Android SurfaceView画板操作

本文实例为大家分享了Android SurfaceView画板操作的具体代码，供大家参考，具体内容如下

画板——画路径

package com.example.review.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/**
* 画板画路径
*/
public class HuabanView extends SurfaceView implements SurfaceHolder.Callback {

private SurfaceHolder surfaceHolder;
private Path path = new Path();

public HuabanView(Context context) {
 super(context);
}

public HuabanView(Context context, AttributeSet attrs) {
 super(context, attrs);
 surfaceHolder = getHolder();
 surfaceHolder.addCallback(this);//获得surfaceview的生命周期
}

public HuabanView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
}

public HuabanView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
 super(context, attrs, defStyleAttr, defStyleRes);
}

@Override
public void surfaceCreated(SurfaceHolder holder) {
 new HuabanThread().start();
}

@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {

}

@Override
public boolean onTouchEvent(MotionEvent event) {
 float x = event.getX();
 float y = event.getY();
 int action = event.getAction();
 if (action == MotionEvent.ACTION_DOWN) {//按下
  path.moveTo(x, y);
 } else if (action == MotionEvent.ACTION_MOVE) {//移动
  path.lineTo(x, y);
 }
 return true;
}

class HuabanThread extends Thread {
 @Override
 public void run() {
  super.run();
  //TODO:画笔
  Paint paint = new Paint();
  paint.setColor(Color.BLACK);
  paint.setStrokeWidth(20);
  paint.setStyle(Paint.Style.STROKE);
  paint.setAntiAlias(true);
  //TODO:画布
  while (true) {
   Canvas canvas = surfaceHolder.lockCanvas();
   //避免空指针
   if (canvas == null){
    return;
   }
   canvas.drawColor(Color.WHITE, PorterDuff.Mode.CLEAR);
   canvas.drawColor(Color.WHITE);
   canvas.drawPath(path,paint);
   surfaceHolder.unlockCanvasAndPost(canvas);
  }
 }
}
public void close(){
 path.reset();
}
}

画板——画动态直线

package com.example.review.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/**
* 画板画路径
* 画动态直线
*/
public class LineView extends SurfaceView implements SurfaceHolder.Callback {

private SurfaceHolder surfaceHolder;
private Path path = new Path();
private int x = 0;

public LineView(Context context) {
 super(context);
}

public LineView(Context context, AttributeSet attrs) {
 super(context, attrs);
 surfaceHolder = getHolder();
 surfaceHolder.addCallback(this);//获得surfaceview的生命周期
}

public LineView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
}

public LineView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
 super(context, attrs, defStyleAttr, defStyleRes);
}

@Override
public void surfaceCreated(SurfaceHolder holder) {
 new HuabanThread().start();
}

@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {

}

class HuabanThread extends Thread {
 @Override
 public void run() {
  super.run();
  //TODO:画笔
  Paint paint = new Paint();
  paint.setColor(Color.BLACK);
  paint.setStrokeWidth(20);
  paint.setStyle(Paint.Style.STROKE);
  paint.setAntiAlias(true);
  //TODO:画布
  while (true) {
   Canvas canvas = surfaceHolder.lockCanvas();
   //避免空指针
   if (canvas == null){
    return;
   }
   canvas.drawColor(Color.WHITE, PorterDuff.Mode.CLEAR);
   canvas.drawColor(Color.WHITE);
   canvas.drawLine(0,100,x++,100,paint);
   surfaceHolder.unlockCanvasAndPost(canvas);
  }
 }
}

public void close(){
 path.reset();
}

}

基本图形

//圆
canvas.drawOval(50,100,150,200,paint);
//半圆
canvas.drawArc(500,500,700,700,20,180,true,paint);
//矩形
canvas.drawRect(100,300,250,400,paint);
//三角形
canvas.drawLine(100,450,0,600,paint);
canvas.drawLine(0,600,400,600,paint);
canvas.drawLine(100,450,400,600,paint);
//梯形
canvas.drawLine(100,700,200,700,paint);
canvas.drawLine(100,700,0,900,paint);
canvas.drawLine(0,900,400,900,paint);
canvas.drawLine(200,700,400,900,paint);

//文字
canvas.drawText("截图",100,1000,paint);

来源：https://blog.csdn.net/weixin_45697390/article/details/105804970