Android 自定义SeekBar 实现分段显示不同背景颜色
在最近的开发工作中，要实现一个调色板的进度条，SeekBar要分成10段显示不同颜色，功夫不负有心人，终于实现了这个功能，下面分享给大家
示例图：
1.自定义SeekBar
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.os.Build;
import android.util.AttributeSet;
import android.widget.SeekBar;
/**
*
* @time 2020/6/4 18:32
* <p>
* 类描述：自定义多颜色的SeekBar
*/
public class MulticolourSeekBar extends SeekBar {
/**
* 画笔
*/
private Paint mMulticlourPaint;
/**
* 刻度线的个数,等分数等于刻度线的个数加1
*/
private int mMulticlourCount = 9;
/**
* 每条刻度线的宽度
*/
private int mMulticlourWidth = 2;
/**
* 刻度线的颜色
*/
private int mMulticlourColor = Color.WHITE;
/**
* 滑块上面是否要显示刻度线
*/
private boolean isShowTopOfThumb = false;
public MulticolourSeekBar(Context context) {
super(context);
init();
}
public MulticolourSeekBar(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public MulticolourSeekBar(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
/**
* 初始化
*/
private void init() {
//创建绘制刻度线的画笔
mMulticlourPaint = new Paint();
mMulticlourPaint.setColor(mMulticlourColor);
mMulticlourPaint.setAntiAlias(true);
//Api21及以上调用，去掉滑块后面的背景
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
setSplitTrack(false);
}
}
/**
* 重写onDraw方法绘制刻度线
*
* @param canvas
*/
@Override
protected synchronized void onDraw(Canvas canvas) {
super.onDraw(canvas);
//极限条件校验
if (getWidth() <= 0 || mMulticlourCount <= 0) {
return;
}
//获取每一份的长度
// int length = (getWidth() - getPaddingLeft() - getPaddingRight() - mMulticlourCount * mMulticlourWidth) / (mMulticlourCount + 1);
int length = (getWidth() - getPaddingLeft() - getPaddingRight()) / (mMulticlourCount + 1);
//计算刻度线的顶部坐标和底部坐标
int rulerTop = getHeight() / 2 - getMinimumHeight() / 2;
int rulerBottom = rulerTop + getMinimumHeight();
//获取滑块的位置信息
Rect thumbRect = null;
if (getThumb() != null) {
thumbRect = getThumb().getBounds();
}
//绘制刻度线
// for (int i = 1; i <= mMulticlourCount; i++) {
// //计算刻度线的左边坐标和右边坐标
// int rulerLeft = i * length + getPaddingLeft();
// int rulerRight = rulerLeft + mMulticlourWidth;
//
// //判断是否需要绘制刻度线
// if (!isShowTopOfThumb && thumbRect != null && rulerLeft - getPaddingLeft() > thumbRect.left && rulerRight - getPaddingLeft() < thumbRect.right) {
// continue;
// }
//
// //进行绘制
// canvas.drawRect(rulerLeft, rulerTop, rulerRight, rulerBottom, mMulticlourPaint);
// }
for (int i = 0; i <= mMulticlourCount; i++) {
int left = getPaddingLeft() + i * length;
int right = left + length;
if (i % 3 == 0) {
mMulticlourPaint.setColor(Color.RED);
} else if (i % 3 == 1) {
mMulticlourPaint.setColor(Color.YELLOW);
} else {
mMulticlourPaint.setColor(Color.BLUE);
}
if (i == 0) {
canvas.drawCircle(getPaddingLeft() + 10, 20, 10, mMulticlourPaint);
left += 10;
canvas.drawRect(left, 10, right, 30, mMulticlourPaint);
} else if (i == mMulticlourCount) {
right -= 10;
canvas.drawRect(left, 10, right, 30, mMulticlourPaint);
canvas.drawCircle(right, 20, 10, mMulticlourPaint);
} else {
canvas.drawRect(left, 10, right, 30, mMulticlourPaint);
}
}
}
/**
* 设置刻度线的个数
*
* @param mRulerCount
*/
public void setRulerCount(int mRulerCount) {
this.mMulticlourCount = mRulerCount;
requestLayout();
}
/**
* 设置刻度线的宽度，单位(px)
*
* @param mRulerWidth
*/
public void setRulerWidth(int mRulerWidth) {
this.mMulticlourWidth = mRulerWidth;
requestLayout();
}
/**
* 设置刻度线的颜色
*
* @param mRulerColor
*/
public void setRulerColor(int mRulerColor) {
this.mMulticlourColor = mRulerColor;
if (mMulticlourPaint != null) {
mMulticlourPaint.setColor(mRulerColor);
requestLayout();
}
}
/**
* 滑块上面是否需要显示刻度线
*
* @param isShowTopOfThumb
*/
public void setShowTopOfThumb(boolean isShowTopOfThumb) {
this.isShowTopOfThumb = isShowTopOfThumb;
requestLayout();
}
}
2.activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<com.xinrui.view.MulticolourSeekBar
android:id="@+id/seek_bar"
android:layout_width="350px"
android:layout_height="wrap_content"
android:background="@null"
android:maxHeight="20px"
android:minHeight="20px"
android:max="100"
android:progress="5"
android:progressDrawable="@drawable/shape_progress_drawable"
android:thumb="@drawable/shape_thumb_icon"
android:thumbOffset="-2px"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
3.shape_progress_drawable.xml
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@android:id/background">
<shape>
<solid android:color="#e1e8f0" />
<size android:height="8px" />
<corners android:radius="8px" />
</shape>
</item>
<item android:id="@android:id/progress">
<clip>
<shape>
<gradient
android:endColor="@android:color/transparent"
android:startColor="@android:color/transparent" />
<size android:height="8px" />
<corners android:radius="8px" />
</shape>
</clip>
</item>
</layer-list>
4.shape_thumb_icon.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<size
android:width="5px"
android:height="40px" />
<solid android:color="@android:color/widget_edittext_dark" />
</shape>