先上图

其实以上效果没有让美工提供任何图片 只要学会Shape你就能实现 想怎么样就怎么样

下面介绍Shape的用法：

<shape>  android:shape=["rectangle" | "oval" | "line" | "ring"]

其中rectagle矩形，oval椭圆，line水平直线，ring环形

<shape>中子节点的常用属性：

<gradient>  渐变

android:startColor  起始颜色

android:endColor  结束颜色

android:angle  渐变角度，0从上到下，90表示从左到右，数值为45的整数倍默认为0；

android:type  渐变的样式 liner线性渐变 radial环形渐变 sweep

<solid >  填充

android:color  填充的颜色

<stroke > 描边

android:width 描边的宽度

android:color 描边的颜色

android:dashWidth 表示'-'横线的宽度

android:dashGap 表示'-'横线之间的距离

<corners > 圆角

android:radius  圆角的半径 值越大角越圆

android:topRightRadius  右上圆角半径
 
android:bottomLeftRadius 右下圆角角半径
 
android:topLeftRadius 左上圆角半径

android:bottomRightRadius 左下圆角半径

2.用selector添加shape
<?xml version="1.0" encoding="utf-8"?>
    <selector xmlns:android="http://schemas.android.com/apk/res/android">

    
        <item android:state_selected="true">
            <shape>
                <gradient android:angle="270" android:endColor="#99BD4C"
                    android:startColor="#A5D245" />
                <size android:height="60dp" android:width="320dp" />
                <corners android:radius="8dp" />
            </shape>
        </item>
        <item android:state_pressed="true">
            <shape>
                <gradient android:angle="270" android:endColor="#99BD4C"
                    android:startColor="#A5D245"/>
                <size android:height="60dp" android:width="320dp" />
                <corners android:radius="8dp" />
            </shape>
        </item>
        <item>
            <shape>
                <gradient android:angle="270" android:endColor="#A8C3B0"
                    android:startColor="#C6CFCE"/>
                <size android:height="60dp" android:width="320dp" />
                <corners android:radius="8dp" />
            </shape>
        </item>
    </selector>

原创 2015年09月06日 10:12:59

前言

使用Shape 的oval 属性画圆环图形在api15及api16 上会变成黑圆形

如下图所示

xml 如下

解决办法

经过研究 发现 需要填充背景色为透明即可

如下图

xml 如下

Shape继承体系：

Shape (android.graphics.drawable.shapes)
----PathShape (android.graphics.drawable.shapes)
----RectShape (android.graphics.drawable.shapes)
--------ArcShape (android.graphics.drawable.shapes)
--------OvalShape (android.graphics.drawable.shapes)
--------RoundRectShape (android.graphics.drawable.shapes)

RectShape

RectShape rectShape = new RectShape();

ShapeDrawable drawable = new ShapeDrawable(rectShape);

drawable.getPaint().setColor(Color.RED);

drawable.getPaint().setStyle(Paint.Style.FILL); //填充

view.setBackgroundDrawable(drawable);

 矩形

RoundRectShape

float[] outerRadii = {20, 20, 40, 40, 60, 60, 80, 80};//外矩形 左上、右上、右下、左下 圆角半径

//float[] outerRadii = {20, 20, 20, 20, 20, 20, 20, 20};//外矩形 左上、右上、右下、左下 圆角半径

RectF inset = new RectF(100, 100, 200, 200);//内矩形距外矩形，左上角x,y距离， 右下角x,y距离

float[] innerRadii = {20, 20, 20, 20, 20, 20, 20, 20};//内矩形 圆角半径

//RoundRectShape roundRectShape = new RoundRectShape(outerRadii, inset, innerRadii);

RoundRectShape roundRectShape = new RoundRectShape(outerRadii, null, innerRadii); //无内矩形

ShapeDrawable drawable = new ShapeDrawable(roundRectShape);

drawable.getPaint().setColor(Color.MAGENTA);

drawable.getPaint().setAntiAlias(true);

drawable.getPaint().setStyle(Paint.Style.STROKE);//描边

view.setBackground(drawable);

 无内矩形的圆角矩形  带内矩形的圆角矩形

OvalShape

OvalShape ovalShape = new OvalShape();

ShapeDrawable drawable = new ShapeDrawable(ovalShape);

drawable.getPaint().setColor(Color.RED);

drawable.getPaint().setStyle(Paint.Style.FILL_AND_STROKE);

view.setBackgroundDrawable(drawable);

 椭圆。 而当View的宽高相等时，就绘出了圆

ArcShape

ArcShape arcShape = new ArcShape(45, 270); //顺时针  开始角度45， 扫描的角度270   扇形

ShapeDrawable drawable = new ShapeDrawable(arcShape);

drawable.getPaint().setColor(Color.RED);

drawable.getPaint().setStyle(Paint.Style.FILL);

// Bitmap bitmap =  ((BitmapDrawable)getResources().getDrawable(R.drawable.aa)).getBitmap();

// BitmapShader bitmapShader = new BitmapShader(bitmap, Shader.TileMode.MIRROR, Shader

//                .TileMode.REPEAT);

// Matrix matrix = new Matrix();

// matrix.preScale(600.00f / bitmap.getWidth(), 600.00f / bitmap.getHeight());//view:w=600,h=600

// bitmapShader.setLocalMatrix(matrix);

// drawable.getPaint().setShader(bitmapShader);

view.setBackgroundDrawable(drawable);

 扇形图

 结合BitmapShader

PathShape

Path path = new Path();

path.moveTo(50, 0);

path.lineTo(0, 50);

path.lineTo(50, 100);

path.lineTo(100, 50);

path.lineTo(50, 0);

PathShape pathShape = new PathShape(path, 200, 100);

ShapeDrawable drawable = new ShapeDrawable(pathShape);

drawable.getPaint().setColor(Color.RED);

drawable.getPaint().setStyle(Paint.Style.FILL);

imageView.setBackgroundDrawable(drawable);

以Path路径对象，来设定图形。

PathShape的构造函数：PathShape(path, stdWidth, stdHeight);

stdWidth：标准宽度

stdHeight：标准高度

在构造PathShape对象时，设置了宽高的标准。内部函数

protected void onResize(float width, float height) {

    mScaleX = width / mStdWidth;

    mScaleY = height / mStdHeight;

}

public void draw(Canvas canvas, Paint paint) {

    canvas.save();

    canvas.scale(mScaleX, mScaleY);

    canvas.drawPath(mPath, paint);

    canvas.restore();

}

Shape基类中有函数 resize()，其中调用了onResize()；ShapeDrawable中会调用resize()。

有了设定的标准宽高，再算出实际宽高与标准宽高的比率，最后在绘制时，画布canvas缩放。

造成的效果： path中的(x,y)坐标值 乘以 比率值，即是 最终呈现出的坐标值(实际内部是缩放的canvas)

比如，这里view的 w=400， h=400

如果标准宽高都等于400，那么canvas最终不缩放，即1:1。

PathShape pathShape = new PathShape(path, 400, 400);

  stdx=400, stdy=400

PathShape pathShape = new PathShape(path, 100, 100);

 stdx=100, stdy=100

PathShape pathShape = new PathShape(path, 200, 100);

 stdx=200, stdy=100

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