Android自定义竖直方向SeekBar多色进度条

写在前面

因为有这样的一个场景，需要实现竖直方向的多色进度条，然后在网上也找了下，没看到符合需要的，于是自定义了一个，效果如下：

具体实现

本来想定义水平的，然后旋转一下，后来发现还不如直接定义竖直方向来的直接，就直接在竖直方向画了下。

首先讲一下思路，就是通过继承View，然后通过onDraw()方法进行绘制。具体绘制的时候，需要处理一些小细节。

比如，我们需要画一个圆形的滑动块，那么我们的背景色带就不能把整个宽度占满，要不然，小圆块只能和色带一样宽了，效果不是很好看，所以在绘制的时候应该把背景画的宽度小于View的实际宽度。

接下来我要贴代码了：

 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  int h = getMeasuredHeight();
  int w = getMeasuredWidth();
  mRadius = (float) w/2;
  sLeft = w * 0.25f; // 背景左边缘坐标
  sRight = w * 0.75f;// 背景右边缘坐标
  sTop = 0;
  sBottom = h; 
  sWidth = sRight - sLeft; // 背景宽度
  sHeight = sBottom - sTop; // 背景高度
  x = (float) w/2;//圆心的x坐标
  y = (float) (1-0.01*progress)*sHeight;//圆心y坐标
  drawBackground(canvas);
  drawCircle(canvas);
  paint.reset();
 }
 

再看下画背景：

private void drawBackground(Canvas canvas){
  RectF rectBlackBg = new RectF(sLeft, sTop, sRight, sBottom);
  linearGradient=new LinearGradient(sLeft,sTop,sWidth,sHeight,colorArray,null, Shader.TileMode.MIRROR);
  paint.setAntiAlias(true);
  paint.setStyle(Paint.Style.FILL);
  //设置渲染器
  paint.setShader(linearGradient);
  canvas.drawRoundRect(rectBlackBg, sWidth/2, sWidth/2, paint);
}
 

这里使用LinearGradient实现多种颜色渐变，默认初始化定义如下:

 private int endColor=Color.WHITE;
 private int thumbColor=Color.BLACK;
 private int thumbBorderColor=Color.WHITE;
 private int colorArray[]={startColor, middleColor, endColor};
 

然后看下画圆的操作：

 private void drawCircle(Canvas canvas){
  Paint thumbPaint = new Paint();
  y = y < mRadius ? mRadius : y;//判断thumb边界
  y = y > sHeight-mRadius ? sHeight-mRadius : y;
  thumbPaint.setAntiAlias(true);
  thumbPaint.setStyle(Paint.Style.FILL);
  thumbPaint.setColor(thumbColor);
  canvas.drawCircle(x, y, mRadius, thumbPaint);
  thumbPaint.setStyle(Paint.Style.STROKE);
  thumbPaint.setColor(thumbBorderColor);
  thumbPaint.setStrokeWidth(2);
  canvas.drawCircle(x, y, mRadius, thumbPaint);
 }
 

这里通过画布画了一个圆形，内部填充和外边沿。
上面的过程已经可以使效果展示出来了，但是无法操作，我们还需要给它加上事件才行：

 @Override
 public boolean onTouchEvent(MotionEvent event) {
  this.y = event.getY();
  progress= (sHeight-y)/sHeight*100;
  switch(event.getAction()) {
   case MotionEvent.ACTION_DOWN:
    break;
   case MotionEvent.ACTION_UP:
    if (onStateChangeListener!=null){
     onStateChangeListener.onStopTrackingTouch(this, progress);
    }
    break;
   case MotionEvent.ACTION_MOVE:
    if (onStateChangeListener!=null){
     onStateChangeListener.OnStateChangeListener(this, progress);
    }
    setProgress(progress);
    this.invalidate();
    break;
  }

  return true;
 }
 public interface OnStateChangeListener{
  void OnStateChangeListener(View view, float progress);
  void onStopTrackingTouch(View view, float progress);
 }

 public void setOnStateChangeListener(OnStateChangeListener onStateChangeListener){
  this.onStateChangeListener=onStateChangeListener;
 }
 

这里写了个回调接口，然后我们在Activity中就可以接收到相应的滑动进度，进而进行操作，当然，这里我们还得再加一个方法，以便改变seekbar的状态：

 public void setProgress(float progress) {
  this.progress = progress;
  invalidate();
 }
 

到这里，功能基本就OK了，然后我们可以在Activity中去使用它了,下面是布局中的引用：

怎么使用就很简单了：

package com.tfxiaozi.activity.setting;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;

import com.tfxiaozi.R;
import com.tfxiaozi.activity.BaseActivity;
import com.tfxiaozi.utils.ToastUtils;
import com.tfxiaozi.widget.VerticalColorSeekBar;

/**
 * Created by dongqiang on 2016/10/16.
 */
public class ManualSettingActivity extends BaseActivity implements View.OnClickListener, VerticalColorSeekBar.OnStateChangeListener {

 private TextView tvCurrentTemper, tvCurrentBrightness, tvMainTitle;
 private ImageView ivBack;
 private VerticalColorSeekBar vpbInnerTemper;
 private VerticalColorSeekBar vpbBrightness;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_manual_setting);
  initViews();
  initEvents();
  initData();
 }

 private void initViews() {
  tvMainTitle = (TextView) findViewById(R.id.title_main_text);
  tvMainTitle.setText(getString(R.string.manual_setting));
  tvMainTitle.setVisibility(View.VISIBLE);
  ivBack = (ImageView) findViewById(R.id.title_back);
  ivBack.setVisibility(View.VISIBLE);

  tvCurrentTemper = (TextView) findViewById(R.id.tv_current_temper);
  tvCurrentBrightness = (TextView) findViewById(R.id.tv_current_brightness);
  vpbInnerTemper = (VerticalColorSeekBar)findViewById(R.id.vpb_inner_temper);
  vpbBrightness = (VerticalColorSeekBar) findViewById(R.id.vpb_brightness);
  vpbInnerTemper.setColor(Color.RED, Color.YELLOW, Color.GREEN, Color.BLUE, Color.TRANSPARENT);
  vpbBrightness.setColor(Color.BLUE, Color.WHITE, Color.YELLOW, Color.BLUE, Color.TRANSPARENT);
 }

 private void initEvents() {
  ivBack.setOnClickListener(this);
  vpbInnerTemper.setOnStateChangeListener(this);
  vpbBrightness.setOnStateChangeListener(this);
 }

 private void initData() {
  vpbInnerTemper.setProgress(50);
  vpbBrightness.setProgress(70);
 }

 @Override
 public void onClick(View v) {
  switch (v.getId()) {
   case R.id.title_back:
    finish();
    break;
  }
 }

 @Override
 public void OnStateChangeListener(View view, float progress) {

 }

 @Override
 public void onStopTrackingTouch(View view, float progress) {
  int viewId = view.getId();
  switch (viewId) {
   case R.id.vpb_inner_temper:
    if (progress < 0) {
     progress = 0;
    }
    if(progress > 100) {
     progress = 100;
    }
    ToastUtils.showShort(this, "progress= " + progress);
    break;

   case R.id.vpb_brightness:
    if (progress < 0) {
     progress = 0;
    }
    if(progress > 100) {
     progress = 100;
    }
    ToastUtils.showShort(this, "progress1= " + progress);
    break;
  }

 }
}

到这里就结束了，最后还是附上自定义View的整个代码吧：

package com.tfxiaozi.widget;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Shader;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

/**
 * Created by dongqiang on 2016/10/21.
 */
public class VerticalColorSeekBar extends View{

 private static final String TAG = VerticalColorSeekBar.class.getSimpleName();
 private int startColor= Color.BLACK;
 private int middleColor = Color.GRAY;
 private int endColor=Color.WHITE;
 private int thumbColor=Color.BLACK;
 private int thumbBorderColor=Color.WHITE;
 private int colorArray[]={startColor, middleColor, endColor};
 private float x,y;
 private float mRadius;
 private float progress;
 private float maxCount = 100f;
 private float sLeft, sTop, sRight, sBottom;
 private float sWidth,sHeight;
 private LinearGradient linearGradient;
 private Paint paint = new Paint();
 protected OnStateChangeListener onStateChangeListener;

 public VerticalColorSeekBar(Context context) {
  this(context, null);
 }

 public VerticalColorSeekBar(Context context, AttributeSet attrs) {
  super(context, attrs);
 }

 @Override
 protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  super.onMeasure(widthMeasureSpec, heightMeasureSpec);
  setMeasuredDimension(getMeasuredWidth(), getMeasuredHeight());
 }

 public void setColor(int startColor,int middleColor, int endColor,int thumbColor,int thumbBorderColor){
  this.startColor= startColor;
  this.middleColor = middleColor;
  this.endColor= endColor;
  this.thumbColor= thumbColor;
  this.thumbBorderColor= thumbBorderColor;
  colorArray[0] = startColor;
  colorArray[1] = middleColor;
  colorArray[2] = endColor;
 }


 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  int h = getMeasuredHeight();
  int w = getMeasuredWidth();
  mRadius = (float) w/2;
  sLeft = w * 0.25f; // 背景左边缘坐标
  sRight = w * 0.75f;// 背景右边缘坐标
  sTop = 0; 
  sBottom = h; 
  sWidth = sRight - sLeft; // 背景宽度
  sHeight = sBottom - sTop; // 背景高度
  x = (float) w/2;//圆心的x坐标
  y = (float) (1-0.01*progress)*sHeight;//圆心y坐标
  drawBackground(canvas);
  drawCircle(canvas);
  paint.reset();
 }

 private void drawBackground(Canvas canvas){
  RectF rectBlackBg = new RectF(sLeft, sTop, sRight, sBottom);
  linearGradient=new LinearGradient(sLeft,sTop,sWidth,sHeight,colorArray,null, Shader.TileMode.MIRROR);
  paint.setAntiAlias(true);
  paint.setStyle(Paint.Style.FILL);
  //设置渲染器
  paint.setShader(linearGradient);
  canvas.drawRoundRect(rectBlackBg, sWidth/2, sWidth/2, paint);
 }

 private void drawCircle(Canvas canvas){
  Paint thumbPaint = new Paint();
  y = y < mRadius ? mRadius : y;//判断thumb边界
  y = y > sHeight-mRadius ? sHeight-mRadius : y;
  thumbPaint.setAntiAlias(true);
  thumbPaint.setStyle(Paint.Style.FILL);
  thumbPaint.setColor(thumbColor);
  canvas.drawCircle(x, y, mRadius, thumbPaint);
  thumbPaint.setStyle(Paint.Style.STROKE);
  thumbPaint.setColor(thumbBorderColor);
  thumbPaint.setStrokeWidth(2);
  canvas.drawCircle(x, y, mRadius, thumbPaint);
 }

 @Override
 public boolean onTouchEvent(MotionEvent event) {
  this.y = event.getY();
  progress= (sHeight-y)/sHeight*100;
  switch(event.getAction()) {
   case MotionEvent.ACTION_DOWN:
    break;
   case MotionEvent.ACTION_UP:
    if (onStateChangeListener!=null){
     onStateChangeListener.onStopTrackingTouch(this, progress);
    }
    break;
   case MotionEvent.ACTION_MOVE:
    if (onStateChangeListener!=null){
     onStateChangeListener.OnStateChangeListener(this, progress);
    }
    setProgress(progress);
    this.invalidate();
    break;
  }

  return true;
 }


 public interface OnStateChangeListener{
  void OnStateChangeListener(View view, float progress);
  void onStopTrackingTouch(View view, float progress);
 }

 public void setOnStateChangeListener(OnStateChangeListener onStateChangeListener){
  this.onStateChangeListener=onStateChangeListener;
 }

 public void setProgress(float progress) {
  this.progress = progress;
  invalidate();
 }
}

结束

到这里就真的结束啦，就当记录一下吧，然后也希望帮到有需要的人。有更好的实现也可以告诉我哈~

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。