Android那些事兒之自定義進度條

 Android原生控件只有橫向進度條一種，並且無法變換樣式，好比原生rom的樣子

很醜是吧，當偉大的產品設計要求更換前背景，甚至縱向，甚至圓弧狀的，咋辦，好比

ok，咱們開始吧：

 

一）變換前背景

先來看看progressbar的屬性：

<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" />

根據style="?android:attr/progressBarStyleHorizontal"，咱們找到源碼中的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，繼續發掘源碼，找到drawable下面的progress_horizontal.xml，這就是咱們今天的主角了：

<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

把這個文件複製到本身工程下的drawable，就能夠爲所欲爲的修改shape的屬性，漸變，圓角等等

那麼怎麼放一個圖片進去呢，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中指定你處理好的圖片

而後回到佈局中

<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，四角仍是有圓倒角的，貌似是系統本身加上去的，總之個人圖片裏面是沒有作這個倒角處理的

 

二）縱向進度條

仍是得從源碼入手，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>

爲何shape外面要包一層clip呢，官方文檔解釋是clipdrawable是能夠自我複製的，來看看定義

<?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有兩個屬性，默認爲horizontal

android:gravity有兩個屬性，默認爲left

那咱們試試改爲vertical和bottom會有什麼效果，新建一個progress_vertical.xml，把源碼progress_horizontal.xml的內容複製過來，這裏去掉了secondaryProgress，修改了clip，shape的漸變中心centerY改成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>

佈局中android:progressDrawable="@drawable/progress_vertical"

ok，搞定，就是這麼簡單：

 

 

三）弧形bar

這個也許算不上是進度條，用的也很少，最多也就儀表盤用用，否則誰會把進度條整成圓弧的呢。好吧這個可不是改改源碼就能搞定的，看代碼

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;

    ..........

}

首先是一堆成員變量，兩個Paint用來畫圓弧一個前景一個背景，一個RectF圓弧就畫在上面，而後是一些控制參數好比sweep圓弧掃過的角度，xy座標等等

 

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);

設置兩個畫筆，顏色，寬度，樣式等等，BlurMaskFilter筆是邊緣模糊效果，有幾種，能夠本身嘗試

 

@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);
    }

重寫父類View的onSizeChanged，爲的是本身根據佈局中的大小作居中處理

 

@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();
        }
    }

重寫onDraw以便重繪canvas

drawSpeed裏面

經過計算mSweep = (float) mIncSpeedValue / mSpeedMax * 180;

而後canvas.drawArc(mOval, 180, mSweep, false, mArcPaint);

會根據mSweep的變化，畫出相應長度的弧度來

根據與閾值的對比，還能夠設定不一樣的 顏色：

 

if (mIncSpeedValue > mThreshold) {

mArcPaint.setColor(0xFFFF0000);

}

else {

mArcPaint.setColor(0xFF00B0F0);

}

 

 

calcSpeed經過一個步進來控制增量或減量，以使弧度天然過渡，減小跳躍

ok，大功告成