Android自定义控件之自定义ViewGroup实现标签云

来源：互联网发布：李善姬在韩国地位知乎编辑：程序博客网时间：2024/04/27 10:25

实现的功能：

这里写图片描述

基本绘制流程：

构造函数获取自定义属性
onMeasure()方法，测量子控件的大小
onLayout()方法，对子控件进行布局

1、自定义属性

<resources>    <declare-styleable name="TabsViewGroup">        <attr name="tabVerticalSpace" format="dimension" />        <attr name="tabHorizontalSpace" format="dimension" />    </declare-styleable></resources>

2、构造函数中获取自定义属性值

    public TabsViewGroup(Context context, AttributeSet attrs) {        super(context, attrs);        TypedArray attrArray = context.obtainStyledAttributes(attrs, R.styleable.TabsViewGroup);        if (attrArray != null) {            childHorizontalSpace = attrArray.getDimensionPixelSize(R.styleable.TabsViewGroup_tabHorizontalSpace, 0);            childVerticalSpace = attrArray.getDimensionPixelSize(R.styleable.TabsViewGroup_tabHorizontalSpace, 0);            attrArray.recycle();        }    }

3、onMeasure函数测量子控件大小，然后设置当前控件大小

 @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        int widthSize = MeasureSpec.getSize(widthMeasureSpec);        int heightSize = MeasureSpec.getSize(heightMeasureSpec);        int widthModel = MeasureSpec.getMode(widthMeasureSpec);        int heightModel = MeasureSpec.getMode(heightMeasureSpec);        //输出宽度高度以及测量模式        Log.i(TAG, "sizeWidth :" + widthSize);        switch (widthModel) {            case MeasureSpec.AT_MOST:                Log.i(TAG, "Width model AT_MOST");                break;            case MeasureSpec.EXACTLY:                Log.i(TAG, "Width model EXACTLY");                break;            case MeasureSpec.UNSPECIFIED:                Log.i(TAG, "Width model UNSPECIFIED");                break;        }        Log.i(TAG, "sizeHeight :" + heightSize);        switch (heightModel) {            case MeasureSpec.AT_MOST:                Log.i(TAG, "Height model AT_MOST");                break;            case MeasureSpec.EXACTLY:                Log.i(TAG, "Height model EXACTLY");                break;            case MeasureSpec.UNSPECIFIED:                Log.i(TAG, "Height model UNSPECIFIED");                break;        }        //左右边距        int left = getPaddingLeft();        int top = getPaddingTop();        //记录每一行的宽度和高度        int lineWidth = 0;        int lineHeight = 0;        // 如果是warp_content情况下，记录宽和高        int containerWidth = 0;        int containerHeight = 0;        // 遍历每个子元素        for (int index = 0; index < getChildCount(); index++) {            View child = getChildAt(index);            if (child.getVisibility() == GONE) {                continue;            }            measureChild(child, widthMeasureSpec, heightMeasureSpec);            MarginLayoutParams params = (MarginLayoutParams) child.getLayoutParams();            int childWidth = child.getMeasuredWidth() + params.leftMargin + params.rightMargin + childHorizontalSpace;            int childHeight = child.getMeasuredHeight() + params.topMargin + params.bottomMargin + childVerticalSpace;            if (lineWidth + childWidth > widthSize - getPaddingRight() - getPaddingLeft()) {                containerWidth = Math.max(lineWidth, childWidth);                lineWidth = childWidth;                containerHeight += lineHeight;                lineHeight = childHeight;                Rect rect = new Rect(left,                        containerHeight + top,                        left + childWidth - childHorizontalSpace,                        containerHeight + top + child.getMeasuredHeight());                child.setTag(rect);            } else {                Rect rect = new Rect(lineWidth + left,                        containerHeight + top,                        lineWidth + left + childWidth - childHorizontalSpace,                        containerHeight + top + child.getMeasuredHeight());                child.setTag(rect);                lineWidth += childWidth;                lineHeight = Math.max(lineHeight, childHeight);            }        }        containerWidth = Math.max(containerWidth, lineWidth) + getPaddingLeft() + getPaddingRight();        containerHeight += lineHeight + getPaddingTop() + getPaddingBottom();        containerHeight -= childVerticalSpace;        setMeasuredDimension(widthModel == MeasureSpec.EXACTLY ? widthSize : containerWidth,                heightModel == MeasureSpec.EXACTLY ? heightSize : containerHeight);    }

4、onLayout函数对所有子控件重新布局

  @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        int childCount = getChildCount();        for (int i = 0; i < childCount; i++) {            View child = getChildAt(i);            if (child.getVisibility() == GONE) {                continue;            }            Rect location = (Rect) child.getTag();            child.layout(location.left, location.top, location.right, location.bottom);        }    }

使用方法

1、布局问自己中直接引用

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:owen="http://schemas.android.com/apk/res-auto"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="#ffffff"    android:orientation="vertical">    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:padding="10dp"        android:textSize="16sp"        android:text="国际足球"/>    <View        android:layout_width="wrap_content"        android:layout_height="0.1dp"        android:background="#e0e0e0"/>    <com.ownchan.tabviewgroup.view.TabsViewGroup        android:id="@+id/tabs_view"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:padding="10dip"        owen:tabHorizontalSpace="10dp"        owen:tabVerticalSpace="10dp" /></LinearLayout>

2、代码添加标签

   @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();    }    private void initView() {        TabsViewGroup tabsViewGroup = (TabsViewGroup) findViewById(R.id.tabs_view);        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,                ViewGroup.LayoutParams.WRAP_CONTENT);        String[] tabs = new String[]{"世预赛欧洲区",                "世预赛南美区", "五人世界杯", "意甲", "美国大联盟", "乌超", "英冠", "国际冠军杯", "巴西圣保罗州杯", "巴西杯"};        for (int i = 0; i < tabs.length; i++) {            TextView textView = new TextView(this);            textView.setText(tabs[i]);            textView.setTextColor(Color.WHITE);            textView.setBackgroundDrawable(getResources().getDrawable(R.drawable.tabs_bg));            textView.setGravity(Gravity.CENTER);            textView.setPadding(10, 0, 10, 0);            textView.setTextSize(16);            tabsViewGroup.addView(textView, params);        }    }

效果图：

xiaoguo

项目Github地址

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