转载地址: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
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
- <?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);
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;
-
- public class RoundProgressBar extends View {
-
- private Paint paint;
-
-
- private int roundColor;
-
-
- private int roundProgressColor;
-
-
- private int textColor;
-
-
- private float textSize;
-
-
- private float roundWidth;
-
-
- private int max;
-
-
- private int progress;
-
- private boolean textIsDisplayable;
-
-
- 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);
-
-
- 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);
-
- 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;
- }
- }
-
- }
-
-
- 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;
- }
-
-
-
- }
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>
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