正文
今天我們來自定義一個ViewGroup砰碴，讓它可以根據(jù)圖片的數(shù)量顯示不同的布局
我們在微信逛朋友圈的時候會看到有圖片的朋友圈垒在，當(dāng)只有一張圖片的時候镰吵，顯示是鋪滿所在區(qū)域的，當(dāng)有9張的時候旺入，是九宮格的形式顯示的兑凿，那么我們能不能根據(jù)圖片的數(shù)量顯示不同的布局呢凯力，比如兩張的時候我想讓其均分，三張的時候我想一張大圖在左礼华，另外兩張小圖在右咐鹤，還有其他數(shù)量也可以自己想象
你有沒有想到用什么方法實現(xiàn)這個需求呢，你可能會想到用不同的布局文件圣絮，只要你不嫌麻煩祈惶，因為你的布局?jǐn)?shù)量和圖片數(shù)量是成正比的，所以布局是比較浪費資源的扮匠，那有什么好方法嗎捧请，當(dāng)然有，就是我們今天要講的自定義ViewGroup
正式開始
我們知道ViewGroup是控件的組合棒搜，它可以添加View到其內(nèi)部疹蛉，我們可以新建一個類并繼承ViewGroup
public class VideoLayout extends ViewGroup {
public VideoLayout(Context context) {
this(context, null);
}
public VideoLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
@Override
protected void onLayout(boolean b, int i, int i1, int i2, int i3) {
}
}
我們重寫一個ViewGroup來滿足今天的需求其實需要重寫onMeasure和onLayout方法，還有一個onDraw方法不用管
我們創(chuàng)建好之后就可以開始編寫代碼了力麸，下面是完整代碼
PostContentLayout.java
package com.yk.mchat.app.widget;
import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
public class PostContentLayout extends ViewGroup {
public static final int PIC_ONE = 1;
public static final int PIC_TWO = 2;
public static final int PIC_THREE = 3;
public static final int PIC_FOUR = 4;
public static final int PIC_FIVE = 5;
public static final int PIC_SIX = 6;
public static final int PIC_SEVEN = 7;
public static final int PIC_EIGHT = 8;
public static final int PIC_NINE = 9;
public PostContentLayout(Context context) {
super(context);
}
public PostContentLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int childCount = getChildCount();
if (childCount == 0) {
return;
}
switch (childCount) {
case PIC_ONE:
onMeasureOne(widthMeasureSpec, heightMeasureSpec);
break;
case PIC_TWO:
onMeasureTwo(widthMeasureSpec, heightMeasureSpec);
break;
case PIC_THREE:
onMeasureThree(widthMeasureSpec, heightMeasureSpec);
break;
case PIC_FOUR:
onMeasureFour(widthMeasureSpec, heightMeasureSpec);
break;
case PIC_FIVE:
onMeasureFive(widthMeasureSpec, heightMeasureSpec);
break;
case PIC_SIX:
onMeasureSix(widthMeasureSpec, heightMeasureSpec);
break;
case PIC_SEVEN:
onMeasureSeven(widthMeasureSpec, heightMeasureSpec);
break;
case PIC_EIGHT:
onMeasureEight(widthMeasureSpec, heightMeasureSpec);
break;
case PIC_NINE:
onMeasureNice(widthMeasureSpec, heightMeasureSpec);
break;
default:
break;
}
}
private void onMeasureOne(int widthMeasureSpec, int heightMeasureSpec) {
View child = getChildAt(0);
child.measure(widthMeasureSpec, heightMeasureSpec);
}
private void onMeasureTwo(int widthMeasureSpec, int heightMeasureSpec) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
int childWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 2, MeasureSpec.EXACTLY);
child.measure(childWidth, heightMeasureSpec);
}
}
private void onMeasureThree(int widthMeasureSpec, int heightMeasureSpec) {
int childCount = getChildCount();
View mainChild = getChildAt(0);
int mainChildWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 2, MeasureSpec.EXACTLY);
mainChild.measure(mainChildWidth, heightMeasureSpec);
for (int i = 1; i < childCount; i++) {
View child = getChildAt(i);
int childWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 2, MeasureSpec.EXACTLY);
int childHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 2, MeasureSpec.EXACTLY);
child.measure(childWidth, childHeight);
}
}
private void onMeasureFour(int widthMeasureSpec, int heightMeasureSpec) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
int childWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 2, MeasureSpec.EXACTLY);
int childHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 2, MeasureSpec.EXACTLY);
child.measure(childWidth, childHeight);
}
}
private void onMeasureFive(int widthMeasureSpec, int heightMeasureSpec) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
int childWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 2, MeasureSpec.EXACTLY);
int childHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 2, MeasureSpec.EXACTLY);
child.measure(childWidth, childHeight);
}
for (int i = 2; i < childCount; i++) {
View child = getChildAt(i);
int childWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 3, MeasureSpec.EXACTLY);
int childHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 2, MeasureSpec.EXACTLY);
child.measure(childWidth, childHeight);
}
}
private void onMeasureSix(int widthMeasureSpec, int heightMeasureSpec) {
int childCount = getChildCount();
View mainChild = getChildAt(0);
int mainChildWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 3 * 2, MeasureSpec.EXACTLY);
int mainChildHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 3 * 2, MeasureSpec.EXACTLY);
mainChild.measure(mainChildWidth, mainChildHeight);
for (int i = 1; i < childCount; i++) {
View child = getChildAt(i);
int childWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 3, MeasureSpec.EXACTLY);
int childHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 3, MeasureSpec.EXACTLY);
child.measure(childWidth, childHeight);
}
}
private void onMeasureSeven(int widthMeasureSpec, int heightMeasureSpec) {
int childCount = getChildCount();
View mainChild = getChildAt(0);
int mainChildWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 2, MeasureSpec.EXACTLY);
int mainChildHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 2, MeasureSpec.EXACTLY);
mainChild.measure(mainChildWidth, mainChildHeight);
for (int i = 1; i < childCount; i++) {
View child = getChildAt(i);
int childWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 2, MeasureSpec.EXACTLY);
int childHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 4, MeasureSpec.EXACTLY);
child.measure(childWidth, childHeight);
}
}
private void onMeasureEight(int widthMeasureSpec, int heightMeasureSpec) {
int childCount = getChildCount();
View mainChild = getChildAt(0);
int mainChildWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 4 * 3, MeasureSpec.EXACTLY);
int mainChildHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 4 * 3, MeasureSpec.EXACTLY);
mainChild.measure(mainChildWidth, mainChildHeight);
for (int i = 1; i < childCount; i++) {
View child = getChildAt(i);
int childWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 4, MeasureSpec.EXACTLY);
int childHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 4, MeasureSpec.EXACTLY);
child.measure(childWidth, childHeight);
}
}
private void onMeasureNice(int widthMeasureSpec, int heightMeasureSpec) {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
int childWidth = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec) / 3, MeasureSpec.EXACTLY);
int childHeight = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec) / 3, MeasureSpec.EXACTLY);
child.measure(childWidth, childHeight);
}
}
@Override
protected void onLayout(boolean b, int i, int i1, int i2, int i3) {
int childCount = getChildCount();
if (childCount == 0) {
return;
}
switch (childCount) {
case PIC_ONE:
onLayoutOne();
break;
case PIC_TWO:
onLayoutTwo();
break;
case PIC_THREE:
onLayoutThree();
break;
case PIC_FOUR:
onLayoutFour();
break;
case PIC_FIVE:
onLayoutFive();
break;
case PIC_SIX:
onLayoutSix();
break;
case PIC_SEVEN:
onLayoutSeven();
break;
case PIC_EIGHT:
onLayoutEight();
break;
case PIC_NINE:
onLayoutNine();
break;
default:
break;
}
}
private void onLayoutOne() {
View child = getChildAt(0);
child.layout(0, 0, child.getMeasuredWidth(), child.getMeasuredHeight());
}
private void onLayoutTwo() {
int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * i, 0, child.getMeasuredWidth() * (i + 1), child.getMeasuredHeight());
}
}
private void onLayoutThree() {
int childCount = getChildCount();
View mainChild = getChildAt(0);
mainChild.layout(0, 0, mainChild.getMeasuredWidth(), mainChild.getMeasuredHeight());
for (int i = 1; i < childCount; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth(), child.getMeasuredHeight() * (i - 1), child.getMeasuredWidth() * 2, child.getMeasuredHeight() * i);
}
}
private void onLayoutFour() {
int childCount = getChildCount();
for (int i = 0; i < 2; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * i, 0, child.getMeasuredWidth() * (i + 1), child.getMeasuredHeight());
}
for (int i = 2; i < childCount; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * (i - 2), child.getMeasuredHeight(), child.getMeasuredWidth() * (i - 1), child.getMeasuredHeight() * 2);
}
}
private void onLayoutFive() {
int childCount = getChildCount();
for (int i = 0; i < 2; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * i, 0, child.getMeasuredWidth() * (i + 1), child.getMeasuredHeight());
}
for (int i = 2; i < childCount; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * (i - 2), child.getMeasuredHeight(), child.getMeasuredWidth() * (i - 1), child.getMeasuredHeight() * 2);
}
}
private void onLayoutSix() {
int childCount = getChildCount();
View mainChild = getChildAt(0);
mainChild.layout(0, 0, mainChild.getMeasuredWidth(), mainChild.getMeasuredHeight());
for (int i = 1; i < 3; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * 2, child.getMeasuredHeight() * (i - 1), child.getMeasuredWidth() * 3, child.getMeasuredHeight() * i);
}
for (int i = 3; i < childCount; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * (i - 3), child.getMeasuredHeight() * 2, child.getMeasuredWidth() * (i - 2), child.getMeasuredHeight() * 3);
}
}
private void onLayoutSeven() {
int childCount = getChildCount();
View mainChild = getChildAt(0);
mainChild.layout(0, 0, mainChild.getMeasuredWidth(), mainChild.getMeasuredHeight());
for (int i = 1; i < 3; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth(), child.getMeasuredHeight() * (i - 1), child.getMeasuredWidth() * 2, child.getMeasuredHeight() * i);
}
for (int i = 3; i < 5; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * (i - 3), child.getMeasuredHeight() * 2, child.getMeasuredWidth() * (i - 2), child.getMeasuredHeight() * 3);
}
for (int i = 5; i < childCount; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * (i - 5), child.getMeasuredHeight() * 3, child.getMeasuredWidth() * (i - 4), child.getMeasuredHeight() * 4);
}
}
private void onLayoutEight() {
int childCount = getChildCount();
View mainChild = getChildAt(0);
mainChild.layout(0, 0, mainChild.getMeasuredWidth(), mainChild.getMeasuredHeight());
for (int i = 1; i < 4; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * 3, child.getMeasuredHeight() * (i - 1), child.getMeasuredWidth() * 4, child.getMeasuredHeight() * i);
}
for (int i = 4; i < childCount; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * (i - 4), child.getMeasuredHeight() * 3, child.getMeasuredWidth() * (i - 3), child.getMeasuredHeight() * 4);
}
}
private void onLayoutNine() {
int childCount = getChildCount();
for (int i = 0; i < 3; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * i, 0, child.getMeasuredWidth() * (i + 1), child.getMeasuredHeight());
}
for (int i = 3; i < 6; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * (i - 3), child.getMeasuredHeight(), child.getMeasuredWidth() * (i - 2), child.getMeasuredHeight() * 2);
}
for (int i = 6; i < 9; i++) {
View child = getChildAt(i);
child.layout(child.getMeasuredWidth() * (i - 6), child.getMeasuredHeight() * 2, child.getMeasuredWidth() * (i - 5), child.getMeasuredHeight() * 3);
}
}
}
里面的方法都寫得比較清楚可款，你可以復(fù)制下來，然后試著往這個ViewGroup中addView
今天就到這里克蚂。
