android 自定义进度条下载apk并更新
下载文件使用子线程,更新到UI上使用handler,效果如图:
主要代码如下:
public void downFile(final String httpUrl,final Handler handler) { new Thread(new Runnable() { @Override public void run() { try { File file = null; URL url = new URL(httpUrl); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setRequestMethod("GET"); connection.setConnectTimeout(5000); FileOutputStream fileOutputStream = null; InputStream inputStream; if (connection.getResponseCode() == 200) { inputStream = connection.getInputStream(); if (inputStream != null) { file = getFile(httpUrl); delFile(file.getAbsolutePath()); fileOutputStream = new FileOutputStream(file); byte[] buffer = new byte[1024]; int length = 0; int total = 0; int max = connection.getContentLength(); while ((length = inputStream.read(buffer)) != -1) { fileOutputStream.write(buffer, 0, length); total += length; Message msg = handler.obtainMessage(); msg.what = LoadingActivity.DOWNLOADING; msg.arg1 = (int)(total*100/max); handler.sendMessage(msg); } fileOutputStream.close(); fileOutputStream.flush(); } inputStream.close(); } Message message = handler.obtainMessage(); message.what = LoadingActivity.DOWNLOAD_COMPLETE; handler.sendMessage(message); installApk(file); } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } }).start(); } /** * 根据传过来url创建文件 * */ private File getFile(String url) { File files = new File(Environment.getExternalStorageDirectory().getAbsoluteFile(), getFilePath(url)); return files; } /** * 截取出url后面的apk的文件名 * * @param url * @return */ private String getFilePath(String url) { return url.substring(url.lastIndexOf("/"), url.length()); } /*** * 删除临时存放的文件 * * @param url * 文件路径 */ private void delFile(String url) { File myFile = new File(url); if (myFile.exists()) { myFile.delete(); } } /** * 安装APK */ private void installApk(File file) { Intent intent = new Intent(Intent.ACTION_VIEW); intent.setDataAndType(Uri.fromFile(file), "application/vnd.android.package-archive"); context.startActivity(intent); context.finish(); }
然后在handler中处理UI:
private Handler mHandler = new Handler() { public void handleMessage(Message msg) { int what = msg.what; switch(what) { case DOWNLOAD_COMPLETE: break; case DOWNLOADING: int percent = (int)msg.arg1; progressBar.setProgress(percent); break; } }; };
下面重点说下自定义的进度条
public RoundProgressBar(Context context) { this(context, null); } public RoundProgressBar(Context context, AttributeSet attrs) { this(context, attrs, 0); } public RoundProgressBar(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); paint = new Paint(); TypedArray mTypedArray = context.obtainStyledAttributes(attrs, R.styleable.RoundProgressBar); roundColor = mTypedArray.getColor(R.styleable.RoundProgressBar_roundColor, Color.RED); roundProgressColor = mTypedArray.getColor(R.styleable.RoundProgressBar_roundProgressColor, Color.GREEN); textColor = mTypedArray.getColor(R.styleable.RoundProgressBar_textColor, Color.GREEN); textSize = mTypedArray.getDimension(R.styleable.RoundProgressBar_textSize, 15); roundWidth = mTypedArray.getDimension(R.styleable.RoundProgressBar_roundWidth, 5); max = mTypedArray.getInteger(R.styleable.RoundProgressBar_max, 100); textIsDisplayable = mTypedArray.getBoolean(R.styleable.RoundProgressBar_textIsDisplayable, true); style = mTypedArray.getInt(R.styleable.RoundProgressBar_style, 0); mTypedArray.recycle(); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); int centre = getWidth()/2; int radius = (int) (centre - roundWidth/2); paint.setColor(roundColor); paint.setStyle(Paint.Style.STROKE); paint.setStrokeWidth(roundWidth); paint.setAntiAlias(true); canvas.drawCircle(centre, centre, radius, paint); paint.setStrokeWidth(0); paint.setColor(textColor); paint.setTextSize(textSize); paint.setTypeface(Typeface.DEFAULT_BOLD); int percent = (int)(((float)progress / (float)max) * 100); float textWidth = paint.measureText(percent + "%"); if(textIsDisplayable && percent != 0 && style == STROKE){ canvas.drawText(percent + "%", centre - textWidth / 2, centre + textSize/2, paint); } paint.setStrokeWidth(roundWidth); paint.setColor(roundProgressColor); RectF oval = new RectF(centre - radius, centre - radius, centre + radius, centre + radius); switch (style) { case STROKE:{ paint.setStyle(Paint.Style.STROKE); canvas.drawArc(oval, 0, 360 * progress / max, false, paint); break; } case FILL:{ paint.setStyle(Paint.Style.FILL_AND_STROKE); if(progress !=0) canvas.drawArc(oval, 0, 360 * progress / max, true, paint); break; } } } public synchronized int getMax() { return max; } public synchronized void setMax(int max) { if(max < 0){ throw new IllegalArgumentException("max not less than 0"); } this.max = max; } public synchronized int getProgress() { return progress; } public synchronized void setProgress(int progress) { if(progress < 0){ throw new IllegalArgumentException("progress not less than 0"); } if(progress > max){ progress = max; } if(progress <= max){ this.progress = progress; postInvalidate(); } } public int getCricleColor() { return roundColor; } public void setCricleColor(int cricleColor) { this.roundColor = cricleColor; } public int getCricleProgressColor() { return roundProgressColor; } public void setCricleProgressColor(int cricleProgressColor) { this.roundProgressColor = cricleProgressColor; } public int getTextColor() { return textColor; } public void setTextColor(int textColor) { this.textColor = textColor; } public float getTextSize() { return textSize; } public void setTextSize(float textSize) { this.textSize = textSize; } public float getRoundWidth() { return roundWidth; } public void setRoundWidth(float roundWidth) { this.roundWidth = roundWidth; }
类RoundProgressBar继承于view,基本属性在attr.xml中去定义,而我们需要关注的是setProgress(),因为封装的RoundProgressBar,我们都是通过调用setProgress()方法去刷新进度,在这个方法中也是不断调用postInvalidate()方法,即不断去draw,接下来就是我们的重头戏onDraw()了:
我们可以将此view分为三部分,
1. 圆形的圈(空心的);
2. 中间的文字加百分比符号,统一为字符串;
3. 弧形的圈。
通过这样分析,就简单啦~
自定义view少不了跟android的画笔paint和canvas打交道。
paint.setColor(roundColor); paint.setStyle(Paint.Style.STROKE); paint.setStrokeWidth(roundWidth); paint.setAntiAlias(true); canvas.drawCircle(centre, centre, radius, paint);
其中的canvas.drawCircle(float cx, float cy, float radius, Paint paint)表示以(cx,cy) 为中心,radius为半径画一个圆。paint.setStrokeWidth(roundWidth)表示画的圆的外围的宽度。
这样我们的空心圆就出来了~
接下来就是画中间的字符串:
paint.setStrokeWidth(0); paint.setColor(textColor);paint.setTextSize(textSize);paint.setTypeface(Typeface.DEFAULT_BOLD); int percent = (int)(((float)progress / (float)max) * 100); float textWidth = paint.measureText(percent + "%"); canvas.drawText(percent + "%", centre - textWidth / 2, centre + textSize/2, paint);
其中canvas.(String text, float x, float y, Paint paint)表示以坐标(x,y)为中心,画出文字text,这里我们使用paint.measureText(text)方法,使得画出的文字能居中。
最后就是画弧度了:
paint.setStrokeWidth(roundWidth); paint.setColor(roundProgressColor); RectF oval = new RectF(centre - radius, centre - radius, centre+radius, centre + radius); paint.setStyle(Paint.Style.STROKE);canvas.drawArc(oval, 0, 360 * progress / max, false, paint);
canvas.drawArc(RectF oval, float startAngle, float sweepAngle, boolean useCenter, Paint paint)表示用长方形画出sweepAngle角度的弧度。这里我试了设置画笔Paint.Style.STROKE和Paint.Style.FILL_AND_STROKE效果一样的,然后就是长方形的四个坐标,找了半天没找到笔,只能口述了~假设有个中心点center,那左上角left的物理坐标就是centre-left,以此类推~
好了,自定义进度条下载apk并更新已讲解完,自己也对自定义view有更好的理解了,哈哈~
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