【Android】动态渐变色的扇形

来源：互联网发布：有招聘淘宝主播的吗编辑：程序博客网时间：2024/05/02 02:28
http://bbs.csdn.net/topics/390746097
看到CSDN这一论坛的问题，好奇地去把它解决了。看了一下时间都是一年前了。
MyActivity.java
package com.example.abcd;import android.annotation.SuppressLint;import android.app.Activity;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.DashPathEffect;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.Paint.Style;import android.graphics.Path;import android.graphics.PathEffect;import android.graphics.RectF;import android.graphics.Shader;import android.graphics.SweepGradient;import android.os.Bundle;import android.view.View;public class MyActivity extends Activity{    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(new SampleView(this));    }    @SuppressLint("DrawAllocation")private static class SampleView extends View {        private Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);        private float mRotate;        private Matrix mMatrix = new Matrix();        private Shader mShader;        public SampleView(Context context) {            super(context);            setFocusable(true);            setFocusableInTouchMode(true);            float x = 160;            float y = 100;            mShader = new SweepGradient(x, y, new int[] {0xFF09F68C,                                                  0xFFB0F44B,                                                  0xFFE8DD30,                                                  0xFFF1CA2E,                                                  0xFFFF902F,                                                  0xFFFF6433}, null);            mPaint.setShader(mShader);            mPaint.setStyle(Style.STROKE);            PathEffect effect = new DashPathEffect(new float[] { 2, 3, 2,3}, 1);            mPaint.setPathEffect(effect);            mPaint.setStrokeWidth(40);        }        public void getArc(Canvas canvas,float o_x,float o_y,float r,        float startangel,float endangel,Paint paint){        RectF rect = new RectF(o_x - r, o_y - r, o_x + r, o_y + r);        Path path = new Path();                path.moveTo(o_x,o_y);                path.lineTo((float)(o_x+r*Math.cos(startangel*Math.PI/180))                  , (float)(o_y+r*Math.sin(startangel*Math.PI/180)));                path.lineTo((float)(o_x+r*Math.cos(endangel*Math.PI/180))                  , (float)(o_y+r*Math.sin(endangel*Math.PI/180)));                path.addArc(rect, startangel, endangel-startangel);                canvas.clipPath(path);                canvas.drawCircle(o_x, o_y, r, paint);        }        @Override         protected void onDraw(Canvas canvas) {            Paint paint = mPaint;            float x = 160;            float y = 100;            canvas.drawColor(Color.WHITE);            mMatrix.setRotate(mRotate, x, y);            mShader.setLocalMatrix(mMatrix);            mRotate += 3;            if (mRotate >= 360) {                mRotate = 0;            }            invalidate();            getArc(canvas,x,y,80,135,405,paint);        }    }}
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