android 通过canvas旋转 绘制文字 竖直等不同方向的显示

效果如下：

主体代码如下：

package com.free.chart;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.view.SurfaceHolder;import android.view.SurfaceView;public class DrawTextStudy extends SurfaceView implements SurfaceHolder.Callback {    SurfaceHolder holder;    public DrawTextStudy(Context context) {        super(context);        // TODO Auto-generated constructor stub        holder = this.getHolder();        holder.addCallback(this);    }    @Override    public void surfaceChanged(SurfaceHolder holder, int format, int width,            int height) {        // TODO Auto-generated method stub            }    @Override    public void surfaceCreated(SurfaceHolder holder) {        // TODO Auto-generated method stub        new Thread(new MyThread()).start();    }    @Override    public void surfaceDestroyed(SurfaceHolder holder) {        // TODO Auto-generated method stub            }        void drawText(Canvas canvas ,String text , float x ,float y,Paint paint ,float angle){        if(angle != 0){            canvas.rotate(angle, x, y);         }        canvas.drawText(text, x, y, paint);        if(angle != 0){            canvas.rotate(-angle, x, y);         }    }        class MyThread implements Runnable{        @Override        public void run() {            // TODO Auto-generated method stub            Canvas canvas = null;                try{                                        canvas = holder.lockCanvas();                Paint paint = new Paint();                                paint.setColor(Color.WHITE);                paint.setTextSize(20);                                canvas.drawLine(100, 100, 100, 400, paint);                drawText(canvas,"Hello", 80, 200, paint,-90);                                        paint.setColor(Color.RED);                paint.setTextSize(40);                drawText(canvas,"free", 150, 180, paint,-45);                                        paint.setColor(Color.BLUE);                drawText(canvas,"World", 150, 80, paint,0);                canvas.drawLine(100, 100, 400, 100, paint);                            } catch(Exception e){                            } finally {                holder.unlockCanvasAndPost(canvas);            }                            }            }    }

activity调用

public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);                setContentView(new DrawTextStudy(this));}