前言
不知不觉，春分已过两天。万物复苏，居住附近的看桃花也开艳了，路边的垂柳，也绿了。怎奈，这两天天气忽变，有了一些倒春寒的感觉，好冷。近几偶然听闻，同事裁员，愿2019一切顺利。
RadialGradient 说明
类继承关系
构造函数
public RadialGradient(float centerX, float centerY, float radius,
@ColorInt int centerColor, @ColorInt int edgeColor, @NonNull TileMode tileMode)
- (centerX,centerY)圆心x,y座标点。
- radius 渲染半径。
- centerColor 渲染圆心颜色。
- engeColor 渲染圆边缘颜色。
- tileMode 平铺模式（重复，镜像，边缘拉伸）
public RadialGradient(float centerX, float centerY, float radius,
@NonNull @ColorInt int colors[], @Nullable float stops[],
@NonNull TileMode tileMode)
该构造函数和上个构造函数区别
- colors[] 颜色数组，至少两个元素，可设置放射渲染的多种过度颜色。
- stops[] 数组和颜色数组对应，设置各个颜色的渲染起始位置。可以为null（颜色均分）。
代码示例
基本使用
package com.xol.widget;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RadialGradient;
import android.graphics.Shader;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;
/**
* Created by wwzhang on 2019/3/22
*/
public class RadialGradientView extends View {
private Paint mPaint;
private Shader mShader;
private int[] mColorTwo;
private int[] mColorThree;
public RadialGradientView(Context context) {
super(context);
}
public RadialGradientView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
public RadialGradientView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
{
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mColorThree = new int[]{
Color.parseColor("#ff0000"),
Color.parseColor("#00ff00"),
Color.parseColor("#0000ff")};
mColorTwo = new int[]{Color.parseColor("#ff0000"),
Color.parseColor("#0000ff")};
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//第一排 两色
mShader = new RadialGradient(200, 200, 40, mColorTwo[0], mColorTwo[1], Shader.TileMode.REPEAT);
mPaint.setShader(mShader);
canvas.drawCircle(200, 200, 150, mPaint);
mShader = new RadialGradient(500, 200, 40, mColorTwo[0], mColorTwo[1], Shader.TileMode.CLAMP);
mPaint.setShader(mShader);
canvas.drawCircle(500, 200, 150, mPaint);
mShader = new RadialGradient(800, 200, 40, mColorTwo[0], mColorTwo[1], Shader.TileMode.MIRROR);
mPaint.setShader(mShader);
canvas.drawCircle(800, 200, 150, mPaint);
//第二排 三色
mShader = new RadialGradient(200, 500, 40,
mColorThree,new float[]{0.0f,0.5f,1.0f},Shader.TileMode.REPEAT);
mPaint.setShader(mShader);
canvas.drawCircle(200, 500, 150, mPaint);
mShader = new RadialGradient(500, 500, 40,
mColorThree,new float[]{0.0f,0.5f,1.0f},Shader.TileMode.CLAMP);
mPaint.setShader(mShader);
canvas.drawCircle(500, 500, 150, mPaint);
mShader = new RadialGradient(800, 500, 40,
mColorThree,new float[]{0.0f,0.5f,1.0f},Shader.TileMode.MIRROR);
mPaint.setShader(mShader);
canvas.drawCircle(800, 500, 150, mPaint);
//第三排 三色改变渲染色起点位置
mShader = new RadialGradient(200, 800, 40,
mColorThree,new float[]{0.5f,0.75f,1.0f},Shader.TileMode.REPEAT);
mPaint.setShader(mShader);
canvas.drawCircle(200, 800, 150, mPaint);
mShader = new RadialGradient(500, 800, 40,
mColorThree,new float[]{0.5f,0.75f,1.0f},Shader.TileMode.CLAMP);
mPaint.setShader(mShader);
canvas.drawCircle(500, 800, 150, mPaint);
mShader = new RadialGradient(800, 800, 40,
mColorThree,new float[]{0.5f,0.75f,1.0f},Shader.TileMode.MIRROR);
mPaint.setShader(mShader);
canvas.drawCircle(800, 800, 150, mPaint);
//第四排 三色改变，修改渲染座标
mShader = new RadialGradient(50, 1100, 40,
mColorThree,new float[]{0.0f,0.5f,1.0f},Shader.TileMode.MIRROR);
mPaint.setShader(mShader);
canvas.drawCircle(200, 1100, 150, mPaint);
mShader = new RadialGradient(500, 950, 40,
mColorThree,new float[]{0.0f,0.5f,1.0f},Shader.TileMode.MIRROR);
mPaint.setShader(mShader);
canvas.drawCircle(500, 1100, 150, mPaint);
mShader = new RadialGradient(950, 1100, 40,
mColorThree,new float[]{0.0f,0.5f,1.0f},Shader.TileMode.MIRROR);
mPaint.setShader(mShader);
canvas.drawCircle(800, 1100, 150, mPaint);
}
}
布局文件
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.xol.widget.RadialGradientView
android:layout_width="match_parent"
android:layout_height="match_parent" />
</FrameLayout>
波纹点击效果
package com.xol.widget;
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ObjectAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RadialGradient;
import android.graphics.Shader;
import android.support.v7.widget.AppCompatButton;
import android.util.AttributeSet;
import android.view.MotionEvent;
/**
* Created by wwzhang on 2019/3/24
*/
public class RippleButtonView extends AppCompatButton {
private Paint mPaint;
private static final int DEFAULT_RADIUS = 50;
private int mDuration = 500;
private int radius;
private int mColorTwo[];
private Shader mShader;
private int mCenterX, mCenterY;
private ObjectAnimator mObjectAnimator;
public RippleButtonView(Context context) {
super(context);
}
public RippleButtonView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public RippleButtonView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
{
mCenterX = -1;
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mColorTwo = new int[]{Color.parseColor("#0000ff00")
, Color.parseColor("#ff00ff00")};
}
public void setRadius(int radius) {
this.radius = radius;
mShader = new RadialGradient(mCenterX, mCenterY, this.radius + 1, mColorTwo[0],
mColorTwo[1], Shader.TileMode.CLAMP);
mPaint.setShader(mShader);
invalidate();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mObjectAnimator == null) {
mObjectAnimator = ObjectAnimator.ofInt(this, "radius",
DEFAULT_RADIUS, getMeasuredWidth());
mObjectAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
setRadius(0);
}
});
mObjectAnimator.setDuration(mDuration);
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (mCenterX != (int) event.getX()) {
mCenterX = (int) event.getX();
mCenterY = (int) event.getY();
setRadius(DEFAULT_RADIUS);
}
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
return true;
case MotionEvent.ACTION_UP:
if (mObjectAnimator.isStarted()) {
mObjectAnimator.cancel();
} else {
mObjectAnimator.start();
}
break;
}
return super.onTouchEvent(event);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (mShader != null) {
canvas.drawCircle(mCenterX, mCenterY,
radius, mPaint);
}
}
}
布局文件
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.xol.widget.RippleButtonView
android:layout_gravity="center"
android:layout_width="match_parent"
android:layout_height="200dp" />
</FrameLayout>
运行效果
希望对您有所帮助！