Android中自定义进度条详解

Android原生控件只有横向进度条一种,而且没法变换样式,比如原生rom的样子

很丑是吧,当伟大的产品设计要求更换前背景,甚至纵向,甚至圆弧状的,咋办,比如:

ok,我们开始吧:

一)变换前背景

先来看看progressbar的属性:


<ProgressBar
            android:id="@+id/progressBar"
            style="?android:attr/progressBarStyleHorizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="5dip"
            android:layout_toRightOf="@+id/progressBarV"
            android:indeterminate="false"
            android:padding="2dip"
            android:progress="50" />

根据style="?android:attr/progressBarStyleHorizontal",我们找到源码中的style.xml


<style name="Widget.ProgressBar.Horizontal">
        <item name="android:indeterminateOnly">false</item>
        <item name="android:progressDrawable">@android:drawable/progress_horizontal</item>
        <item name="android:indeterminateDrawable">@android:drawable/progress_indeterminate_horizontal</item>
        <item name="android:minHeight">20dip</item>
        <item name="android:maxHeight">20dip</item>
    </style>

看到:


<item name="android:progressDrawable">@android:drawable/progress_horizontal</item>

木有,继续发掘源码,找到drawable下面的progress_horizontal.xml,这就是我们今天的主角了:

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    
    <item android:id="@android:id/background">
        <shape>
            <corners android:radius="5dip" />
            <gradient
                    android:startColor="#ff9d9e9d"
                    android:centerColor="#ff5a5d5a"
                    android:centerY="0.75"
                    android:endColor="#ff747674"
                    android:angle="270"
            />
        </shape>
    </item>
    
    <item android:id="@android:id/secondaryProgress">
        <clip>
            <shape>
                <corners android:radius="5dip" />
                <gradient
                        android:startColor="#80ffd300"
                        android:centerColor="#80ffb600"
                        android:centerY="0.75"
                        android:endColor="#a0ffcb00"
                        android:angle="270"
                />
            </shape>
        </clip>
    </item>
    
    <item android:id="@android:id/progress">
        <clip>
            <shape>
                <corners android:radius="5dip" />
                <gradient
                        android:startColor="#ffffd300"
                        android:centerColor="#ffffb600"
                        android:centerY="0.75"
                        android:endColor="#ffffcb00"
                        android:angle="270"
                />
            </shape>
        </clip>
    </item>
    
</layer-list>

看到android:id="@android:id/progress"木有,看到android:id="@android:id/secondaryProgress"木有
把这个文件复制到自己工程下的drawable,就可以随心所欲的修改shape的属性,渐变,圆角等等
那么怎么放一个图片进去呢,ok,新建progress_horizontal1.xml:


<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    
    <item android:id="@android:id/progress" android:drawable="@drawable/progressbar" />
    
</layer-list>

在android:drawable中指定你处理好的图片
然后回到布局中:


<ProgressBar
            android:id="@+id/progressBar1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/progressBar"
            android:layout_margin="5dip"
            android:layout_toRightOf="@+id/progressBarV"
            android:background="@drawable/progress_bg"
            android:indeterminate="false"
            android:indeterminateOnly="false"
            android:maxHeight="20dip"
            android:minHeight="20dip"
            android:padding="2dip"
            android:progress="50"
            android:progressDrawable="@drawable/progress_horizontal1" />

android:background="@drawable/progress_bg"指定背景
android:progressDrawable="@drawable/progress_horizontal1"前景使用上面的progress_horizontal1
ok,搞定

注意看,四角还是有圆倒角的,貌似是系统自己加上去的,总之我的图片里面是没有做这个倒角处理的
二)纵向进度条

还是得从源码入手,看回progress_horizontal.xml


<item android:id="@android:id/progress">
        <clip>
            <shape>
                <corners android:radius="5dip" />
                <gradient
                        android:startColor="#ffffd300"
                        android:centerColor="#ffffb600"
                        android:centerY="0.75"
                        android:endColor="#ffffcb00"
                        android:angle="270"
                />
            </shape>
        </clip>
    </item>

为什么shape外面要包一层clip呢,官方文档解释是clipdrawable是可以自我复制的,来看看定义


<?xml version="1.0" encoding="utf-8"?>
<clip
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:drawable="@drawable/drawable_resource"
    android:clipOrientation=["horizontal" | "vertical"]
    android:gravity=["top" | "bottom" | "left" | "right" | "center_vertical" |
                     "fill_vertical" | "center_horizontal" | "fill_horizontal" |
                     "center" | "fill" | "clip_vertical" | "clip_horizontal"] />

android:clipOrientation有两个属性,默认为horizontal
android:gravity有两个属性,默认为left
那我们试试改成vertical和bottom会有什么效果,新建一个progress_vertical.xml,把源码progress_horizontal.xml的内容复制过来,这里去掉了secondaryProgress,修改了clip,shape的渐变中心centerY改为centerX


<item android:id="@android:id/progress">
        <clip
            android:clipOrientation="vertical"
            android:gravity = "bottom">
            <shape>
                <corners android:radius="5dip" />
                <gradient
                        android:startColor="#ffffd300"
                        android:centerColor="#ffffb600"
                        android:centerX="0.75"
                        android:endColor="#ffffcb00"
                        android:angle="90"
                />
            </shape>
        </clip>
    </item>

布局中android:progressDrawable="@drawable/progress_vertical"
ok,搞定,就是这么简单:

三)弧形bar

这个也许算不上是进度条,用的也不多,最多也就仪表盘用用,不然谁会把进度条整成圆弧的呢。好吧这个可不是改改源码就能搞定的,看代码:


public class Arcs extends View {  
    private Paint mArcPaint;  
    private Paint mArcBGPaint;  
  
    private RectF mOval;  
    private float mSweep = 0;  
    private int mSpeedMax = 200;
    private int mThreshold = 100;
    private int mIncSpeedValue = 0;
    private int mCurrentSpeedValue = 0; 
    private float mCenterX;  
    private float mCenterY;  
    private float mSpeedArcWidth;  
 
    private final float SPEED_VALUE_INC = 2; 
 
    .......... 
 

首先是一堆成员变量,两个Paint用来画圆弧一个前景一个背景,一个RectF圆弧就画在上面,然后是一些控制参数比如sweep圆弧扫过的角度,xy坐标等等。


mArcPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mArcPaint.setStyle(Paint.Style.STROKE);
        mArcPaint.setStrokeWidth(mSpeedArcWidth);
//        mPaint.setStrokeCap(Paint.Cap.ROUND);
        mArcPaint.setColor(0xff81ccd6);
        BlurMaskFilter mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.INNER);
        mArcPaint.setMaskFilter(mBlur);
        
        mArcBGPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mArcBGPaint.setStyle(Paint.Style.STROKE);
        mArcBGPaint.setStrokeWidth(mSpeedArcWidth+8);
        mArcBGPaint.setColor(0xff171717);
        
        BlurMaskFilter mBGBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.INNER);
      mArcBGPaint.setMaskFilter(mBGBlur);

设置两个画笔,颜色,宽度,样式等等,BlurMaskFilter笔是边缘模糊效果,有几种,可以自己尝试。


@Override
protected void onSizeChanged(int w, int h, int ow, int oh) {
        super.onSizeChanged(w, h, ow, oh);
        Log.i("onSizeChanged w", w+"");
        Log.i("onSizeChanged h", h+"");
        mCenterX = w * 0.5f;  // remember the center of the screen
        mCenterY = h - mSpeedArcWidth;
        mOval = new RectF(mCenterX - mCenterY, mSpeedArcWidth, mCenterX + mCenterY, mCenterY * 2);
    }

重写父类View的onSizeChanged,为的是自己根据布局中的大小做居中处理


@Override  
    protected void onDraw(Canvas canvas) { 
        drawSpeed(canvas); 
        calcSpeed(); 
    } 
 
private void drawSpeed(Canvas canvas) { 
        canvas.drawArc(mOval, 179, 181, false, mArcBGPaint); 
 
        mSweep = (float) mIncSpeedValue / mSpeedMax * 180; 
        if (mIncSpeedValue > mThreshold) { 
            mArcPaint.setColor(0xFFFF0000); 
        } 
        else { 
            mArcPaint.setColor(0xFF00B0F0); 
        } 
         
        canvas.drawArc(mOval, 180, mSweep, false, mArcPaint);         
    } 
 
private void calcSpeed() { 
        if (mIncSpeedValue < mCurrentSpeedValue) { 
            mIncSpeedValue += SPEED_VALUE_INC; 
            if (mIncSpeedValue > mCurrentSpeedValue) { 
                mIncSpeedValue = mCurrentSpeedValue; 
            } 
            invalidate(); 
        } 
        else if (mIncSpeedValue > mCurrentSpeedValue) { 
            mIncSpeedValue -= SPEED_VALUE_INC; 
            if (mIncSpeedValue < mCurrentSpeedValue) { 
                mIncSpeedValue = mCurrentSpeedValue; 
            } 
            invalidate(); 
        } 
    } 

重写onDraw以便重绘canvas
drawSpeed里面
通过计算mSweep = (float) mIncSpeedValue / mSpeedMax * 180;
然后canvas.drawArc(mOval, 180, mSweep, false, mArcPaint);
会根据mSweep的变化,画出相应长度的弧度来
根据与阈值的对比,还可以设定不同的 颜色:


if (mIncSpeedValue > mThreshold) {
   mArcPaint.setColor(0xFFFF0000);
  }
  else {
   mArcPaint.setColor(0xFF00B0F0);
  }

calcSpeed通过一个步进来控制增量或减量,以使弧度自然过渡,减少跳跃
ok,大功告成。

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发布时间 2015-01-17 12:18:09
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