androidcanvas

目录:

1、使用SurfaceView画一张图2、自定义view绘制一张图

我开始认真研究Android多媒体的开发，拓宽多媒体的技术层面，在Android中画一张图有三种方式:SurfaceView、ImageView和Custom View。

1、使用SurfaceView画一张图

包com . example . tongjiangsong . surface view demo；导入Android . content . context；导入Android . graphics . canvas；导入Android . graphics . color；导入Android . graphics . paint；导入Android . graphics . path；导入Android . util . attributeset；导入Android . view . motion event；导入Android . view . surface holder；导入Android . view . surface view；公共类CommonSurfaceView扩展SurfaceView实现SurfaceHolder。回调，Runnable { private surface holder m holder；私人画布mCanvas私有路径mPath私漆mPaint//线程私有线程mThread进行绘制；//线程状态标志(线程控制开关)私有布尔isRunning私有int drawXprivate int drawYpublic common surface view(Context Context){ this(Context，null)；} public common surface view(Context Context，AttributeSet attrs){ this(Context，attrs，0)；} public common surface view(Context Context，AttributeSet attrs，int defStyleAttr) { super(context，attrs，defStyleAttr)；//初始化m holder = get holder()；mholder . add callback(this)；//管理生命周期mPath = new Path()；//初始化画笔MP aint = new Paint()；MP int . set style(Paint。Style .笔画)；mpaint . setstrokewidth(6)；MP aint . setantialias(true)；mPaint.setColor(Color。红色)；setFocusable(true)；setFocusableInTouchMode(true)；this . setkeepscreenon(true)；} @ Override public void surface created(surface holder holder){ is running = true；mThread =新线程(this)；mthread . start()；//Start thread } @ override public void surface已更改(surface holder，int format，int width，int height){ } @ override public void surface已销毁(surface holder){ is running = false；}/* * *注意这是在子线程*/@ override public void run(){ while(正在运行){ draw x++；drawY =(int)(100 * Math . sin(drawX * 2 * Math。PI/180)+400)；mPath.lineTo(drawX，drawY)；draw()；}}/* * *注意这是在子线程中绘制的，表面支持子线程更新ui，所以*/private void draw(){ canvas canvas = null；//锁定画布，防止线程安全，防止内存区域被其他线程共享。canvas = mholder . lock canvas()；if (null！= canvas) {//清除屏幕或者设置背景canvas.drawColor(Color。白色)；canvas.drawPath(mPath，mPaint)；//提交显示视图并解锁它，以防止它占用此内存mholder。长时间解锁canvasandPost(画布)；}}}输出结果:

2、使用自定义view绘制一张图

包com . example . tongjiangsong . view demo；导入Android . content . context；导入Android . graphics . canvas；导入Android . graphics . color；导入Android . graphics . paint；导入Android . util . attributeset；导入Android . view . motion event；导入Android . view . view；导入Ja . util . random；公共类BallView扩展了View { private Context mContext私有属性集mAttrs私漆油漆；//定义画笔公共球视图(context上下文){ super(context)；this.mContext = context//初始化画笔init paint()；} public BallView(Context context，AttributeSet attrs){ super(Context，attrs)；this.mContext = contextthis.mAttrs = attrsinit paint()；} public BallView(Context context，AttributeSet attrs，int defStyleAttr) { super(context，attrs，defStyleAttr)；this.mContext = contextthis.mAttrs = attrsinit paint()；}私有void init Paint(){ Paint = new Paint()；}//重写onDraw方法实现画图操作@ override protected void onDraw(canvas canvas){ super。ondraw(帆布)；paint . setantialias(false)；//将画笔设置为无锯齿paint.setColor(Color。黑色)；//设置画笔颜色canvas.drawColor(Color。白色)；//白色背景paint . setstrokewidth((float)3.0)；//线宽paint . set style(paint . style . stroke)；/空心形效果画布。画圆(50，50，10，画)；//画一个圆形canvas.drawcircle (100，100，20，paint)；//绘制圆形画布。画圆(150，150，30，画)；//画一个圆形canvas.drawcircle (200，200，40，paint)；//画一个圆形canvas.drawcircle (250，250，50，paint)；//画一个圆形canvas.drawcircle (300，300，60，paint)；//画一个圆形canvas.drawcircle (350，350，70，paint)；//画一个圆}}输出结果:

​

我的CSDN博客地址:https://blog.csdn.net/tong5956.