自定义滑选框
源码
package demo.rulerbug.www.demo.View;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;
import android.widget.AbsListView;
import android.widget.FrameLayout;
import android.widget.ListView;
import demo.rulerbug.www.demo.app.UIUtils;
import demo.rulerbug.www.demo.utils.LogUtils;
public class MyListView extends ListView {
//字view高度
private int mMinimumHeight;
//控件主题宽度
private int mMeasuredWidth;
//控件主题高度
private int mMeasuredHeight;
//红色画笔
private Paint mRedPaint;
//屏幕等分成上中下三部分
//最上面
private RectF mRecf1;
//中间
private RectF mRecf2;
//最下面
private RectF mRecf3;
//上中分割线
private int mUpDiv;
//中下分割线
private int mDownDiv;
//上下view偏转尺寸
private int off = 100;
//回调接口
private SelectListener listener;
//头布局
private FrameLayout mHeaderView;
//脚布局
private FrameLayout mFooterView;
//记录字view滑动距离，根据这个值确定哪个子view显示在控件中央位置
private int mBottomLine;
//蓝色画笔
private Paint mBluePaint;
private Paint mAlphaPaint;
public MyListView(Context context) {
super(context);
init();
}
public MyListView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public MyListView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
public MyListView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
init();
}
private void init() {
//启动绘制函数（draw()）
setWillNotDraw(false);
//初始化画笔
initPaint();
//初始化显示样式
initLook();
//加入头布局，脚布局
initHeaderAndFooter();
//得到三等分线的底面一根
mBottomLine = getMinimumHeight() * 2;
setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView absListView, int i) {
switch (i) {
case AbsListView.OnScrollListener.SCROLL_STATE_IDLE:
//记录滚动停止后 记录当前item的位置
//得到子view
View selectedView = getChildAt(1);
;//得到下面一个子view的底部距离顶层有多少距离
int bottom = 0;
if (selectedView != null) {
bottom = selectedView.getBottom();
}
//得到看到的第一个子view
int firstVisiblePosition = getFirstVisiblePosition();
//得到最后一个可见子view
int lastVisiblePosition = absListView.getLastVisiblePosition() - 1;
//得到应该选中那个子view
int indext = Math.round((firstVisiblePosition + lastVisiblePosition) / 2.0f);
if (bottom < mBottomLine * 0.8) {
// indext++;
} else {
// 校中偏差
indext--;
}
// LogUtils.e("选中索引" + indext + "最大" + getAdapter().getCount());
//容错处理
if (indext >= getAdapter().getCount() - 1) {
indext = getAdapter().getCount() - 2;
} else if (indext < 0) {
indext = 0;
}
//滑向选中view
smoothScrollToPositionFromTop(indext, 0, 500);
//容错处理
if (indext >= getAdapter().getCount()) {
indext = getAdapter().getCount() - 1;
} else if (indext < 0) {
indext = 0;
}
//把选中索引通知出去
if (listener != null) {
listener.select(indext);
}
break;
}
}
@Override
public void onScroll(AbsListView absListView, int i, int i1, int i2) {
}
});
}
private void initLook() {
setDividerHeight(0);
setHorizontalScrollBarEnabled(false);
setVerticalScrollBarEnabled(false);
}
private void initHeaderAndFooter() {
//添加头布局
mHeaderView = new FrameLayout(getContext());
mHeaderView.setBackgroundColor(Color.TRANSPARENT);
mHeaderView.setMinimumHeight((int) (getMinimumHeight() * 1));
addHeaderView(mHeaderView);
//添加脚布局
mFooterView = new FrameLayout(getContext());
mFooterView.setBackgroundColor(Color.TRANSPARENT);
mFooterView.setMinimumHeight((int) (getMinimumHeight() * 1));
addFooterView(mFooterView);
}
private void initRect() {
int tree_height = mMinimumHeight;
mUpDiv = tree_height;
mDownDiv = tree_height * 2;
mRecf1 = new RectF();
mRecf1.set(0, 0, mMeasuredWidth, mUpDiv);
mRecf2 = new RectF();
mRecf2.set(0, mUpDiv, mMeasuredWidth, mDownDiv);
mRecf3 = new RectF();
mRecf3.set(0, mDownDiv, mMeasuredWidth, mMeasuredHeight);
}
private void initPaint() {
mRedPaint = new Paint();
mRedPaint.setColor(Color.RED);
mRedPaint.setStrokeWidth(2);
mBluePaint = new Paint();
mBluePaint.setColor(Color.BLUE);
mBluePaint.setStrokeWidth(2);
mAlphaPaint = new Paint();
mAlphaPaint.setStrokeWidth(1);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
setMeasuredDimension(widthMeasureSpec, getMinimumHeight() * 3);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
//得到字view高度
mMinimumHeight = getMinimumHeight();
//得到控件宽高
mMeasuredWidth = getMeasuredWidth();
mMeasuredHeight = getMeasuredHeight();
initRect();
off = (int) (mMeasuredWidth * 0.1f);
}
@Override
public void draw(Canvas canvas) {
//绘制顶层画面
canvas.save();
canvas.clipRect(mRecf1);
Matrix matrix1 = new Matrix();
matrix1.setPolyToPoly(new float[]{0, 0, mMeasuredWidth, 0, 0, mUpDiv, mMeasuredWidth, mUpDiv}, 0, new float[]{off, 0, mMeasuredWidth - off, 0, 0, mUpDiv, mMeasuredWidth, mUpDiv}, 0, 4);
canvas.concat(matrix1);
super.draw(canvas);
canvas.restore();
//绘制中层画面
canvas.save();
canvas.clipRect(mRecf2);
super.draw(canvas);
canvas.restore();
//绘制底层画面
canvas.save();
canvas.clipRect(mRecf3);
Matrix matrix3 = new Matrix();
matrix3.setPolyToPoly(new float[]{0, mDownDiv, mMeasuredWidth, mDownDiv, 0, mMeasuredHeight, mMeasuredWidth, mMeasuredHeight}, 0, new float[]{0, mDownDiv, mMeasuredWidth, mDownDiv, off, mMeasuredHeight, mMeasuredWidth - off, mMeasuredHeight}, 0, 4);
canvas.concat(matrix3);
super.draw(canvas);
canvas.restore();
//划出分割线
canvas.drawLine(0, mDownDiv, mMeasuredWidth, mDownDiv, mBluePaint);
canvas.drawLine(0, mUpDiv, mMeasuredWidth, mUpDiv, mBluePaint);
//绘制渐变层
for (int i = 0; i <= mUpDiv; i++) {
int alpha = (mUpDiv - i) * 255 / 10 / mMinimumHeight;
int color = Color.argb(alpha, 0xf, 0xf, 0xf);
mAlphaPaint.setColor(color);
canvas.drawLine(0, i, mMeasuredWidth, i, mAlphaPaint);
}
for (int i = mDownDiv; i <= mMeasuredHeight; i++) {
int alpha = (i - mDownDiv) * 255 / 10 / mMinimumHeight;
LogUtils.e(alpha + "-颜色----------------");
int color = Color.argb(alpha, 0xf, 0xf, 0xf);
mAlphaPaint.setColor(color);
canvas.drawLine(0, i, mMeasuredWidth, i, mAlphaPaint);
}
}
public interface SelectListener {
void select(int i);
}
public void setSelectLisrener(SelectListener lisrener) {
this.listener = lisrener;
lisrener.select(0);
}
}
如何用
xml：
引用时一定要注意加上
minHeight
这是子view的高度
<demo.rulerbug.www.demo.View.MyListView
android:id="@+id/tp_time"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:minHeight="70dp"></demo.rulerbug.www.demo.View.MyListView>
代码：
private MyListView mTpTime;
mTpTime = (MyListView) findViewById(R.id.tp_time);
final ArrayList<String> strings = new ArrayList<>();
for (int i = 1000; i < 1020; i++) {
strings.add("--" + i);
}
myAdapter myAdapter = new myAdapter(strings, this);
mTpTime.setAdapter(myAdapter);
mTpTime.setSelectLisrener(new MyListView.SelectListener() {
@Override
public void select(int i) {
LogUtils.e("选中" + i + "---" + strings.get(i));
}
});