Android(安卓)颜色渲染(五) LinearGradient线性渲染

Android 颜色处理(五) LinearGradient线性渲染

相信很多人都看过歌词同步的效果, 一是竖直方向的滚动，另一方面是水平方面的歌词颜色渐变点亮效果,这种效果怎么做呢? 这就需要用到LinearGradient线性渲染,下面还是先看具体的使用:

LinearGradient有两个构造函数;

public LinearGradient(float x0, float y0, float x1, float y1, int[] colors, float[] positions,Shader.TileMode tile)

参数:

float x0: 渐变起始点x坐标

float y0:渐变起始点y坐标

float x1:渐变结束点x坐标

float y1:渐变结束点y坐标

int[] colors:颜色的int 数组

float[] positions: 相对位置的颜色数组,可为null, 若为null,可为null,颜色沿渐变线均匀分布

Shader.TileMode tile: 渲染器平铺模式

public LinearGradient(float x0, float y0, float x1, float y1, int color0, int color1,Shader.TileMode tile)

float x0: 渐变起始点x坐标

float y0:渐变起始点y坐标

float x1:渐变结束点x坐标

float y1:渐变结束点y坐标

int color0: 起始渐变色

int color1: 结束渐变色

Shader.TileMode tile: 渲染器平铺模式

效果图:

然后看一下具体怎么实现这种效果;

MainActivity:

package com.tony.shader;import android.os.Bundle;import android.app.Activity;public class MainActivity extends Activity {private LinearGradientView linearGradientView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);linearGradientView = new LinearGradientView(this);setContentView(linearGradientView);}}

LinearGradientView;

package com.tony.shader;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.LinearGradient;import android.graphics.Paint;import android.util.AttributeSet;import android.graphics.Shader;import android.view.View;public class LinearGradientView extends View {private LinearGradient linearGradient = null;      private Paint paint = null;      public LinearGradientView(Context context)      {          super(context);          linearGradient = new LinearGradient(0, 0, 100, 100, new int[] {                  Color.YELLOW, Color.GREEN, Color.TRANSPARENT, Color.WHITE }, null,                  Shader.TileMode.REPEAT);          paint = new Paint();      }      public LinearGradientView(Context context, AttributeSet attrs) {super(context, attrs);}@Overrideprotected void onDraw(Canvas canvas) {// TODO Auto-generated method stubsuper.onDraw(canvas);//设置渲染器paint.setShader(linearGradient);                  //绘制圆环canvas.drawCircle(240, 360, 200, paint); }}

public LinearGradient(float x0, float y0, float x1, float y1, int color0, int color1,Shader.TileMode tile)

更多相关文章

随机推荐