Android——一些常用的自定义View

╰+攻爆jí腚メ 2022-06-01 03:17 223阅读 0赞

**效果图：**

![Center][]

![Center 1][]

![Center 2][]

**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

<?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"/>
    
                  </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);
    
        }
    }

[Center]: /images/20220601/38ab7e9f90b24f8890b54a2a7360de6b.png
[Center 1]: /images/20220601/4b1cd06f257c4670b1fb429be3f6e585.png
[Center 2]: /images/20220601/b8c6513d7aaa4056adc920a7cd920ed5.png