Android自定义控件波浪线工具类

做了一个自定义View波浪线,记录下
一,自定义控件介绍
一般android中开发自定义控件包含组合控件，把现有的控件组合起来，加上动画,继承现有控件，做增强功能,继承View，完全自定义控件,继承ViewGroup,完全自定义控件。一般自定义控件有三个重新方法分别是onMeasure(）测量控件，onLayout()摆放控件,onDraw()绘制控件.关于画笔和路径有一个地址详细介绍http://www.open-open.com/lib/view/open1477882828066.html
二,自定义View波浪线就是通过继承View,然后利用paint和path绘制出来,有些问题在代码中有注释方便查看

public class WaveLineView extends View {

    public static final int   DEF_SIZE = 50;
    public static final int   DEF_COLOR = Color.BLACK;
    public static final int   DEF_LITUDE = 10;
    public static final float DEF_WIDTH = 2.0f;
    public static final float DEF_PERIOD = (float) (2 * Math.PI / 180);//Mathi.pi圆周率
    private Path mPath;
    private Paint mPaint;
    private int mLitude;
    private int mColor = DEF_COLOR;
    private float mPeriod;
    private float mWidth = DEF_WIDTH;


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

    public WavyLineView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public WavyLineView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(attrs);
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public WavyLineView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init(attrs);
    }

    /**
     *初始化view控件
     */
    private void init(AttributeSet attrs) {
        TypedArray ta = getContext().obtainStyledAttributes(attrs, R.styleable.WavyLineView);
        mColor = ta.getColor(R.styleable.WavyLineView_strokeColor, DEF_COLOR);
        mPeriod = ta.getFloat(R.styleable.WavyLineView_period, DEF_PERIOD);
        mLitude = ta.getDimensionPixelOffset(R.styleable.WavyLineView_amplitude, DEF_LITUDE);
        mWidth = ta.getDimensionPixelOffset(R.styleable.WavyLineView_strokeWidth, dp2px(getContext(), DEF_WIDTH));
        ta.recycle();
        mPath = new Path(); //创建路径
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);  //创建画笔
        mPaint.setStyle(Paint.Style.STROKE);//设置画笔风格，空心或者实心
        mPaint.setAntiAlias(true);//设置是否抗锯齿
        mPaint.setStrokeCap(Paint.Cap.ROUND);   //设置画笔的类型
        mPaint.setColor(mColor);
        mPaint.setStrokeWidth(dp2px(getContext(), mWidth));//设置画笔宽度

  /** setAntiAlias: 设置画笔的锯齿效果。 
   setColor: 设置画笔颜色 
   setARGB:  设置画笔的a,r,p,g值。 
   setAlpha:  设置Alpha值 
   setTextSize: 设置字体尺寸。 
   setStyle:  设置画笔风格，空心或者实心。 
   setStrokeWidth: 设置空心的边框宽度。 
   getColor:  得到画笔的颜色 
   getAlpha:  得到画笔的Alpha值
   */
    }

    /**
     *测量控件
     */
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        setMeasuredDimension(measureSize(widthMeasureSpec), measureSize(heightMeasureSpec));
    }

    /**
     *绘制控件
     */
    @Override
    protected void onDraw(Canvas canvas) {
        calculatePath();
        canvas.drawPath(mPath, mPaint);
    }
    //MeasureSpec包含Mode和Size,其中AT_Most为wrap,Exactly设置确切参数,Unspecified设置为match
    private int measureSize(int measureSpec) {
        int defSize = dp2px(getContext(), DEF_SIZE);
        int specSize = MeasureSpec.getSize(measureSpec);
        int specMode = MeasureSpec.getMode(measureSpec);
        int result = 0;
        switch (specMode) {
            case MeasureSpec.UNSPECIFIED:
            case MeasureSpec.AT_MOST:
                result = Math.min(defSize, specSize);
                break;
            case MeasureSpec.EXACTLY:
                result = specSize;
                break;
        }
        return result;
    }
    //绘制从左上角开始根据上下左右绘制
    private void calculatePath() {
        mPath.reset();
        float y;
        float left = getPaddingLeft();
        float right = getMeasuredWidth() - getPaddingRight();
        float top = getPaddingTop();
        float bottom = getMeasuredHeight() - getPaddingBottom();
        mPath.moveTo(left, (top + bottom) / 2);
        //通过正弦函数绘制x,y路径
        for (float x = 0; x <= right; x = x+1) {
            y = (float) (mLitude * Math.sin(mPeriod * x) + (top + bottom) / 2);  //Math.sin正
            mPath.lineTo(x + left, y);
        }
    }

    /**
     *设置波浪上下波动
     */
    public void setLitude(int amplitude) {
        this.mLitude = amplitude;
        invalidate();
    }

    /**
     *设置波浪频率
     */
    public void setPeriod(float T) {
        this.mPeriod = T;
        invalidate();//调用此方法重新绘制view
    }

    /**
     *设置波浪颜色
     */
    public void setColor(int color) {
        this.mColor = color;
        mPaint.setColor(mColor);
        invalidate();
    }

    /**
     *设置波浪宽度
     */
    public void setWidth(float strokeWidth) {
        this.mWidth = strokeWidth;
        mPaint.setStrokeWidth(mWidth);
        invalidate();
    }

    /**
     *dp->px工具方法
     */
    public static int dp2px(Context context, float dipValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dipValue * scale + 0.5f);
    }
}

三,在Activity中的使用,直接全类名在布局文件中使用
1,布局文件

    <com.tstest.www.waveline.WaveLineView
        android:id="@+id/wavyLineView"
        android:layout_width="match_parent"
        android:layout_height="200dp"/>

2,activity中代码直接调用相应方法

  final WavyLineView mWavyLineView = (WavyLineView) findViewById(R.id.wavyLineView);
        float initPeriod = (float) (2 * Math.PI / 180);
        int initLitude = 30;
        int initWidth = 3;
           mWavyLineView .setPeriod(initPeriod);//设置左右频率
           mWavyLineView .setLitude(initLitude);//设置上下波动
           mWavyLineView .setColor(Color.BLACK);//设置颜色
           mWavyLineView .setWidth(dp2px(this, initWidth));