Android 自定义view实现动态进度条
效果图：
这个是看了梁肖的demo，根据他的思路自己写了一个，但是我写的这个貌似计算还是有些问题，从上面的图就可以看出来，左侧、顶部、右侧的线会有被截掉的部分，有懂得希望能给说一下，改进一下，这个过程还是有点曲折的，不过还是觉得收获挺多的。比如通动画来进行动态的展示（之前做的都是通过Handler进行更新的所以现在换一种思路觉得特别好），还有圆弧的起止角度，矩形区域的计算等！关于绘制我们可以循序渐进，比如最开始先画圆，然后再画周围的线，最后设置动画部分就可以了。不多说了，上代码了。
代码
自定义View
public class ColorProgressBar extends View{ //下面这两行在本demo中没什么用，只是前几天看别人的代码时学到的按一定尺寸，设置其他尺寸的方式，自动忽略或者学习一下也不错 // private int defaultStepIndicatorNum= (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,40,getResources().getDisplayMetrics()); // int mCircleRadius=0.28f*defaultStepIndicatorNum; //布局的宽高 private int mWidth; private int mHeight; //直径 private int mDiameter=500; //底层圆画笔 private Paint mPaintbg; //顶层圆的画笔 private Paint mPaintft; //周围线的画笔 private Paint mPaintLine; //外层线条的长度 private int mLongItem=dip2px(20); //线条与圆的间距 private int mDistanceItem=dip2px(10); //进度条的最大宽度（取底层进度条与顶层进度条宽度最大的） private int mProgressWidth; //底层圆的颜色 private int mBackColor; //顶层圆的颜色 private int mFrontColor; //底层圆、顶层圆的宽度 private float mBackWidth; private float mFrontWidth; //设置进度 private float currentvalue; //通过动画演示进度 private ValueAnimator animator; private int curvalue; public ColorProgressBar(Context context) { this(context,null,0); } public ColorProgressBar(Context context, AttributeSet attrs) { this(context, attrs,0); } public ColorProgressBar(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); TypedArray ta=context.obtainStyledAttributes(attrs, R.styleable.ColorProgressBar); mBackColor= ta.getColor(R.styleable.ColorProgressBar_back_color, Color.BLACK); mFrontColor=ta.getColor(R.styleable.ColorProgressBar_front_color,mBackColor); mBackWidth=ta.getDimension(R.styleable.ColorProgressBar_back_width,dip2px(10)); mFrontWidth=ta.getDimension(R.styleable.ColorProgressBar_front_width,dip2px(10)); mProgressWidth=mBackWidth>mFrontWidth?(int)mBackWidth:(int)mFrontWidth; //注意释放资源 ta.recycle(); init(); } /** * 都是画笔初始化 */ private void init() { mPaintbg=new Paint(Paint.ANTI_ALIAS_FLAG); mPaintbg.setStrokeWidth(mProgressWidth); mPaintbg.setColor(mBackColor); mPaintbg.setStrokeCap(Paint.Cap.ROUND); mPaintbg.setStyle(Paint.Style.STROKE); mPaintft=new Paint(Paint.ANTI_ALIAS_FLAG); mPaintft.setColor(mFrontColor); mPaintft.setStyle(Paint.Style.STROKE); mPaintft.setStrokeWidth(mFrontWidth); mPaintft.setStrokeCap(Paint.Cap.ROUND); mPaintLine=new Paint(Paint.ANTI_ALIAS_FLAG); mPaintLine.setColor(Color.BLACK); mPaintLine.setStrokeWidth(5); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); // 宽度=高度=（长指针+指针与圆盘的间距+进度条的粗细+半径）*2 Log.e("测量数据","LongItem："+mLongItem+"mDistanceItem:"+mDistanceItem+"mProgressWidth:"+mProgressWidth+"mDiameter:"+mDiameter/2); mWidth=(int)2*(mLongItem+mDistanceItem+mProgressWidth*2+mDiameter/2); mHeight=(int)2*(mLongItem+mDistanceItem+mProgressWidth*2+mDiameter/2); Log.e("自定义View","高度"+mHeight+"宽度"+mWidth); setMeasuredDimension(mWidth,mHeight); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); //绘制底层圆弧，矩形的具体计算见图片 canvas.drawArc(new RectF(mProgressWidth/2+mDistanceItem+mLongItem,mProgressWidth/2+mDistanceItem+mLongItem,mWidth-mProgressWidth/2-mDistanceItem-mLongItem,mHeight-mProgressWidth/2-mDistanceItem-mLongItem),0,360,true,mPaintbg); // SweepGradient gradient=new SweepGradient(); //绘制边缘线 canvas.save(); canvas.rotate(144,mWidth/2,mHeight/2); for(int i=0;i<=30;i++){ canvas.rotate(-9,mWidth/2,mHeight/2); if(i%5==0){ canvas.drawLine(mWidth/2,5,mWidth/2,mLongItem,mPaintbg); }else { canvas.drawLine(mWidth/2,25,mWidth/2,mLongItem,mPaintLine); } } canvas.restore(); //给画笔设置渐变 SweepGradient sweepGradient=new SweepGradient(mWidth/2,mHeight/2,Color.RED,Color.YELLOW); mPaintft.setShader(sweepGradient); //绘制顶层圆弧，currentvalue在改变时呈现动态效果 canvas.drawArc(new RectF(mProgressWidth/2+mDistanceItem+mLongItem,mProgressWidth/2+mDistanceItem+mLongItem,mWidth-mProgressWidth/2-mDistanceItem-mLongItem,mHeight-mProgressWidth/2-mDistanceItem-mLongItem),135,currentvalue,false,mPaintft); mPaintft.setTextSize(100); mPaintft.setTextAlign(Paint.Align.CENTER); //绘制文本 canvas.drawText(String.format("%.0f",currentvalue),mWidth/2,mHeight/2+50,mPaintft); invalidate(); } /** * 设置动画 * @param value */ public void setCurrentValue(float value){ // currentvalue=value; animator=ValueAnimator.ofFloat(currentvalue,value); animator.setDuration(3000); animator.setTarget(currentvalue); animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator valueAnimator) { currentvalue= (float) valueAnimator.getAnimatedValue(); curvalue=curvalue/10; } }); animator.start(); } private int dip2px(float dip){ float density=getContext().getResources().getDisplayMetrics().density; return (int)(dip*density+0.5f); } }
矩形计算
Activity调用
@Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.colorprogressbar); mBtStart1= (Button) findViewById(R.id.bt1); bar1= (ColorProgressBar) findViewById(R.id.cp1); mBtStart1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { bar1.setCurrentValue(270); } }); }
自定义属性
<declare-styleable name="ColorProgressBar"> <attr name="back_color" format="color"></attr> <attr name="front_color" format="color"></attr> <attr name="back_width" format="dimension"></attr> <attr name="front_width" format="dimension"></attr> </declare-styleable>
布局
注意：为了使用自定义属性需要添加一行代码（AS）
xmlns:app=http://schemas.android.com/apk/res-auto
布局
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical"> <Button android:id="@+id/bt1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="start1"/> <com.demo.demo.networkdemo.colorprogressbar.widget.ColorProgressBar android:id="@+id/cp1" android:layout_width="232dp" android:layout_height="match_parent" android:layout_gravity="center_horizontal" app:back_color="@color/colorPrimary" app:front_color="@color/colorAccent" android:background="@mipmap/ic_launcher"/> </LinearLayout>
感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！