自定义VIew

自定义View实现圆形进度条

Implementing a Custom View

onDraw(android.graphics.Canvas)

onFinishInflate()

onMeasure(int, int)

onLayout(boolean, int, int, int, int)

onSizeChanged(int, int, int, int)

onDraw(android.graphics.Canvas)

onKeyDown(int, KeyEvent)

onKeyUp(int, KeyEvent)

onTrackballEvent(MotionEvent)

onTouchEvent(MotionEvent)

onFocusChanged(boolean, int, android.graphics.Rect)

onWindowFocusChanged(boolean)

onAttachedToWindow()

onDetachedFromWindow()

onWindowVisibilityChanged(int)

declare-styleable标签声明属性集。
attr声明属性
这里自定义View实现圆形进度条所以配置如下属性：

圆环的颜色：roundColor
进度的颜色：round
圆环的宽度（直径）：roundWidth
中间显示字体的颜色：textColor
中间显示字体的大小：textSize
最大进度：max
是否显示圆环进度中心的字体：textIsDisplayable
圆环的风格（实心或空心）：style

<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="MyView">
<attr name="roundColor" format="color"/>
<attr name="roundProgressColor" format="color"/>
<attr name="roundWidth" format="dimension"/>
<attr name="textColor" format="color"/>
<attr name="textSize" format="dimension"/>
<attr name="max" format="integer"/>
<attr name="textIsDisplayable" format="boolean"/>
<attr name="style">
<enum name="STROKE" value="0"></enum>
<enum name="FILL" value="1"></enum>
</attr>
</declare-styleable>
</resources>

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.view.View;

import com.example.administrator.defineviewbymyself.R;

/**
* Created by Administrator on 2016/7/15 0015.
*
* 对于View类
* extends Object
* implements Drawable.Callback KeyEvent.Callback AccessibilityEventSource
*/
public class MyView extends View {

/*
* 字体内容
* */
String my_text;

/*
* 画笔对象的引用
* */
private Paint mPaint;
/*
* 圆环颜色
* */
private int roundColor;
/*
* 圆环进度的颜色
* */
private int roundProgressColor;
/*
* 圆环宽度
* */
private float roundWidth;
/*
* 中间进度百分比的字符串颜色的颜色
* */
private int textColor;
/*
* 中间进度百分比的字符串颜色的大小
* */
private float textSize;
/*
* 最大进度
* */
private Integer max;
/*
* 是否显示中间进度
* */
private boolean textIsDisplayable;
/*
* 进度风格，实心或空心
* */
private int style;
/*
* 当前进度
* */
//这里把进度设置为50只是为了示例能够看到效果
   private int progress = 50;
public static final int STROKE = 0;
public static final int FILL = 1;

/*
* 该构造方法在Java代码中创建MyView对象调用
* @param Context来字
* */
public MyView(Context context) {
this(context,null);
}
/*
*在布局文件中设置MyView系统会调用该方法
* AttributeSet attrs与属性相关的一些东西
* 在资源文件中配置
* */
public MyView(Context context, AttributeSet attrs) {
this(context, attrs,0);
}

/*
* int defStyleAttr MyView的默认样式
* */
public MyView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);

mPaint = new Paint();

TypedArray mTypedArray = context.obtainStyledAttributes(attrs,R.styleable.MyView);
//获取自定义属性或默认值
roundColor = mTypedArray.getColor(R.styleable.MyView_roundColor, Color.RED);
roundProgressColor = mTypedArray.getColor(R.styleable.MyView_roundProgressColor,Color.GREEN);
textColor = mTypedArray.getColor(R.styleable.MyView_textColor,Color.GREEN);
textSize = mTypedArray.getDimension(R.styleable.MyView_textSize,15);
roundWidth = mTypedArray.getDimension(R.styleable.MyView_roundWidth,5);
max = mTypedArray.getInteger(R.styleable.MyView_max,100);
textIsDisplayable = mTypedArray.getBoolean(R.styleable.MyView_textIsDisplayable,true);
style = mTypedArray.getInt(R.styleable.MyView_style,0);

mTypedArray.recycle();
}

/*
重写onDraw是自定义View的关键
*/
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);

/*
* 画最外层的大圆环
* */
int centre = getWidth()/2;//圆心坐标
int radius = (int) (centre - roundWidth/2);//圆环半径
mPaint.setColor(roundColor);//设置圆环的颜色
mPaint.setStyle(Paint.Style.STROKE);//设置空心
mPaint.setStrokeWidth(roundWidth);//设置圆环的宽度
mPaint.setAntiAlias(true);//消除锯齿
canvas.drawCircle(centre,centre,radius,mPaint);//画出圆环

/*
* 画进度百分比
* */
mPaint.setStrokeWidth(0);//清楚上面的设置空心线宽
mPaint.setColor(textColor);//设置字体颜色
mPaint.setTextSize(textSize);//设置字体大小
mPaint.setTypeface(Typeface.DEFAULT_BOLD);//设置字体
int percent = (int) ((float)progress/(float)max*100);//中间的进度百分比，先转换成float在进行除法运算，不然都为0
float textWidth = mPaint.measureText(percent+"%");
if(textIsDisplayable && percent != 0 && style == STROKE){
canvas.drawText(percent + "%", centre - textWidth / 2, centre + textSize/2, mPaint); //画出进度百分比
}

/*
* 画圆弧，画圆环的进度
* */
//设置进度是实心还是空心
mPaint.setStrokeWidth(roundWidth);//设置圆环的宽度
mPaint.setColor(roundProgressColor);//设置进度的颜色
RectF oval = new RectF(centre-radius,centre-radius,centre+radius,centre+radius);//用于定义的圆弧的形状和大小的界限

/*
* STROKE:代表空心
* FILL：代表实心
* */
switch (style){
case STROKE:{
mPaint.setStyle(Paint.Style.STROKE);
canvas.drawArc(oval,0,360*progress/max,false,mPaint);;
break;
}
case FILL:{
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
if(progress !=0)
canvas.drawArc(oval, 0, 360 * progress / max, true, mPaint);  //根据进度画圆弧
break;
}
}
}

public synchronized  int getMax(){
return max;
}

/*
* 设置进度的最大值
* @param max
* */
public synchronized void setMax(){
if(max < 0){
throw new IllegalArgumentException("max not less than 0");
}
this.max = max;
}

/*
* 获取进度，需要同步
* @return
* */
public synchronized int getProgress(){
return progress;
}

/**
* 设置进度，此为线程安全控件，由于考虑多线的问题，需要同步
* 刷新界面调用postInvalidate()能在非UI线程刷新
* @param 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 String getMy_text() {
return my_text;
}

public void setMy_text(String my_text) {
this.my_text = my_text;
}

public int getRoundColor() {
return roundColor;
}

public void setRoundColor(int roundColor) {
this.roundColor = roundColor;
}

public int getRoundProgressColor() {
return roundProgressColor;
}

public void setRoundProgressColor(int roundProgressColor) {
this.roundProgressColor = roundProgressColor;
}

public float getRoundWidth() {
return roundWidth;
}

public void setRoundWidth(float roundWidth) {
this.roundWidth = roundWidth;
}

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 boolean isTextIsDisplayable() {
return textIsDisplayable;
}

public void setTextIsDisplayable(boolean textIsDisplayable) {
this.textIsDisplayable = textIsDisplayable;
}

public int getStyle() {
return style;
}

public void setStyle(int style) {
this.style = style;
}
public void init(){
mPaint = new Paint();
}
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:myview="com\example\administrator\defineviewbymyself\my_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.administrator.defineviewbymyself.MainActivity">

<com.example.administrator.defineviewbymyself.my_view.MyView
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</RelativeLayout>