原文地址：http://blog.csdn.net/xiaanming/article/details/10298163
很多的时候，系统自带的View满足不了我们功能的需求，那么我们就需要自己来自定义一个能满足我们需求的View,自定义View我们需要先继承View，添加类的构造方法，重写父类View的一些方法，例如onDraw，为了我们自定义的View在一个项目中能够重用，有时候我们需要自定义其属性，举个很简单的例子，我在项目中的多个界面使用我自定义的View，每个界面该自定义View的颜色都不相同，这时候如果没有自定义属性，那我们是不是需要构建不同颜色的View出来呢，这样子我们的代码就会显得很沉厄，所以这时候我们就需要自定义其属性来满足我们不同的需求，自定义属性呢，我们需要在values下建立attrs.xml文件，在其中定义我们需要定义的属性，然后在自定义View中也要做相对应的修改，我们还是用一个小例子来看看自定义View和自定义属性的使用
今天带大家来自己定义一个带进度的圆形进度条，我们还是先看一下效果吧
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从上面可以看出，我们可以自定义圆环的颜色，圆环进度的颜色，是否显示进度的百分比，进度百分比的颜色，以及进度是实心还是空心等等，这样子是不是很多元化很方便呢？接下来我们就来教大家怎么来定义
1.在values下面新建一个attrs.xml，现在里面定义我们的属性，不同的属性对应不同的format，属性对应的format可以参考http://blog.csdn.net/pgalxx/article/details/6766677，介绍的还是比较详细，接下来我贴上我在自定义这个进度条所用到的属性
- <?xmlversion="1.0"encoding="UTF-8"?>
- <resources>
- <declare-styleablename="RoundProgressBar">
- <attrname="roundColor"format="color"/>
- <attrname="roundProgressColor"format="color"/>
- <attrname="roundWidth"format="dimension"></attr>
- <attrname="textColor"format="color"/>
- <attrname="textSize"format="dimension"/>
- <attrname="max"format="integer"></attr>
- <attrname="textIsDisplayable"format="boolean"></attr>
- <attrname="style">
- <enumname="STROKE"value="0"></enum>
- <enumname="FILL"value="1"></enum>
- </attr>
- </declare-styleable>
- </resources>
<?xml version="1.0" encoding="UTF-8"?>
<resources>
<declare-styleable name="RoundProgressBar">
<attr name="roundColor" format="color"/>
<attr name="roundProgressColor" format="color"/>
<attr name="roundWidth" format="dimension"></attr>
<attr name="textColor" format="color" />
<attr name="textSize" format="dimension" />
<attr name="max" format="integer"></attr>
<attr name="textIsDisplayable" format="boolean"></attr>
<attr name="style">
<enum name="STROKE" value="0"></enum>
<enum name="FILL" value="1"></enum>
</attr>
</declare-styleable>
</resources>
2.自定义View的属性我们算是定义好了，接下来就是怎么获取属性和代码的编写了，我们需要在构造方法中获取我们自己定义的相关属性，我们先调用context.obtainStyledAttributes(attrs,R.styleable.RoundProgressBar)来获取TypedArray，然后从TypedArray获取我们定义的属性，例如
- 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);
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);
上面的代码中，如roundColor = mTypedArray.getColor(R.styleable.RoundProgressBar_roundColor, Color.RED); getColor方法的第一个参数是我们在XML文件中定义的颜色，如果我们没有给我们自定义的View定义颜色，他就会使用第二个参数中的默认值，即Color.RED
3.为了方便大家理解，我将自定义View的全部代码贴出来，里面的代码我也有详细的注释
- package com.example.roundprogressbar;
-
- 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.util.Log;
- import android.view.View;
-
- import com.example.circlepregress.R;
-
-
- publicclass RoundProgressBar extends View {
-
-
- private Paint paint;
-
-
-
- privateint roundColor;
-
-
-
- privateint roundProgressColor;
-
-
-
- privateint textColor;
-
-
-
- privatefloat textSize;
-
-
-
- privatefloat roundWidth;
-
-
-
- privateint max;
-
-
-
- privateint progress;
-
-
- privateboolean textIsDisplayable;
-
-
-
- privateint style;
-
- publicstaticfinalint STROKE = 0;
- publicstaticfinalint FILL = 1;
-
- 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
- protectedvoid 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);
-
- Log.e("log", centre + "");
-
-
-
- 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;
- }
- }
-
- }
-
-
- publicsynchronizedint getMax() {
- return max;
- }
-
-
-
- publicsynchronizedvoid setMax(int max) {
- if(max < 0){
- thrownew IllegalArgumentException("max not less than 0");
- }
- this.max = max;
- }
-
-
-
- publicsynchronizedint getProgress() {
- return progress;
- }
-
-
-
- publicsynchronizedvoid setProgress(int progress) {
- if(progress < 0){
- thrownew IllegalArgumentException("progress not less than 0");
- }
- if(progress > max){
- progress = max;
- }
- if(progress <= max){
- this.progress = progress;
- postInvalidate();
- }
-
- }
-
-
- publicint getCricleColor() {
- return roundColor;
- }
-
- publicvoid setCricleColor(int cricleColor) {
- this.roundColor = cricleColor;
- }
-
- publicint getCricleProgressColor() {
- return roundProgressColor;
- }
-
- publicvoid setCricleProgressColor(int cricleProgressColor) {
- this.roundProgressColor = cricleProgressColor;
- }
-
- publicint getTextColor() {
- return textColor;
- }
-
- publicvoid setTextColor(int textColor) {
- this.textColor = textColor;
- }
-
- publicfloat getTextSize() {
- return textSize;
- }
-
- publicvoid setTextSize(float textSize) {
- this.textSize = textSize;
- }
-
- publicfloat getRoundWidth() {
- return roundWidth;
- }
-
- publicvoid setRoundWidth(float roundWidth) {
- this.roundWidth = roundWidth;
- }
-
-
-
- }
package com.example.roundprogressbar;
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.util.Log;
import android.view.View;
import com.example.circlepregress.R;
/**
* 仿iphone带进度的进度条，线程安全的View，可直接在线程中更新进度
* @author xiaanming
*
*/
public class RoundProgressBar extends View {
/**
* 画笔对象的引用
*/
private Paint paint;
/**
* 圆环的颜色
*/
private int roundColor;
/**
* 圆环进度的颜色
*/
private int roundProgressColor;
/**
* 中间进度百分比的字符串的颜色
*/
private int textColor;
/**
* 中间进度百分比的字符串的字体
*/
private float textSize;
/**
* 圆环的宽度
*/
private float roundWidth;
/**
* 最大进度
*/
private int max;
/**
* 当前进度
*/
private int progress;
/**
* 是否显示中间的进度
*/
private boolean textIsDisplayable;
/**
* 进度的风格，实心或者空心
*/
private int style;
public static final int STROKE = 0;
public static final int FILL = 1;
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);
//获取自定义属性和默认值
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);
/**
* 画最外层的大圆环
*/
int centre = getWidth()/2; //获取圆心的x坐标
int radius = (int) (centre - roundWidth/2); //圆环的半径
paint.setColor(roundColor); //设置圆环的颜色
paint.setStyle(Paint.Style.STROKE); //设置空心
paint.setStrokeWidth(roundWidth); //设置圆环的宽度
paint.setAntiAlias(true); //消除锯齿
canvas.drawCircle(centre, centre, radius, paint); //画出圆环
Log.e("log", centre + "");
/**
* 画进度百分比
*/
paint.setStrokeWidth(0);
paint.setColor(textColor);
paint.setTextSize(textSize);
paint.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 = paint.measureText(percent + "%"); //测量字体宽度，我们需要根据字体的宽度设置在圆环中间
if(textIsDisplayable && percent != 0 && style == STROKE){
canvas.drawText(percent + "%", centre - textWidth / 2, centre + textSize/2, paint); //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
paint.setStrokeWidth(roundWidth); //设置圆环的宽度
paint.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
switch (style) {
case STROKE:{
paint.setStyle(Paint.Style.STROKE);
canvas.drawArc(oval, 0, 360 * progress / max, false, paint); //根据进度画圆弧
break;
}
case FILL:{
paint.setStyle(Paint.Style.FILL_AND_STROKE);
if(progress !=0)
canvas.drawArc(oval, 0, 360 * progress / max, true, paint); //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(int max) {
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 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;
}
}
4.通过上面几步我们就实现了自定义View,和自定义View的属性，当然使用过程中还是有一点变化，我们必须在界面布局的最顶层加上
xmlns:android_custom="http://schemas.android.com/apk/res/com.example.circlepregress"这个即命名空间，
- 红色部分是自定义属性的前缀，什么意思呢？对于android系统控件我们定义其控件属性是用android:XXX="XXXXXXX",而我们自己定义的就用android_custom:XXX = "XXXXXX"
- 绿色部分则是我们的包的名字
通过上面这两步我们就能自己定义属性了,我贴出自定义View在XML中使用情况
- <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
- xmlns:android_custom="http://schemas.android.com/apk/res/com.example.circlepregress"
- xmlns:tools="http://schemas.android.com/tools"
- android:layout_width="match_parent"
- android:layout_height="match_parent" >
-
-
- <com.example.roundprogressbar.RoundProgressBar
- android:id="@+id/roundProgressBar2"
- android:layout_width="80dip"
- android:layout_height="80dip"
- android:layout_alignLeft="@+id/roundProgressBar1"
- android:layout_alignParentBottom="true"
- android:layout_marginBottom="78dp"
-
-
- android_custom:roundColor="#D1D1D1"
- android_custom:roundProgressColor="@android:color/black"
- android_custom:textColor="#9A32CD"
- android_custom:textIsDisplayable="false"
- android_custom:roundWidth="10dip"
- android_custom:textSize="18sp"/>
- </RelativeLayout>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:android_custom="http://schemas.android.com/apk/res/com.example.circlepregress"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<com.example.roundprogressbar.RoundProgressBar
android:id="@+id/roundProgressBar2"
android:layout_width="80dip"
android:layout_height="80dip"
android:layout_alignLeft="@+id/roundProgressBar1"
android:layout_alignParentBottom="true"
android:layout_marginBottom="78dp"
android_custom:roundColor="#D1D1D1"
android_custom:roundProgressColor="@android:color/black"
android_custom:textColor="#9A32CD"
android_custom:textIsDisplayable="false"
android_custom:roundWidth="10dip"
android_custom:textSize="18sp"/>
</RelativeLayout>
今天就到此结束，如果大家有什么疑问，请留言，我会及时回复大家的
项目源码，点击下载
本文转自Work Hard Work Smart博客园博客，原文链接：http://www.cnblogs.com/linlf03/p/3577828.html，如需转载请自行联系原作者
