1

在一个 Android 应用程序中，我有一个列表视图，其中背景仅在一个角上圆角。

<shape xmlns:android="http://schemas.android.com/apk/res/android"
>
<stroke
    android:width="0dip"
    android:color="@color/content_screen_scroll_view_border"
    />
<padding
    android:left="0dip"
    android:top="@dimen/content_screen_scroll_view_border"             
    android:right="0dip" 
    android:bottom="@dimen/content_screen_scroll_view_border"
    />
<corners
    android:bottomRightRadius="20dip"
    />
<gradient
    android:angle="270"
    android:startColor="@color/listview_selected_item_start"
    android:endColor="@color/listview_selected_item_end"
    android:type="linear"
    />

当我上下翻页然后选择底部条目时，所选条目超出圆角。我尝试了各种解决方案，但没有找到一种似乎只适用于一个圆角的解决方案。

在此处输入图像描述

所以，我使用了我找到的以下代码（不记得在哪里）：

package org.pskink.roundlist;

import android.app.Activity;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.GradientDrawable;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;


public class RoundListTest extends Activity {
    private ListView mList;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mList = (ListView) findViewById(R.id.list);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1);
        adapter.add("One");
        adapter.add("Two");
        adapter.add("Three");
        adapter.add("Four");
        adapter.add("Five");
        adapter.add("Six");
        adapter.add("Seven");
        adapter.add("Eight");
        adapter.add("Nine");
        adapter.add("Ten");
        adapter.add("Eleven");
        adapter.add("Twelve");
        mList.setAdapter(adapter);
        mList.setSelector(new Selector(mList));
        mList.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);

        GradientDrawable gd = new GradientDrawable();
        gd.setColor(0xffaaaaaa);
        gd.setCornerRadii(new float[]{0,0,0,0,0,0,20,20});
        mList.setBackgroundDrawable(gd);
    }

    class Selector extends Drawable {
        private static final String TAG = "Selector";
        private Paint mPaint;
        private AdapterView mList;
        private RectF mRectF;

        public Selector(AdapterView list) {
            mList = list;
            mPaint = new Paint();
            mPaint.setColor(0x80ff8000);
            mRectF = new RectF();
        }

        @Override
        public void draw(Canvas canvas) {
            Rect b = getBounds();
            int position = mList.getSelectedItemPosition();

            canvas.save();
            canvas.clipRect(b.left, b.top, b.right, (b.bottom + b.top) / 2);
            drawHalf(canvas, b, position == 0);
            canvas.restore();
            canvas.save();
            canvas.clipRect(b.left, (b.bottom + b.top) / 2, b.right, b.bottom);
            drawHalf(canvas, b, position == mList.getAdapter().getCount() - 1 && b.bottom == mList.getHeight());
            canvas.restore();
            Log.d(TAG, "draw " + b);
        }

        private void drawHalf(Canvas canvas, Rect b ,boolean round) {
            if (round) {
                mRectF.set(b);
                canvas.drawRoundRect(mRectF, 20, 20, mPaint);
            } else {
                canvas.drawRect(b, mPaint);
            }
        }

        @Override
        public int getOpacity() {
            return 0;
        }

        @Override
        public void setAlpha(int alpha) {
        }

        @Override
        public void setColorFilter(ColorFilter cf) {
        }
    }
}

package org.pskink.roundlist;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Path;
import android.graphics.Path.Direction;
import android.graphics.RectF;
import android.graphics.drawable.GradientDrawable;
import android.graphics.drawable.GradientDrawable.Orientation;
import android.graphics.drawable.StateListDrawable;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.ListView;

public class RoundedRectListView extends ListView {

    private static final float RADIUS = 16;
    private Path mClip;

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

    private void init() {
        GradientDrawable gd = new GradientDrawable();
        gd.setCornerRadius(RADIUS);
        gd.setColor(0xff208020);
        setBackgroundDrawable(gd);
        setCacheColorHint(0);
        setVerticalFadingEdgeEnabled(false);

        StateListDrawable sld = new StateListDrawable();
        sld.addState(
                PRESSED_ENABLED_STATE_SET,
                new GradientDrawable(Orientation.LEFT_RIGHT, new int[] {0xffa58cf5, 0xffa13f99}));
        sld.addState(
                EMPTY_STATE_SET,
                new GradientDrawable(Orientation.LEFT_RIGHT, new int[] {0xff058cf5, 0xff013f99}));
        setSelector(sld);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        Log.d("onSizeChanged", "sizes" + w + " , " + h + " , " + oldw + " , " + oldh + " , ");
        mClip = new Path();
        RectF rect = new RectF(0, 0, w, h);
        mClip.addRoundRect(rect, RADIUS, RADIUS, Direction.CW);
    }

    @Override
    protected void dispatchDraw(Canvas canvas) {
        Log.d("dispatchDraw","");
        canvas.save();
        canvas.clipPath(mClip);
        super.dispatchDraw(canvas);
        canvas.restore();
    }
}

并使用 RoundedRectListView 作为布局中列表视图的对象：

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:padding="8dip"
>
    <org.pskink.roundlist.RoundedRectListView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/list"
    />
</LinearLayout>

然后发生的事情是，除了左下角之外，它会绕过所有角落。我似乎无法弄清楚如何让它只圆左下角的那个。

4

0 回答 0