java - 如何使用 flowlayout (或任何自定义布局)

Question

我是android新手，一直在寻找像wpf这样的控件。我找到了一个名为 FlowLayout 的类(该类的代码位于我的问题的底部)。我在这个文件夹中添加了这个类:MyApp-src-Layouts-FlowLayout.java

在我的 mylayout.xml 中，我想在另一个布局中使用此布局:

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

    <com.myapp.FlowLayout
        android:id="@+id/FlowLayout1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true" >

    </com.myapp.FlowLayout>


</RelativeLayout>

但是我收到一个错误:无法找到以下类:- com.myapp.FlowLayout(修复构建路径、编辑 XML、创建类)

这是 FlowLayoutClass:

package Layouts;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

public class FlowLayout extends ViewGroup {

    private int line_height;

    public static class LayoutParams extends ViewGroup.LayoutParams {

        public final int horizontal_spacing;
        public final int vertical_spacing;

        /**
         * @param horizontal_spacing Pixels between items, horizontally
         * @param vertical_spacing Pixels between items, vertically
         */
        public LayoutParams(int horizontal_spacing, int vertical_spacing) {
            super(0, 0);
            this.horizontal_spacing = horizontal_spacing;
            this.vertical_spacing = vertical_spacing;
        }
    }

    public FlowLayout(Context context) {
        super(context);
    }

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

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        assert (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED);

        final int width = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();
        int height = MeasureSpec.getSize(heightMeasureSpec) - getPaddingTop() - getPaddingBottom();
        final int count = getChildCount();
        int line_height = 0;

        int xpos = getPaddingLeft();
        int ypos = getPaddingTop();

        int childHeightMeasureSpec;
        if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
            childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST);
        } else {
            childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        }

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
                child.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST), childHeightMeasureSpec);
                final int childw = child.getMeasuredWidth();
                line_height = Math.max(line_height, child.getMeasuredHeight() + lp.vertical_spacing);

                if (xpos + childw > width) {
                    xpos = getPaddingLeft();
                    ypos += line_height;
                }

                xpos += childw + lp.horizontal_spacing;
            }
        }
        this.line_height = line_height;

        if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.UNSPECIFIED) {
            height = ypos + line_height;

        } else if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
            if (ypos + line_height < height) {
                height = ypos + line_height;
            }
        }
        setMeasuredDimension(width, height);
    }

    @Override
    protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(1, 1); // default of 1px spacing
    }

    @Override
    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
        if (p instanceof LayoutParams) {
            return true;
        }
        return false;
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        final int count = getChildCount();
        final int width = r - l;
        int xpos = getPaddingLeft();
        int ypos = getPaddingTop();

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final int childw = child.getMeasuredWidth();
                final int childh = child.getMeasuredHeight();
                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
                if (xpos + childw > width) {
                    xpos = getPaddingLeft();
                    ypos += line_height;
                }
                child.layout(xpos, ypos, xpos + childw, ypos + childh);
                xpos += childw + lp.horizontal_spacing;
            }
        }
    }

}

我在这里做错了什么？

提前致谢，

比约恩

Answer 1

资源 (res) 中的布局文件夹需要 xml 文件。 Java 类属于 src 文件夹。编译器目前无法处理它。