用边距来实现绝对定位是错误的。如果您需要利润,那将不会扩大规模。
从 Android 窃取代码,对其进行修改,然后使用您的“未弃用”绝对布局。
AbsoluteLayout 被弃用是因为他们不想支持它,而不是因为它不起作用。
搞砸了,他们的布局不能满足我们的需要,那么他们有什么建议呢?自定义视图。
所以这里是(重构,没有样式(puke)支持):
/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RemoteViews.RemoteView;
/**
* A layout that lets you specify exact locations (x/y coordinates) of its
* children. Absolute layouts are less flexible and harder to maintain than
* other types of layouts without absolute positioning.
*
*/
@RemoteView
public class DCAbsoluteLayout extends ViewGroup {
int mPaddingLeft, mPaddingRight, mPaddingTop, mPaddingBottom;
public DCAbsoluteLayout(Context context) {
super(context);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int count = getChildCount();
int maxHeight = 0;
int maxWidth = 0;
// Find out how big everyone wants to be
measureChildren(widthMeasureSpec, heightMeasureSpec);
// Find rightmost and bottom-most child
for (int i = 0; i < count; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
int childRight;
int childBottom;
DCAbsoluteLayout.LayoutParams lp
= (DCAbsoluteLayout.LayoutParams) child.getLayoutParams();
childRight = lp.x + child.getMeasuredWidth();
childBottom = lp.y + child.getMeasuredHeight();
maxWidth = Math.max(maxWidth, childRight);
maxHeight = Math.max(maxHeight, childBottom);
}
}
// Account for padding too
maxWidth += mPaddingLeft + mPaddingRight;
maxHeight += mPaddingTop + mPaddingBottom;
// Check against minimum height and width
maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight());
maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());
setMeasuredDimension(resolveSizeAndState(maxWidth, widthMeasureSpec, 0),
resolveSizeAndState(maxHeight, heightMeasureSpec, 0));
}
/**
* Returns a set of layout parameters with a width of
* {@link ViewGroup.LayoutParams#WRAP_CONTENT},
* a height of {@link ViewGroup.LayoutParams#WRAP_CONTENT}
* and with the coordinates (0, 0).
*/
@Override
protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, 0, 0);
}
@Override
protected void onLayout(boolean changed, int l, int t,
int r, int b) {
int count = getChildCount();
for (int i = 0; i < count; i++) {
View child = getChildAt(i);
if (child.getVisibility() != GONE) {
DCAbsoluteLayout.LayoutParams lp =
(DCAbsoluteLayout.LayoutParams) child.getLayoutParams();
int childLeft = mPaddingLeft + lp.x;
int childTop = mPaddingTop + lp.y;
child.layout(childLeft, childTop,
childLeft + child.getMeasuredWidth(),
childTop + child.getMeasuredHeight());
}
}
}
// Override to allow type-checking of LayoutParams.
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p instanceof DCAbsoluteLayout.LayoutParams;
}
@Override
protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
return new LayoutParams(p);
}
@Override
public boolean shouldDelayChildPressedState() {
return false;
}
public static class LayoutParams extends ViewGroup.LayoutParams {
/**
* The horizontal, or X, location of the child within the view group.
*/
public int x;
/**
* The vertical, or Y, location of the child within the view group.
*/
public int y;
/**
* Creates a new set of layout parameters with the specified width,
* height and location.
*
* @param width the width, either {@link #MATCH_PARENT},
{@link #WRAP_CONTENT} or a fixed size in pixels
* @param height the height, either {@link #MATCH_PARENT},
{@link #WRAP_CONTENT} or a fixed size in pixels
* @param x the X location of the child
* @param y the Y location of the child
*/
public LayoutParams(int width, int height, int x, int y) {
super(width, height);
this.x = x;
this.y = y;
}
/**
* {@inheritDoc}
*/
public LayoutParams(ViewGroup.LayoutParams source) {
super(source);
}
}
}
一般来说,Android UI 是一场噩梦。考虑为整个项目使用 webview。就使用该系统而言,“没关系”,但该 UI 是一个火车残骸。
HTML 一直是样式和动态 UI 内容的首选方式。没有其他东西可以与之匹敌,只有自定义绘制的 UI(在性能方面)。