自定义音频条形图--p52

package com.zzw.qunyingzhuan2;

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

/**
 * Created by zzw on 2016/7/11.
 * 描述:
 */
public class VoiceBarView extends View {
    private int mRectCount = 10;
    private int offset = 20;
    private int mWidth;
    private int mRectHeight;
    private int mRectWidth;
    private LinearGradient mLinearGradient;

    private Paint paint;

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

    public VoiceBarView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        paint = new Paint();
        paint.setAntiAlias(true);
        paint.setStyle(Paint.Style.FILL);
        paint.setColor(Color.GRAY);
    }

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

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        for (int i = 0; i < mRectCount; i++) {
            float currentHeight = (float) (Math.random() * mRectHeight);
            float left = (float) (mWidth * 0.2 + mRectWidth * i + offset);
            float top = currentHeight;
            float right = (float) (mWidth * 0.2 + mRectWidth * (i + 1));
//            float right = left + mRectWidth;
            float bottom = mRectHeight;
            canvas.drawRect(left, top, right, bottom, paint);
        }
        postInvalidateDelayed(300);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        mWidth = getWidth();
        mRectHeight = getHeight();
        mRectWidth = (int) (mWidth * 0.6 / mRectCount);
        mLinearGradient = new LinearGradient(0, 0, mRectWidth, mRectHeight, Color.YELLOW, Color.BLUE, Shader.TileMode.CLAMP);
        paint.setShader(mLinearGradient);
    }
}