Paint介绍

Paint介绍

1. Paint.Cap

注意：Cap一般作用于边界处，不作用连接处

BUTT (0),//无线帽

ROUND (1),//圆形线帽

SQUARE (2);//方形线帽

![Cap图片]!

paint.setColor(Color.RED);
paint.setStrokeWidth(60);
paint.setStrokeCap(Paint.Cap.BUTT);
canvas.drawLine(100, 100, 600, 100, paint);

paint.setStrokeCap(Paint.Cap.ROUND);
canvas.drawLine(100, 300, 600, 300, paint);

paint.setStrokeCap(Paint.Cap.SQUARE);
canvas.drawLine(100, 500, 600, 500, paint);

2. Paint.Join

MITER   (0),//有尖角的连接
ROUND   (1),//圆弧连接
BEVEL   (2);//直线连接

paint.setStrokeWidth(60);
paint.setColor(Color.YELLOW);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.MITER);
canvas.drawRect(new RectF(100,100,300,300),paint);
paint.setStrokeJoin(Paint.Join.BEVEL);
canvas.drawRect(400, 100, 600, 300, paint);
paint.setStrokeJoin(Paint.Join.ROUND);
canvas.drawRect(100, 400, 300, 600, paint);

3. Paint.Align

paint.setStrokeWidth(5);
paint.setTextSize(30);
paint.setShadowLayer(10,10,10,Color.RED);
paint.setTextAlign(Paint.Align.LEFT);
canvas.drawText("Paint.Align.LEFT",400,100,paint);
paint.setShadowLayer(10,10,10,Color.RED);
paint.setTextAlign(Paint.Align.CENTER);
canvas.drawText("Paint.Align.CENTER",400,300,paint);
paint.setShadowLayer(10,10,10,Color.RED);
paint.setTextAlign(Paint.Align.RIGHT);
canvas.drawText("Paint.Align.RIGHT",400,500,paint);
canvas.drawLine(400,0,400,800,paint);

4. Paint.Style

Paint.Style.FILL：填充内部

Paint.Style.STROKE 描边

Paint.Style.FILL_AND_STROKE ：填充内部和描边

paint.setStrokeWidth(20);
paint.setStyle(Paint.Style.FILL);
canvas.drawRect(new RectF(100,100,300,300),paint);
canvas.drawText("Paint.Style.FILL",350,200,paint);
paint.setStyle(Paint.Style.STROKE);
canvas.drawRect(new RectF(100,350,300,550),paint);
canvas.drawText("Paint.Style.STROKE",350,400,paint);
paint.setStyle(Paint.Style.FILL_AND_STROKE);
canvas.drawRect(new RectF(100,600,300,800),paint);

canvas.drawRect(new RectF(100,350,300,550),paint);
canvas.drawText("Paint.Style.FILL_AND_STROKE",350,700,paint);

5.Paint.FontMetrics



ascent = ascent线的y坐标 - baseline线的y坐标；//负数

descent = descent线的y坐标 - baseline线的y坐标；//正数

top = top线的y坐标 - baseline线的y坐标；//负数

bottom = bottom线的y坐标 - baseline线的y坐标；//正数

leading = top线的y坐标 - ascent线的y坐标；//负数

paint.setStrokeWidth(1);
paint.setTextSize(50);
Paint.FontMetrics fontMetrics = paint.getFontMetrics();
float ascent = fontMetrics.ascent +300;
float descent = fontMetrics.descent+300;
float top = fontMetrics.top + 300;
float bottom = fontMetrics.bottom + 300;
canvas.drawText("abcdefg",300,300,paint);
paint.setTextSize(20);
canvas.drawLine(300,ascent,600,ascent,paint);
canvas.drawText("ascent=top",650,ascent,paint);
canvas.drawLine(300,descent,600,descent,paint);
canvas.drawText("descent=bottom",650,descent,paint);
canvas.drawLine(300,-(bottom-top)/2+bottom,600,-(bottom-top)/2+bottom,paint);//中线
canvas.drawText("center",650,-(bottom-top)/2+bottom,paint);

6. Paint方法介绍

reset() //重置Paint。

setFlags(int flags)//设置一些标志，比如抗锯齿，下划线等等。

setDither(boolean dither)//设置是否抖动，如果不设置感觉就会有一些僵硬的线条，如果设置图像就会看的更柔和一些

setLinearText(boolean linearText) //这个是文本缓存，设置线性文本，如果设置为true就不需要缓存

setSubpixelText(boolean subpixelText)//设置亚像素，是对文本的一种优化设置，可以让文字看起来更加清晰明显

setUnderlineText(boolean underlineText)//设置文本的下划线

setStrikeThruText(boolean strikeThruText)//设置文本的删除线

setFakeBoldText(boolean fakeBoldText)//设置文本粗体

setFilterBitmap(boolean filter)//对位图进行滤波处理，如果该项设置为true，则图像在动画进行中会滤掉对Bitmap图像的优化操作，加快显示

setStrokeMiter(float miter)//当style为Stroke或StrokeAndFill时设置连接处的倾斜度，这个值必须大于1,锐角越接近0，miter值得上限越大，也就是<=MITERmax时都有倾斜

paint.setStrokeWidth(30);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeMiter((float)3);
Path path = new Path();
path.moveTo(0,30);
path.lineTo(400,250);
path.lineTo(300,30);

canvas.drawPath(path,paint);
path.reset();
paint.setStrokeMiter((float)2);
path.moveTo(300,300);
path.lineTo(500,300);
path.lineTo(400,550);
canvas.drawPath(path,paint);

setShader(Shader shader)//设置着色器，用来给图像着色的，绘制出各种渐变效果，有BitmapShader，ComposeShader，LinearGradient，RadialGradient，SweepGradient几种

BitmapShader

构造方法：BitmapShader (Bitmap bitmap, Shader.TileMode tileX, Shader.TileMode tileY)

第一个参数：要处理的bitmap对象

第二个参数：在X轴处理的效果，Shader.TileMode里有三种模式：CLAMP、MIRROR和REPETA

第三个参数：在Y轴处理的效果，Shader.TileMode里有三种模式：CLAMP、MIRROR和REPETA

Shader.TileMode.CLAMP会将边缘的一个像素进行拉伸、扩展



拉伸后效果



Shader.TileMode.MIRROR模式作用是镜像



Shader.TileMode.REPEAT

这个应该是重复模式，和镜像十分类似，但是不是翻转复制，而是平移复制。(x轴方向平移复制，y轴方向镜像复制)



LinearGradient

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

（x0，y0）表示渐变的起点坐标而（x1，y1）则表示渐变的终点坐标，这两点都是相对于屏幕坐标系而言的，而color0和color1则表示起点的颜色和终点的颜色，TileMode和上面讲的完全一致。

[（x0,y0,x1,y1)范围为三角形(x0,y0)(2x1-x0,y0)(x0,2y1-y0)自己想的）]

paint.setShader(new LinearGradient(0,0,100,100,Color.RED,Color.YELLOW, Shader.TileMode.MIRROR));
canvas.drawRect(new RectF(0,0,400,400),paint);

另一个构造方法：public LinearGradient (float x0, float y0, float x1, float y1, int[] colors, float[] positions, Shader.TileMode tile)

colors和positions都是数组,positions可以为空，为空时系统自动调整，颜色变化是线性的，在pos[i+1]-pos[i]位置线性到达color[i+1]

paint.setShader(new LinearGradient(0,0,200,200,new int[]{Color.RED,Color.BLUE,Color.YELLOW},
new float[]{0F,0.4F,1F}, Shader.TileMode.REPEAT));
canvas.drawRect(new RectF(0,0,400,400),paint);

绘制图片阴影

canvas.drawColor(Color.GRAY);
int x = 200, y = 200;
// 获取源图
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.apic);
// 实例化一个矩阵对象
Matrix matrix = new Matrix();
matrix.setScale(1F,-1F);//第一个参数表示x缩放,第二参数表示y的缩放
Bitmap refBitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
// 绘制好原图
canvas.drawBitmap(bitmap, x, y, null);
// 保存图层。ALL_SAVE_FLAG保存所有信息，包括裁剪区域和矩阵变化，restore()返回最上一层
int sc = canvas.saveLayer(x, y + bitmap.getHeight(), x + bitmap.getWidth(), y + bitmap.getHeight() * 2, null, Canvas.ALL_SAVE_FLAG);
// 绘制倒影图片，绘制的区域紧贴原图的底部
canvas.drawBitmap(refBitmap, x, y + bitmap.getHeight(),null);
// 设置好混合模式
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));//显示src和des重叠的src部分
paint.setShader(new LinearGradient(x, y + bitmap.getHeight(),x, y + bitmap.getHeight() +
bitmap.getHeight() / 4,Color.BLACK, Color.TRANSPARENT, Shader.TileMode.CLAMP));
// 画一个矩形区域，作为目标图片，用来做混合模式
canvas.drawRect(x, y + bitmap.getHeight(), x + refBitmap.getWidth(), y + bitmap.getHeight() * 2, paint);
paint.reset();
canvas.restoreToCount(sc);//restoreToCount()返回到sc层，类似于堆栈一个一个取出来

为了看清效果，我把倒影图和原图大小变得不一样，倒影图比原图小20px;



SweepGradient

它的意思是梯度渐变，也称之为扫描式渐变，因为其效果有点类似雷达的扫描效果

构造方法:SweepGradient(float cx, float cy, int color0, int color1)

paint.setShader(new SweepGradient(100,100,Color.RED,Color.YELLOW));
canvas.drawRect(new RectF(0,0,200,200),paint);

效果：



构造方法：

SweepGradient(float cx, float cy, int[] colors, float[] positions)

paint.setShader(new SweepGradient(100,100,new int[]{Color.RED,Color.BLUE,Color.TRANSPARENT},new float[]{0F,0.4F,1.0F}));//Color.RED->Color.BLUE是从0->0.4,position是相对这个区域的，postion可以为null
canvas.drawRect(new RectF(0,0,200,200),paint);

效果：



RadialGradient

径向渐变，径向渐变说的简单点就是个圆形中心向四周渐变的效果

构造方法：

RadialGradient (float centerX, float centerY, float radius, int centerColor, int edgeColor, Shader.TileMode tileMode)

RadialGradient (float centerX, float centerY, float radius, int[] colors, float[] stops, Shader.TileMode tileMode)

paint.setShader(new RadialGradient(100,100,100,Color.RED,Color.BLUE, Shader.TileMode.CLAMP));
canvas.drawRect(new RectF(0,0,200,200),paint);

效果：

paint.setShader(new RadialGradient(100,100,100,new int[]{Color.RED,Color.BLUE,Color.YELLOW}, new float[]{0,0.5f,1.0f},Shader.TileMode.CLAMP));
canvas.drawRect(new RectF(0,0,200,200),paint);

效果：



ComposeShader

构造方法：ComposeShader (Shader shaderA, Shader shaderB, Xfermode mode)

ComposeShader (Shader shaderA, Shader shaderB, PorterDuff.Mode mode)

一般是一个BitmapShader+一个XXGradient;

Shader shader = new BitmapShader(BitmapFactory.decodeResource(getResources(),R.drawable.apic), Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
Shader shader01 = new SweepGradient(200,200,new int[]{Color.YELLOW,Color.RED,Color.BLUE},new float[]{0.25f,0.5f,0.75f});
paint.setShader(new ComposeShader(shader01, shader, PorterDuff.Mode.MULTIPLY));
canvas.drawRect(0, 0, 400, 400, paint);

效果：


Shader And Matrix

Shader shader = new BitmapShader(BitmapFactory.decodeResource(getResources(),R.drawable.apic), Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
Matrix matrix = new Matrix();
matrix.setTranslate(100,100);
shader.setLocalMatrix(matrix);
paint.setShader(shader);
canvas.drawRect(0, 0, 400, 400, paint);

效果：

Shader shader = new BitmapShader(BitmapFactory.decodeResource(getResources(),R.drawable.apic), Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
Matrix matrix = new Matrix();
matrix.postTranslate(200,100);
matrix.preRotate(45);
shader.setLocalMatrix(matrix);
paint.setShader(shader);
canvas.drawRect(0, 0, 400, 400, paint);

效果：



setColorFilter(ColorFilter filter)//设置画笔颜色过滤器，有ColorMatrixColorFilter，LightingColorFilter，PorterDuffColorFilter几种

先介绍ColorMatrix:

颜色矩阵的计算：



ColorMatrix函数介绍：

色调调节setRotate(int axis, float degrees)







效果叠加

preConcat(ColorMatrix prematrix)和postConcat(ColorMatrix postmatrix)两个方法分别是将目标效果矩阵放在本矩阵之前和放在本矩阵之后，由于矩阵的乘法一般不满足交换律，因此前后关系会对效果有不同的影响。

ColorMatrixColorFilter

reset();
Bitmap bitmap = BitmapFactory.decodeResource(getResources(),R.drawable.apic);
canvas.drawBitmap(bitmap,100,0,paint);
paint.setColorFilter(new ColorMatrixColorFilter(a));
canvas.drawBitmap(bitmap,100,500,paint);
ColorMatrix colorMatrix = new ColorMatrix();
colorMatrix.setSaturation(0);
paint.setColorFilter(new ColorMatrixColorFilter(colorMatrix));
canvas.drawBitmap(bitmap,100,1000,paint);

LightingColorFilter

Bitmap bitmap = BitmapFactory.decodeResource(getResources(),R.drawable.apic);
canvas.drawBitmap(bitmap,100,0,paint);
paint.setColorFilter(new LightingColorFilter(0x888888,0x000000));
canvas.drawBitmap(bitmap,100,500,paint);
paint.setColorFilter(new LightingColorFilter(0x888888,0x555555));
canvas.drawBitmap(bitmap,100,1000,paint);

PorterDuffColorFilter

构造方法：public PorterDuffColorFilter(int srcColor, PorterDuff.Mode mode)

Bitmap bitmap = BitmapFactory.decodeResource(getResources(),R.drawable.apic);
paint.setColorFilter(new PorterDuffColorFilter(Color.RED, PorterDuff.Mode.MULTIPLY));
canvas.drawBitmap(bitmap,100,0,paint);

PorterDuff.Mode种类



setPathEffect(PathEffect effect)//设置绘制路径的效果，有ComposePathEffect，CornerPathEffect，DashPathEffect，DiscretePathEffect，PathDashPathEffect，SumPathEffect几种

CornerPathEffect：

构造函数：CornerPathEffect(float radius）

参数radius代表了半径，这里的半径就是塞进拐角处圆形的半径，即是用多大半径的圆弧来替换这个拐角。

Path path = new Path();
path.moveTo(100,400);
path.rLineTo(400,400);
path.rLineTo(100,-400);
paint.setStyle(Paint.Style.STROKE);
paint.setColor(Color.BLUE);
paint.setPathEffect(new CornerPathEffect(100));
canvas.drawPath(path,paint);

DashPathEffect

构造函数：DashPathEffect(float intervals[], float phase)

其中intervals是间隔，他是一个数组，其中数值必须为偶数，2个为一对，必须成对出现，一对中的第一个代表了线段长度(为0则绘制)，第二个代表了空白长度（为0则不留空白）这里可以看出来其实线段2中是由两对数值组成的值如下：

float[] intervals = {100,20,200,50};

参数中phase（假设是80）代表了相位表示从intervals 80开始，也就是先绘制100-80=20的实线，然后绘制20空白，让后绘制200实线，然后绘制50空白，接着绘制100实线，以此类推

float intervals[] = {100,30,200,50};
paint.setStyle(Paint.Style.STROKE);
paint.setColor(Color.BLUE);
paint.setPathEffect(new DashPathEffect(intervals,0));
Path path = new Path();
path.moveTo(100,500);
path.rLineTo(500,500);
path.rLineTo(100,-500);
canvas.drawPath(path,paint);
path.reset();
path.moveTo(100,900);
path.rLineTo(500,500);
path.rLineTo(500,-500);
canvas.drawPath(path,paint);

DiscretePathEffect

构造函数： DiscretePathEffect(float segmentLength, float deviation)

这里有两个参数，第一个segmentLength字面上看就是段长，deviation代表偏差值。

参数一：指定了原始线段被切分成多长的线段，比如原始线段长度为100.段长设置为20，那么就被切成了5段。

参数二：指定了切割后的小线段于原始位置的偏离距离。

paint.setStyle(Paint.Style.STROKE);
paint.setColor(Color.BLUE);
paint.setPathEffect(new DiscretePathEffect(10,10));
Path path = new Path();
path.moveTo(100,500);
path.rLineTo(500,500);
path.rLineTo(100,-500);
canvas.drawPath(path,paint);
paint.setPathEffect(new DiscretePathEffect(10,20));
path.reset();
path.moveTo(100,900);
path.rLineTo(500,500);
path.rLineTo(500,-500);
canvas.drawPath(path,paint);

PathDashPathEffect

PathDashPathEffect(Path shape, float advance, float phase,Style style)

shape：代表了绘制的形状，这里是一个三角形

advace：绘制位移，上一次绘制这个三角形，和下一次绘制三角形起点之间的位移

phase：相位，于之前讲解的相同

style：风格，这里后面三条线就是因为这个参数引起的不同

Style是一个枚举，值如下

TRANSLATE(0), //平移

ROTATE(1), //旋转

MORPH(2); //变形

Path pathDash = new Path();
pathDash.rLineTo(10,10);
pathDash.rLineTo(10,-10);
pathDash.close();
paint.setStyle(Paint.Style.STROKE);
paint.setColor(Color.BLUE);
paint.setPathEffect(new PathDashPathEffect(pathDash,35,0, PathDashPathEffect.Style.TRANSLATE));
Path path = new Path();
path.moveTo(100,500);
path.rLineTo(500,500);
path.rLineTo(100,-500);
canvas.drawPath(path,paint);
paint.setPathEffect(new PathDashPathEffect(pathDash,35,0, PathDashPathEffect.Style.ROTATE));
path.reset();
path.moveTo(100,900);
path.rLineTo(500,500);
path.rLineTo(500,-500);
canvas.drawPath(path,paint);

ComposePathEffect和SumPathEffect

float intervals[] = {100,30};
paint.setStyle(Paint.Style.STROKE);
paint.setColor(Color.BLUE);
paint.setPathEffect(new ComposePathEffect(new DashPathEffect(intervals,0),new CornerPathEffect(100)));
Path path = new Path();
path.moveTo(100,500);
path.rLineTo(500,500);
path.rLineTo(100,-500);
canvas.drawPath(path,paint);
paint.setPathEffect(new SumPathEffect(new DashPathEffect(intervals,0),new CornerPathEffect(100)));
path.reset();
path.moveTo(100,900);
path.rLineTo(500,500);
path.rLineTo(500,-500);
canvas.drawPath(path,paint);

线段1是compose，线段2是sum，看图就已经非常明显，sum只是简单的叠加效果，而compose是组合效果。



setMaskFilter(MaskFilter maskfilter)//对图像进行一定的处理，实现滤镜的效果，如滤化，立体等,有BlurMaskFilter，EmbossMaskFilter几种

BlurMaskFilter：

构造函数：BlurMaskFilter(float radius, BlurMaskFilter.Blur style)

第一个参数：radius很容易理解，值越大我们的阴影越扩散，用过PS的人会很容易理解，其实就是阴影范围。

第二个参数：style表示的是模糊的类型，有SOLID，NORMAL,OUTER和INNER

setLayerType(LAYER_TYPE_SOFTWARE, null);//关闭硬件加速
paint.setColor(Color.BLUE);
paint.setMaskFilter(new BlurMaskFilter(30, BlurMaskFilter.Blur.SOLID));
canvas.drawRect(new RectF(100,100,500,500),paint);
paint.setMaskFilter(new BlurMaskFilter(30, BlurMaskFilter.Blur.NORMAL));
canvas.drawRect(new RectF(100,600,500,1000),paint);
paint.setMaskFilter(new BlurMaskFilter(30, BlurMaskFilter.Blur.OUTER));
canvas.drawRect(new RectF(600,100,1000,500),paint);
paint.setMaskFilter(new BlurMaskFilter(30, BlurMaskFilter.Blur.INNER));
canvas.drawRect(new RectF(600,600,1000,1000),paint);