如何以编程方式使用笔画绘制圆形? [英] How to make a circular drawable with stroke, programmatically?

问题描述

背景

我正在尝试创建一个实心圆，具有特定颜色和宽度的笔触，并在其中添加一个图像.

这可以在 XML 中轻松完成，因此(这只是一个示例):

<项目><shape android:shape="椭圆形"><尺寸android:width="120dp" android:height="120dp"/><solid android:color="#ffff0000"/><中风android:width="3dp" android:color="#ff00ff00"/></形状></项目><项目android:width="60dp" android:height="60dp" android:drawable="@android:drawable/btn_star"机器人:重力=中心"/></层列表>

问题

我需要有上面的某些属性以编程方式改变，所以我不能使用XML文件，但想法还是一样的.

问题是，我找不到像在 XML 中那样在 OvalShape 可绘制对象上添加笔划的简单方法.我找不到执行此操作的函数.

我尝试了什么

StackOverflow 上有一些解决方案，但我找不到一个效果很好的解决方案.我找到的只有一个是

解决方案

您可以以编程方式执行此操作
在 YourActivity.XMl 中，像往常一样设置 ImageView.

在你的 MainActivity.java

 ImageView iV = (ImageView) findViewById(R.id.id1);intstrokeWidth = 5;int strokeColor = Color.parseColor("#03dc13");int fillColor = Color.parseColor("#ff0000");GradientDrawable gD = new GradientDrawable();gD.setColor(fillColor);gD.setShape(GradientDrawable.OVAL);gD.setStroke(strokeWidth,strokeColor);iV.setBackground(gD);

setColor 这里设置背景颜色，setStroke 设置描边宽度和描边颜色.
我为颜色、宽度等创建了一些局部变量，以使其更易于理解.
结果

填充越多，圆圈的大小就会增加越多.

Background

I'm trying to have a filled circle, with a stroke of certain color and width, and an image inside.

This can easily be done in XML, as such (this is just a sample) :

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="oval">
            <size
                android:width="120dp" android:height="120dp"/>
            <solid android:color="#ffff0000"/>
            <stroke
                android:width="3dp" android:color="#ff00ff00"/>
        </shape>
    </item>
    <item
        android:width="60dp" android:height="60dp" android:drawable="@android:drawable/btn_star"
        android:gravity="center"/>
</layer-list>

The problem

I need to have certain properties of the above to change programmatically, so I can't use the XML file, but the idea is still the same.

Thing is, I can't find an easy way to put a stroke on an OvalShape drawable, as done in XML. I can't find the function to do it.

What I tried

There are solutions out there here on StackOverflow, but I couldn't find one that works well. Only one I've found is here, but its stroke line is being cut .

I have, however, partially succeeded in one way to solve this, by using an XML just for the stroke itself:

stroke_drawable.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval">
    <stroke
        android:width="4dp" android:color="@android:color/white"/>
</shape>

code:

    final int strokeDrawableResId = R.drawable.stroke_drawable;
    Drawable innerDrawable = ResourcesCompat.getDrawable(getResources(), ..., null);
    final Drawable strokeDrawable = ResourcesCompat.getDrawable(getResources(), strokeDrawableResId, null);
    ShapeDrawable biggerCircle = new ShapeDrawable(new OvalShape());
    int size = ...;
    biggerCircle.setIntrinsicHeight(size);
    biggerCircle.setIntrinsicWidth(size);
    biggerCircle.getPaint().setColor(0xffff0000);
    biggerCircle.setBounds(new Rect(0, 0, size, size));
    LayerDrawable layerDrawable = new LayerDrawable(new Drawable[]{biggerCircle, strokeDrawable, innerDrawable});

    ImageView imageView = findViewById(R.id.imageView);
    imageView.setImageDrawable(layerDrawable);

It works, but it's not fully programmatically (stroke is defined in XML).

The question

How to change the code to be fully programmatic ?

---

EDIT: I tried what was suggested here, yet instead of an additional drawable for a background, since I needed it all in one drawable, I used LayerDrawable:

    Drawable innerDrawable = ResourcesCompat.getDrawable(getResources(), android.R.drawable.btn_star, null);
    int strokeWidth = 5;
    int strokeColor = Color.parseColor("#ff0000ff");
    int fillColor = Color.parseColor("#ffff0000");
    GradientDrawable gD = new GradientDrawable();
    gD.setColor(fillColor);
    gD.setShape(GradientDrawable.OVAL);
    gD.setStroke(strokeWidth, strokeColor);
    LayerDrawable layerDrawable = new LayerDrawable(new Drawable[]{gD, innerDrawable});
    ImageView imageView = findViewById(R.id.imageView);
    imageView.setImageDrawable(layerDrawable);

This works, but for some reason the drawable inside (the star) is being stretched:

解决方案

You can do this programmatically as
In YourActivity.XMl, Set-up an ImageView as usual.

<ImageView
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:id="@+id/id1"
            android:src="@mipmap/ic_launcher_round"                                
            android:padding="15dp"/>

And in your MainActivity.java

    ImageView iV = (ImageView) findViewById(R.id.id1);
    int strokeWidth = 5;
    int strokeColor = Color.parseColor("#03dc13");
    int fillColor = Color.parseColor("#ff0000");
    GradientDrawable gD = new GradientDrawable();
    gD.setColor(fillColor);
    gD.setShape(GradientDrawable.OVAL);
    gD.setStroke(strokeWidth, strokeColor);
    iV.setBackground(gD);

setColor here sets the background color and setStroke sets the stroke width and stroke color.
I have created some local variables for color, width etc to make it more easy to understand.
Result

More you increase the padding, more will the size of circle increase.

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