Android——一些常用的自定义View

效果图：

自定义View

MyLinearLayout.java

public class MyLinearLayout extends ViewGroup {

    private int marginTop = 50;
    private int marginLeft = 50;
    private int initTop = 50;
    private int initLeft = 50;
    //0 纵向 1 横向
    private int oritation;

    public MyLinearLayout(Context context) {
        this(context, null);
        MyLinearLayout myLinearLayout = new MyLinearLayout(context);
        myLinearLayout.hashCode();
    }

    public MyLinearLayout(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MyLinearLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context,attrs);
    }



    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int totalHeight = 0;
        int totalWidth = 0;
        measureChildren(widthMeasureSpec, heightMeasureSpec);

        int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
        int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);

        int modeHeight = MeasureSpec.getMode(heightMeasureSpec);
        int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);


        if (oritation == 0) {
            //判断高
            switch (modeHeight) {
                //dp match_parent
                case MeasureSpec.EXACTLY:
                    totalHeight = sizeHeight;
                    totalWidth = sizeWidth;
                    break;
                //wrap_content
                case MeasureSpec.AT_MOST:
                    for (int i = 0; i < getChildCount(); i++) {
                        View childAt = getChildAt(i);
                        totalHeight += childAt.getMeasuredHeight() + marginTop;
                        //Log.e("myMessage", "AT_MOST" + totalHeight);
                    }
                    totalHeight += initTop;
                    totalWidth = getChildAt(0).getMeasuredWidth() + marginLeft * 2;
                    break;
                case MeasureSpec.UNSPECIFIED:
                    break;
            }
        } else if (oritation == 1) {
            //判断高
            switch (modeWidth) {
                //dp match_parent
                case MeasureSpec.EXACTLY:
                    totalWidth = sizeWidth;
                    totalHeight = sizeHeight;
                    break;
                //wrap_content
                case MeasureSpec.AT_MOST:
                    for (int i = 0; i < getChildCount(); i++) {
                        View childAt = getChildAt(i);
                        totalWidth += childAt.getMeasuredWidth() + marginLeft;
                    }
                    totalWidth += initLeft;
                    totalHeight = getChildAt(0).getMeasuredHeight() + marginTop * 2;
                    break;
                case MeasureSpec.UNSPECIFIED:
                    break;
            }
        }else if (oritation == 2) {
            switch (modeHeight) {
                //dp match_parent
                case MeasureSpec.EXACTLY:
                    totalHeight = sizeHeight;
                    totalWidth = sizeWidth;
                    break;
                //wrap_content
                case MeasureSpec.AT_MOST:
                    for (int i = 0; i < getChildCount(); i++) {
                        View childAt = getChildAt(i);
                        totalHeight += childAt.getMeasuredHeight() + marginTop;
                        //Log.e("myMessage", "AT_MOST" + totalHeight);
                    }
                    totalHeight += initTop;
                    //totalWidth = getChildAt(0).getMeasuredWidth() + marginLeft * 2;
                    break;
                case MeasureSpec.UNSPECIFIED:
                    break;
            }

            switch (modeWidth) {
                //dp match_parent
                case MeasureSpec.EXACTLY:
                    totalWidth = sizeWidth;
                    totalHeight = sizeHeight;
                    break;
                //wrap_content
                case MeasureSpec.AT_MOST:
                    for (int i = 0; i < getChildCount(); i++) {
                        View childAt = getChildAt(i);
                        totalWidth += childAt.getMeasuredWidth() + marginLeft;
                    }
                    totalWidth += initLeft;
                    //otalHeight = getChildAt(0).getMeasuredHeight() + marginTop * 2;
                    break;
                case MeasureSpec.UNSPECIFIED:
                    break;
            }
        }


        setMeasuredDimension(totalWidth, totalHeight);

    }


    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        int mTop = initTop;
        int mLeft = 50;
        int childCount = getChildCount();

        for (int i = 0; i < childCount; i++) {
            View childAt = getChildAt(i);
            childAt.layout(mLeft, mTop, childAt.getMeasuredWidth() + mLeft, childAt.getMeasuredHeight() + mTop);
            if (oritation == 0) {
                mTop += childAt.getMeasuredHeight() + marginTop;
            } else if (oritation == 1) {
                mLeft += childAt.getMeasuredWidth() + marginLeft;
            } else if (oritation ==2 ) {
                mTop += childAt.getMeasuredHeight() + marginTop;
                mLeft += childAt.getMeasuredWidth() + marginLeft;
            }

        }

    }

    private void init(Context context, AttributeSet attrs) {
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.MyLinearLayout);
        oritation = typedArray.getInteger(0, 0);

    }
}

attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="MyLinearLayout">
        <attr name="oritation" format="enum">
            <enum value="0" name="vertical"/>
            <enum value="1" name="horizontal"/>
            <enum value="2" name="all"/>
        </attr>
        <attr name="oritation2" format="integer"/>
    </declare-styleable>


</resources>

activity_main.xml

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<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:cj="http://schemas.android.com/apk/res-auto"
    tools:context="com.bwie.com.myapplication.MainActivity">

    <com.bwie.com.myapplication.MyLinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        cj:oritation="horizontal"
        android:background="#6effff99">
        <TextView
            android:layout_width="100dp"
            android:layout_height="50dp"
            android:gravity="center"
            android:background="@color/colorAccent"
            android:text="礼物走一圈"/>

        <TextView
            android:layout_width="100dp"
            android:layout_height="50dp"
            android:background="#90ff33"
            android:gravity="center"
            android:text="礼物走两圈"/>

        <TextView
            android:layout_width="100dp"
            android:layout_height="50dp"
            android:background="#f00342"
            android:gravity="center"
            android:text="礼物走三圈"/>

        <!--<TextView-->
        <!--android:layout_width="100dp"-->
        <!--android:layout_height="50dp"-->
        <!--android:background="#27f003"-->
        <!--android:gravity="center"-->
        <!--android:text="@string/text_content"/>-->
    </com.bwie.com.myapplication.MyLinearLayout>

</LinearLayout>

自定义ScrollView

public class MyScrollView extends ScrollView {
    private OnScrollListener listener;

    public void setOnScrollListener(OnScrollListener listener) {
        this.listener = listener;
    }

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

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

    public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public interface OnScrollListener{
        void onScroll(int scrollY);
    }

    @Override
    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
        super.onScrollChanged(l, t, oldl, oldt);
        if(listener != null){
            listener.onScroll(t);
        }
    }
}

自定义禁止左右滑动的ViewPager

public class NoScrollViewPager extends ViewPager {
    private boolean isScroll;
    public NoScrollViewPager(Context context, AttributeSet attrs){
        super(context, attrs);
    }
    public NoScrollViewPager(Context context) {
        super(context);
    }
    /**
     * 1.dispatchTouchEvent一般情况不做处理
     *,如果修改了默认的返回值,子孩子都无法收到事件
     */
    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        return super.dispatchTouchEvent(ev);   // return true;不行
    }
    /**
     * 是否拦截
     * 拦截:会走到自己的onTouchEvent方法里面来
     * 不拦截:事件传递给子孩子
     */
    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        // return false;//可行,不拦截事件,
        // return true;//不行,孩子无法处理事件
        //return super.onInterceptTouchEvent(ev);//不行,会有细微移动
        if (isScroll){
            return super.onInterceptTouchEvent(ev);
        }else{
            return false;
        }
    }
    /**
     * 是否消费事件
     * 消费:事件就结束
     * 不消费:往父控件传
     */
    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        //return false;// 可行,不消费,传给父控件
        //return true;// 可行,消费,拦截事件
        //super.onTouchEvent(ev); //不行,
        //虽然onInterceptTouchEvent中拦截了,
        //但是如果viewpage里面子控件不是viewgroup,还是会调用这个方法.
        if (isScroll){
            return super.onTouchEvent(ev);
        }else {
            return true;// 可行,消费,拦截事件
        }
    }
    public void setScroll(boolean scroll) {
        isScroll = scroll;
    }

}

自定义的二级列表（ExpandableListView）

public class MyExListView extends ExpandableListView {
    public MyExListView(Context context) {
        this(context, null);
    }

    public MyExListView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MyExListView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,
                MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, expandSpec);
    }
}

自定义ListView（GridView）

public class MyListView extends GridView{
    public MyListView(Context context) {
        super(context);
    }

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

    public MyListView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int measureSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);
        super.onMeasure(widthMeasureSpec, measureSpec);

    }
}