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～