {
            for (int i = 0; i < strings.length; i++) {
                /**绘制可视范围文本*/
                if (i + weight -1 > index && i - weight+1 < index) {
    
                    if (i == index) {
                        mPaint.setColor(checkedColor);
                   
                    } else {
                        mPaint.setColor(notCheckedColor);
                    }
    
                    Paint.FontMetrics metrics = mPaint.getFontMetrics();
                    float textHeight = metrics.descent; //文字高度
                    canvas.drawText(strings[i], mViewWidth / 2, itemHeight * (i + 1) - itemHeight / 2 + mMoveLen + textHeight, mPaint);
                }
            }
        }
    
        /**
         * 绘制中间线
         */
        private void drwaLine(Canvas canvas) {
            int pading = DipToPx.dip2px(linePading);
            canvas.drawLine(pading, itemHeight * checkedIndex, getRight() - pading, itemHeight * checkedIndex, mLinePaint);
            canvas.drawLine(pading, itemHeight * (checkedIndex + 1), getRight() - pading, itemHeight * (checkedIndex + 1), mLinePaint);
        }
    
    
        /**
         * 初始化画笔
         */
        private void init() {
            mPaint.setStyle(Paint.Style.FILL);
            mPaint.setTextAlign(Paint.Align.CENTER);//绘制文本横向居中
            mPaint.setTextSize(DipToPx.dip2px(textSezi));
    
    
            mLinePaint.setStyle(Paint.Style.FILL);
            mLinePaint.setTextAlign(Paint.Align.CENTER);
            mLinePaint.setStrokeWidth(lineWidth);
    
        }
    
        /**
         * 更新画笔参数
         */
        public void updatePaint() {
            init();
            invalidate();
        }
    
        @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 doUp(MotionEvent event) {
            float indexes = mMoveLen / itemHeight;
    
            /**四舍五入 来判定离哪个位置较近*/
            BigDecimal dex = new BigDecimal(indexes).setScale(0, BigDecimal.ROUND_HALF_UP);
            float newIndex = dex.floatValue();
            mMoveLen = newIndex * itemHeight;
            int location;
              /*限制角标0的移动范围*/
            if (newIndex >= checkedIndex + 1) {
                mMoveLen = checkedIndex * itemHeight;
    
            }
            /*限制最后一个单位的移动  移动范围*/
            if (newIndex <= -(strings.length - checkedIndex - 1)) {
                mMoveLen = -((strings.length - checkedIndex - 1) * itemHeight);
            }
            //  Log.i("newIndex",newIndex+"");
            /**防止选中角标越界*/
            if (newIndex >= 0) {
                location = (int) (checkedIndex - newIndex);
                if (newIndex >= checkedIndex + 1) {
                    location = 0;
                }
            } else {
                location = (int) (Math.abs(newIndex) + checkedIndex);
                if (location > strings.length - 1) {
                    location = strings.length - 1;
                }
            }
            /**滑动停止的时候设置当前选中的 是第几个*/
            setSelectedText(location);
            invalidate();
        }
    
    
        private void doMove(MotionEvent event) {
    
            int location;
            mMoveLen += (event.getY() - mLastDownY);
            mLastDownY = event.getY();
            float indexes = mMoveLen / itemHeight;
            /**四舍五入 来判定离哪个位置较近*/
            BigDecimal dex = new BigDecimal(indexes).setScale(0, BigDecimal.ROUND_HALF_UP);
            float newIndex = dex.floatValue();
    
    
            /**防止选中角标越界*/
            if (newIndex >= 0) {
                location = (int) (checkedIndex - newIndex);
                if (newIndex >= checkedIndex + 1) {
                    location = 0;
                }
            } else {
                location = (int) (Math.abs(newIndex) + checkedIndex);
                if (location > strings.length - 1) {
                    location = strings.length - 1;
                }
            }
            setSelectedText(location);
            invalidate();
        }
    
        private float mLastDownY;
    
        private void doDown(MotionEvent event) {
            mLastDownY = event.getY();
        }
    
    }
    

    </code>

    布局文件 picker_view

    <code>

        <?xml version="1.0" encoding="utf-8"?>
        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:orientation="vertical" android:layout_width="match_parent"
            android:layout_height="match_parent">
            <com.app.framework.widget.pickerView.PickerView
                android:background="@color/white"
                android:id="@+id/picker_view"
                android:layout_width="100dp"
                android:layout_height="200dp" />
            <TextView
                android:textColor="#111111"
                android:id="@+id/confirm"
                android:gravity="center"
                android:text="确定"
                android:textSize="14sp"
                android:layout_width="100dp"
                android:layout_height="30dp" />
        </LinearLayout>
    

    </code>

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