Question

我想在图像背景中使用半圆形进度条。就像下图一样。

enter image description here

我试图用画布画画，但不能取得成功。我也厌倦了一些自定义进度条库但结果是一样的。

任何建议。

寻找一次性开发并在每个屏幕尺寸中使用。

Answer 1

这可以通过以一定角度剪切包含图像的画布来实现（通过绘制圆弧）。

你可以使用像这样的图像

enter image description here

通过绘制圆弧来剪切该图像。

以下是如何做到这一点。

//Convert the progress in range of 0 to 100 to angle in range of 0 180. Easy math.
float angle = (progress * 180) / 100;
mClippingPath.reset();
//Define a rectangle containing the image
RectF oval = new RectF(mPivotX, mPivotY, mPivotX + mBitmap.getWidth(), mPivotY + mBitmap.getHeight());
//Move the current position to center of rect
mClippingPath.moveTo(oval.centerX(), oval.centerY());
//Draw an arc from center to given angle
mClippingPath.addArc(oval, 180, angle);
//Draw a line from end of arc to center
mClippingPath.lineTo(oval.centerX(), oval.centerY());

一旦获得路径，就可以使用clipPath函数剪切该路径中的画布。

canvas.clipPath(mClippingPath);

这是完整代码

SemiCircleProgressBarView.java

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.View;



public class SemiCircleProgressBarView extends View {

    private Path mClippingPath;
    private Context mContext;
    private Bitmap mBitmap;
    private float mPivotX;
    private float mPivotY;

    public SemiCircleProgressBarView(Context context) {
        super(context);
        mContext = context;
        initilizeImage();
    }

    public SemiCircleProgressBarView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        initilizeImage();
    }

    private void initilizeImage() {
        mClippingPath = new Path();

        //Top left coordinates of image. Give appropriate values depending on the position you wnat image to be placed
        mPivotX = getScreenGridUnit();
        mPivotY = 0;

        //Adjust the image size to support different screen sizes
        Bitmap bitmap = BitmapFactory.decodeResource(mContext.getResources(), R.drawable.circle);
        int imageWidth = (int) (getScreenGridUnit() * 30);
        int imageHeight = (int) (getScreenGridUnit() * 30);
        mBitmap = Bitmap.createScaledBitmap(bitmap, imageWidth, imageHeight, false);
    }

    public void setClipping(float progress) {

        //Convert the progress in range of 0 to 100 to angle in range of 0 180. Easy math.
        float angle = (progress * 180) / 100;
        mClippingPath.reset();
        //Define a rectangle containing the image
        RectF oval = new RectF(mPivotX, mPivotY, mPivotX + mBitmap.getWidth(), mPivotY + mBitmap.getHeight());
        //Move the current position to center of rect
        mClippingPath.moveTo(oval.centerX(), oval.centerY());
        //Draw an arc from center to given angle
        mClippingPath.addArc(oval, 180, angle);
        //Draw a line from end of arc to center
        mClippingPath.lineTo(oval.centerX(), oval.centerY());
        //Redraw the canvas
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        //Clip the canvas
        canvas.clipPath(mClippingPath);
        canvas.drawBitmap(mBitmap, mPivotX, mPivotY, null);

    }

    private float getScreenGridUnit() {
        DisplayMetrics metrics = new DisplayMetrics();
        ((Activity)mContext).getWindowManager().getDefaultDisplay().getMetrics(metrics);
        return metrics.widthPixels / 32;
    }

}

在任何活动中使用它都非常容易。

activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <com.example.progressbardemo.SemiCircleProgressBarView
        android:id="@+id/progress"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

请注意，如果clipPath已开启，hardware acceleration功能将无效。您只能为该视图关闭硬件加速。

   //Turn off hardware accleration
  semiCircleProgressBarView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);

MainActivity.java

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        SemiCircleProgressBarView semiCircleProgressBarView = (SemiCircleProgressBarView) findViewById(R.id.progress);
        semiCircleProgressBarView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);

        semiCircleProgressBarView.setClipping(70);
    }

}

当进度发生变化时，您可以通过调用函数

来设置进度条

semiCircleProgressBarView.setClipping(progress);

例如：semiCircleProgressBarView.setClipping(50); //50% progress

enter image description here

semiCircleProgressBarView.setClipping(70); //70% progress

enter image description here

您可以使用自己的图像来满足要求。希望它有所帮助!!

修改：要将半圆移动到屏幕底部，请更改mPivotY值。像这样的东西

//In `SemiCircleProgressBarView.java`
//We don't get the canvas width and height initially, set `mPivoyY` inside `onWindowFocusChanged` since `getHeight` returns proper results by that time
        public void onWindowFocusChanged(boolean hasWindowFocus) {
            super.onWindowFocusChanged(hasWindowFocus);

            mPivotX = getScreenGridUnit();
            mPivotY = getHeight() - (mBitmap.getHeight() / 2);
        }

Answer 2

您可以尝试SeekArc Library。我知道它是一种不同类型的搜索栏，但通过一些小的自定义，您可以将它用作您的应用程序作为进度条。我做了同样的事。您只需要更改一些属性，例如
seekarc:touchInside="false" 它相当简单。

现在我的应用程序上的自定义实现看起来像这样：

Custom progressbar in CleanMaster

img src：CleanMaster at Google Play

Answer 3

这是一个高度等于宽度一半的视图。使用setter根据需要调整行为。默认情况下，进度为0，弧的宽度为20。调用setProgress（）将使给定的进度使视图无效。可以添加背景可绘制，并且进度条将绘制在顶部。

public class SemicircularProgressBar extends View {
private int mProgress;
private RectF mOval;
private RectF mOvalInner;
private Paint mPaintProgress;
private Paint mPaintClip;
private float ovalsDiff;
private Path clipPath;

public SemicircularProgressBar(Context context) {
    super(context);
    init();
}

public SemicircularProgressBar(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
}

public SemicircularProgressBar(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    init();
}

private void init() {
    mProgress = 0;
    ovalsDiff = 20;
    mOval = new RectF();
    mOvalInner = new RectF();
    clipPath = new Path();
    mPaintProgress = new Paint();
    mPaintProgress.setColor(Color.GREEN);
    mPaintProgress.setAntiAlias(true);
    mPaintClip = new Paint();
    mPaintClip.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
    mPaintClip.setAlpha(0);
    mPaintClip.setAntiAlias(true);
}


// call this from the code to change the progress displayed
public void setProgress(int progress) {
    this.mProgress = progress;
    invalidate();
}

// sets the width of the progress arc
public void setProgressBarWidth(float width) {
    this.ovalsDiff = width;
    invalidate();
}

// sets the color of the bar (#FF00FF00 - Green by default)
public void setProgressBarColor(int color){
    this.mPaintProgress.setColor(color);
}

@Override
public void onDraw(Canvas c) {
    super.onDraw(c);
    mOval.set(0, 0, this.getWidth(), this.getHeight()*2);
    mOvalInner.set(0+ovalsDiff, 0+ovalsDiff, this.getWidth()-ovalsDiff, this.getHeight()*2);
    clipPath.addArc(mOvalInner, 180, 180);
    c.clipPath(clipPath, Op.DIFFERENCE);
    c.drawArc(mOval, 180, 180f * ((float) mProgress / 100), true, mPaintProgress);
}

// Setting the view to be always a rectangle with height equal to half of its width
@Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
    int parentHeight = MeasureSpec.getSize(heightMeasureSpec);
    this.setMeasuredDimension(parentWidth/2, parentHeight);
    ViewGroup.LayoutParams params = this.getLayoutParams();
    params.width = parentWidth;
    params.height = parentWidth/2;
    this.setLayoutParams(params);
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}

Answer 4

您可以使用此库：

 compile 'com.github.lzyzsd:circleprogress:1.1.1'

例如：

   <com.github.lzyzsd.circleprogress.DonutProgress
        android:layout_marginLeft="50dp"
        android:id="@+id/donut_progress"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        custom:donut_progress="30"/>

<com.github.lzyzsd.circleprogress.ArcProgress
        android:id="@+id/arc_progress"
        android:background="#214193"
        android:layout_marginLeft="50dp"
        android:layout_width="100dp"
        android:layout_height="100dp"
        custom:arc_progress="55"
        custom:arc_bottom_text="MEMORY"/>

有关详细信息，请访问以下网站：

https://github.com/lzyzsd/CircleProgress

Answer 5

您可以使用此github library - circularseekbar。要实现半圈，您需要操作以下属性：＆＃34; app：start_angle＆＃34; ＆安培; ＆＃34;应用程序：end_angle＆＃34;

更多选项：

The Holo Seekbar library
教程显示半圆形搜索栏link to tutorial

Android：半圈进度条

5 个答案: