Question

我有这样的布局资源，我想用布局宽度和高度来扩充它：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="75px"
    android:layout_height="25px">

    <TextView
        android:id="@+id/drawable_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:text="Name" />

    <TextView
        android:id="@+id/drawable_description"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@id/drawable_name"
        android:layout_alignParentLeft="true"
        android:gravity="center_horizontal"
        android:layout_below="@+id/drawable_name"
        android:text="Some Text" />

</RelativeLayout>

View可以是任何东西，我将其转换为Bitmap。

private Bitmap getBitmap(View v){
    v.measure(MeasureSpec.makeMeasureSpec(mDrawableWidth, MeasureSpec.EXACTLY),
              MeasureSpec.makeMeasureSpec(mDrawableHeight, MeasureSpec.EXACTLY));
    v.layout(0, 0, mDrawableWidth, mDrawableHeight);
    Bitmap returnedBitmap = Bitmap.createBitmap(mDrawableWidth, mDrawableHeight,Bitmap.Config.ARGB_8888);
    Canvas c=new Canvas(returnedBitmap);
    v.draw(c);
    return returnedBitmap;
}

到目前为止，我的宽度和高度都是硬编码的，我希望能够以编程方式进行，访问layout_width和layout_height。有没有办法实现这个目标？如果还有另一种方法用这个值给视图充气而没有在测量中指定它们，请告诉我。

如果我创建自定义视图，是否有可能指定固定的宽度和高度？

Answer 1

此示例应该有效。可能会根据您的需要进行一些调整以使其完美，但请试一试：

//Get a bitmap from a layout resource. Inflates it into a discarded LinearLayout
//so that the LayoutParams are preserved
public static Bitmap getLayoutBitmap (Context c, int layoutRes, int maxWidth, int maxHeight) {
    View view = LayoutInflater.from(c).inflate(layoutRes, new LinearLayout(c), false);
    return getViewBitmap(view, maxWidth, maxHeight);
}

public static Bitmap getViewBitmap (View v, int maxWidth, int maxHeight) {
    ViewGroup.LayoutParams vParams = v.getLayoutParams();

    //If the View hasn't been attached to a layout, or had LayoutParams set
    //return null, or handle this case however you want
    if (vParams == null) {
        return null;
    }

    int wSpec = measureSpecFromDimension(vParams.width, maxWidth);
    int hSpec = measureSpecFromDimension(vParams.height, maxHeight);

    v.measure(wSpec, hSpec);

    final int width = v.getMeasuredWidth();
    final int height = v.getMeasuredHeight();

    //Cannot make a zero-width or zero-height bitmap
    if (width == 0 || height == 0) {
        return null;
    }

    v.layout(0, 0, width, height);

    Bitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(result);
    v.draw(canvas);

    return result;
}

private static int measureSpecFromDimension (int dimension, int maxDimension) {
    switch (dimension) {
        case ViewGroup.LayoutParams.MATCH_PARENT:
            return View.MeasureSpec.makeMeasureSpec(maxDimension, View.MeasureSpec.EXACTLY);
        case ViewGroup.LayoutParams.WRAP_CONTENT:
            return View.MeasureSpec.makeMeasureSpec(maxDimension, View.MeasureSpec.AT_MOST);
        default:
            return View.MeasureSpec.makeMeasureSpec(dimension, View.MeasureSpec.EXACTLY);
    }
}

Answer 2

一种选择是以attributes的形式定义layout_width和layout_height的常量，并在getBitmap中以编程方式访问它们。

以编程方式使用预定义的度量来扩展视图

2 个答案: