android ShapeDrawable实例
? 今天看了一下api中的画图，遇到了一个新的类，Shader类介绍，android中提供了Shader类专门来渲染图像已经一些几何图形，shader 下面包括几个直接子类，分别是BitmapShaper，ComposeShader，LinerGradient,RadialGradient,SweepGradient.BitmapShader主要用来渲染图像，Shader类的使用，先构造Shdaer对象，然后通过Paint的setShader方法来设置渲染对象，然后再绘制使用这个Paint对象既可。
import android.app.Activity;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapShader;import android.graphics.Canvas;import android.graphics.ComposePathEffect;import android.graphics.CornerPathEffect;import android.graphics.DiscretePathEffect;import android.graphics.LinearGradient;import android.graphics.Paint;import android.graphics.Path;import android.graphics.PathEffect;import android.graphics.RectF;import android.graphics.Shader;import android.graphics.SweepGradient;import android.graphics.drawable.Drawable;import android.graphics.drawable.ShapeDrawable;import android.graphics.drawable.shapes.ArcShape;import android.graphics.drawable.shapes.OvalShape;import android.graphics.drawable.shapes.PathShape;import android.graphics.drawable.shapes.RectShape;import android.graphics.drawable.shapes.RoundRectShape;import android.graphics.drawable.shapes.Shape;import android.os.Bundle;import android.view.View;public class ShapeDrawble1 extends Activity { /** Called when the activity is first created. */ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(new SampleView(this)); } private static class SampleView extends View { private ShapeDrawable[] mDrawables; private static Shader makeSweep() { /* SweepGradient 是继承于Shader的，它是以中心点（150，25） * 按照下列四种颜色进行变化的*/ return new SweepGradient(0, 0, new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF, 0xFFFF0000 }, null);// null 表示均衡变化 } private static Shader makeLinear() { //颜色按照直线线性变化的着色器 return new LinearGradient(100, 100, 0, 0, new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF }, null, Shader.TileMode.MIRROR); } private static Shader makeTiling() { int[] pixels = new int[] { 0xFFFF0000, 0xFF00FF00, 0xFF0000FF, 0}; Bitmap bm = Bitmap.createBitmap(pixels, 1, 1, Bitmap.Config.ARGB_8888); /** * BitmapShader 是一个位图着色器，这个着色器是通过 * 在x，y方向重复位图bm的像素来着色的 * */ return new BitmapShader(bm, Shader.TileMode.REPEAT, Shader.TileMode.REPEAT); } /** * ShapeDrawable 是绘制各种几何体的类。它注入想要绘制的形状shap * 类，就可以绘制出我们想要的集合体，这个类最寒心的就是draw（canvas） * 和onDraw（Shape，Canvas，Paint）这个方法调用 * */ private static class MyShapeDrawable extends ShapeDrawable { //Paint.ANTI_ALIAS_FLAG代表这个画笔的图形是光滑的 private Paint mStrokePaint = new Paint(Paint.ANTI_ALIAS_FLAG); public MyShapeDrawable(Shape s) { super(s); mStrokePaint.setStyle(Paint.Style.STROKE); } public Paint getStrokePaint() { return mStrokePaint; } @Override protected void onDraw(Shape s, Canvas c, Paint p) { //绘制填充效果的图形 s.draw(c, p); //绘制黑边 s.draw(c, mStrokePaint); } } public SampleView(Context context) { super(context); setFocusable(true); //外部圆角矩形的圆角圆半径，上面俩个角是圆 float[] outerR = new float[] { 12, 12, 12, 12, 0, 0, 0, 0 }; //内部矩形 RectF inset = new RectF(6, 6, 6, 6); //内部圆角矩形的圆角是圆半径，左上角和右下角是圆角矩形 float[] innerR = new float[] { 12, 12, 0, 0, 12, 12, 0, 0 }; //绘制一个顶点为下列四个点的棱形 Path path = new Path(); path.moveTo(50, 0); path.lineTo(0, 50); path.lineTo(50, 100); path.lineTo(100, 50); //封闭前面点所绘制的路径 path.close(); mDrawables = new ShapeDrawable[7]; //绘制矩形 mDrawables[0] = new ShapeDrawable(new RectShape()); //绘制椭圆 mDrawables[1] = new ShapeDrawable(new OvalShape()); //绘制上面俩个角是圆角的矩形 mDrawables[2] = new ShapeDrawable(new RoundRectShape(outerR, null, null)); //绘制上面俩角是圆角，并且有一个内嵌的矩形 mDrawables[3] = new ShapeDrawable(new RoundRectShape(outerR, inset, null)); ////绘制上面俩角是圆角，并且有一个内嵌的矩形且左上角和右下角是圆形矩形环 mDrawables[4] = new ShapeDrawable(new RoundRectShape(outerR, inset, innerR)); //绘制指定路径的集合体 mDrawables[5] = new ShapeDrawable(new PathShape(path, 100, 100)); // 用自定的ShapDrawble绘制开始弧度45扫过弧度-270的椭圆 mDrawables[6] = new MyShapeDrawable(new ArcShape(45, -270)); mDrawables[0].getPaint().setColor(0xFFFF0000); mDrawables[1].getPaint().setColor(0xFF00FF00); mDrawables[2].getPaint().setColor(0xFF0000FF); mDrawables[3].getPaint().setShader(makeSweep()); mDrawables[4].getPaint().setShader(makeLinear()); mDrawables[5].getPaint().setShader(makeTiling()); mDrawables[6].getPaint().setColor(0x88FF8844); //DiscretePathEffect是一个折线路径效果，分割长度是10，偏差时4 PathEffect pe = new DiscretePathEffect(10, 4); //CornerPathEffect是将2个路径效果合并后的路径效果 PathEffect pe2 = new CornerPathEffect(4); mDrawables[3].getPaint().setPathEffect( new ComposePathEffect(pe2, pe)); MyShapeDrawable msd = (MyShapeDrawable)mDrawables[6]; //设置笔画宽度等于4 msd.getStrokePaint().setStrokeWidth(4); } @Override protected void onDraw(Canvas canvas) { int x = 10; int y = 10; int width = 300; int height = 50; //循环绘制 for (Drawable dr : mDrawables) { dr.setBounds(x, y, x + width, y + height); dr.draw(canvas); y += height + 5; } } }}?
1 楼 dengrui0917 2011-11-22 最近我也要做一个将图片压缩成气泡状的图片，下载研究一下