近期用了一下View上绘画，在总结一下：
其实都是直接使用sdk中提供的接口
绘制图形的例子
package com.cby.jason.draw2d;import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;/*** Created by Jason on 2016/2/27.*/
public class DrawGraphicalView extends View{private Paint paint1 = new Paint();private Paint paint2 = new Paint();public DrawGraphicalView(Context context) {super(context);initView();}public DrawGraphicalView(Context context, AttributeSet attrs) {super(context, attrs);initView();}private void initView() {//初始化paint1.setColor(Color.RED);paint1.setStrokeWidth(10f);paint2.setColor(Color.YELLOW);paint2.setStrokeWidth(20f);paint2.setStyle(Paint.Style.STROKE);}@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);//画像素点canvas.drawPoint(100,80,paint1);canvas.drawPoint(100, 100, paint2);canvas.drawPoints(new float[]{100, 120, 100, 140}, paint1);//画线canvas.drawLine(10,10,200,10,paint1);canvas.drawLine(10, 40, 200, 40, paint2);//用线画三角形canvas.drawLines(new float[]{160, 100, 80, 250, 160, 100, 240, 250, 80, 250, 240, 250}, paint1);//画矩形canvas.drawRect(80,300,380,600,paint1);canvas.drawRect(40,260,440,640,paint2);Rect r = new Rect(100,320,360,580);Paint p = new Paint();p.setStrokeWidth(10f);p.setStyle(Paint.Style.STROKE);p.setColor(Color.BLUE);canvas.drawRect(r, p);//画弧canvas.drawArc(480, 300, 880, 600, 15f, 220f, false, paint1);canvas.drawArc(40, 660, 440, 1040, 30, 150, true, paint2);RectF r1 = new RectF(480, 660, 880, 1040);canvas.drawArc(r1, 15f, 220f, true, paint1);//画圆canvas.drawCircle(600, 120, 100f, paint1);//画椭圆canvas.drawArc(450, 20, 750, 220, 0, 360, false, paint2);//画文字canvas.drawText("what are words",66,1200,new Paint(Color.BLACK));canvas.drawText("what are words",3,9,66,1250,new Paint(Color.BLACK));Paint p1 = new Paint(Color.BLACK);p1.setTextSize(25);//设置文字大小canvas.drawText("what are words",66,1300,p1);//canvas.drawOval(150,1300,300,1450,p1);}
}
package com.cby.jason.draw2d;import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.PixelFormat;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.View;import java.io.InputStream;/*** Created by Jason on 2016/2/28.*/
public class DrawBitmapView extends View {private Bitmap mBitmap;private Bitmap bm;private InputStream is;private Context mContext;public DrawBitmapView(Context context) {super(context);initView(context);}public DrawBitmapView(Context context, AttributeSet attrs) {super(context, attrs);initView(context);}private void initView(Context context){mContext = context;is = context.getResources().openRawResource(R.raw.ic_folders);BitmapFactory.Options opt = new BitmapFactory.Options();opt.inSampleSize = 2;mBitmap = BitmapFactory.decodeStream(is, null, opt);bm = drawableToBitamp(mContext.getResources().getDrawable(R.drawable.cross));}int disgree= 0;@Overrideprotected void onDraw(Canvas canvas) {super.onDraw(canvas);canvas.drawBitmap(mBitmap, 100, 100, null);//drawableToBitamp(mContext.getResources().getDrawable(R.drawable.ic_launcher));Drawable d = mContext.getResources().getDrawable(R.drawable.ic_launcher);int w = d.getIntrinsicWidth();int h = d.getIntrinsicHeight();d.setBounds(300, 200, 300 + w, 200 + h);d.draw(canvas);Matrix matrix = new Matrix();if(disgree > 360){disgree = 0;}disgree++;float px;float py;px = bm.getWidth()/2;py = bm.getHeight()/2;matrix.setRotate(disgree, px, py);//canvas.setMatrix(matrix);//canvas.drawBitmap(bm,550,550,null);canvas.drawBitmap(bm,matrix,null);invalidate();}private Bitmap drawableToBitamp(Drawable drawable){Bitmap bitmap;int w = drawable.getIntrinsicWidth();int h = drawable.getIntrinsicHeight();System.out.println("Drawable转Bitmap");Bitmap.Config config =drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888: Bitmap.Config.RGB_565;bitmap = Bitmap.createBitmap(w,h,config);//注意，下面三行代码要用到，否在在View或者surfaceview里的canvas.drawBitmap会看不到图Canvas canvas = new Canvas(bitmap);drawable.setBounds(0, 0, w, h);drawable.draw(canvas);return bitmap;}
}