android 开发 ScrollView 控件的一些api描述与自定义ScrollView接口回调方法

1.正常使用ScrollView控件的一些api详解。

package com.example.lenovo.mydemoapp.scrollViewDemo;

import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.LinearLayout;
import android.widget.ScrollView;
import android.widget.TextView;

import com.example.lenovo.mydemoapp.GuidePage;
import com.example.lenovo.mydemoapp.R;

public class MyScrollViewDemo extends AppCompatActivity {
    private final String TAG = "MyScrollViewDemo";
    private ScrollView mScrollView;
    private LinearLayout ll;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my_scroll_view_demo);
        mScrollView = (ScrollView)findViewById(R.id.ScrollView);
       // View view1 =   mScrollView.getChildAt(0);
       // FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams)view1.getLayoutParams();
       // Log.e(TAG, "Child is weght:" +lp.width);
        //布局参数是 根据当前布局的父类布局，
        // 例如当前的ScrollView的父类布局实际上是LinearLayout所以写成： LinearLayout.LayoutParams
        //另外布局参数的参数其实是高度和宽度的大小
        LinearLayout.LayoutParams mSlp = new LinearLayout.LayoutParams(
                ViewGroup.LayoutParams.WRAP_CONTENT, 
                ViewGroup.LayoutParams.WRAP_CONTENT);
        //设置高度和宽度
        mSlp.width = 300;
        mSlp.height = 500;
        //设置居中
        mSlp.gravity = Gravity.CENTER_HORIZONTAL;
        //显示水平滚动条
        //mScrollView.setHorizontalScrollBarEnabled(false);
        //显示垂直滚动条
        mScrollView.setVerticalScrollBarEnabled(false);
        //配置布局参数
        mScrollView.setLayoutParams(mSlp);
        //滚动条大小
        //mScrollView.setScrollBarSize(10);
        //滚动条音效
        //mScrollView.setSoundEffectsEnabled(false);
        //滚动条样式
        //mScrollView.setScrollBarStyle();
        //在淡入淡出前设置滚动条默认延迟
        //mScrollView.setScrollBarDefaultDelayBeforeFade();
        //水平淡入淡入效果
        //mScrollView.setHorizontalFadingEdgeEnabled();
       //垂直淡入淡入效果
        mScrollView.setVerticalFadingEdgeEnabled(true);
        //淡入淡出边缘长度
        mScrollView.setFadingEdgeLength(100);
        //允许ScrollView的子控件填满ScrollView控件
        mScrollView.setFillViewport(true);
        //箭头按键是否可以执行滚动
        //mScrollView.setSmoothScrollingEnabled(false);
        ll = (LinearLayout)findViewById(R.id.ScrollView_layout);
        //因为ScrollView 布局实际上是继承FrameLayout 布局的 所以布局参数也是设置为FrameLayout
        FrameLayout.LayoutParams mLp = new FrameLayout.LayoutParams(
                ViewGroup.LayoutParams.WRAP_CONTENT, 
                ViewGroup.LayoutParams.WRAP_CONTENT);
        mLp.gravity = Gravity.CENTER_HORIZONTAL;//设置横向居中
        //设置高度和宽度
        mLp.width = 200;
        mLp.height = 500;
        ll.setLayoutParams(mLp);
        //设置外边距
        mLp.setMargins(10,50,10,0);
        //设置内边距
        ll.setPadding(10,10,10,10);
        int i=0;
        do{
            TextView textView = new TextView(this);
            textView.setTextSize(40f);
            textView.setGravity(Gravity.CENTER);
            if(i==0) {
                textView.setText(" ");
            }else if(i==21){
                textView.setText(" ");
            }else {
                textView.setText("" + i);
            }
            i++;
            Log.e(TAG, "i="+i );
            ll.addView(textView);

        }while (i<22);

        mScrollView.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                    /*
                        ACTION_MOVE 移动
                        ACTION_MASK 隐藏
                        ACTION_DOWN 按下
                        ACTION_UP 按起
                        ACTION_CANCEL 取消
                        ACTION_OUTSIDE 外面
                        ACTION_POINTER_DOWN 指向下
                        ACTION_POINTER_UP 指向上
                        ACTION_HOVER_MOVE 来回移动
                        ACTION_SCROLL 滚动
                        ACTION_HOVER_ENTER 来回输入
                        ACTION_HOVER_EXIT 来回输出
                        ACTION_BUTTON_PRESS 按钮按下
                        ACTION_BUTTON_RELEASE 按键释放
                        ACTION_POINTER_INDEX_MASK 指针数值隐藏
                        ACTION_POINTER_INDEX_SHIFT  指针数值变化
                     */
                    switch (event.getAction()){
                        case MotionEvent.ACTION_MOVE:
                            Log.e(TAG, "开始滚动");
                            Log.e(TAG, "当前getScaleY:"+mScrollView.getScaleY());
                            Log.e(TAG, "当前getPivotY:"+mScrollView.getPivotY());
                            break;
                        case MotionEvent.ACTION_MASK:
                            Log.e(TAG, "停止滚动");
                            Log.e(TAG, "当前getPivotY:"+mScrollView.getPivotY());
                            break;
                        default:
                            break;

                    }

                return false;
            }
        });

    }
}

效果图：

2.自定义重写ScrollView的class，里面将onScrollChanged的坐标数据回调出去

package com.example.lenovo.mydemo.myScrollViewDemo;

import android.content.Context;
import android.util.AttributeSet;
import android.widget.ScrollView;

/**
 * Created by lenovo on 2018/6/26.
 */

public class MyScrollView extends ScrollView {
    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);
    }

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

        }
    }
    private OnScrollChangedListener onScrollChangedListener;
    public void setOnScrollChangedListener(OnScrollChangedListener onScrollChangedListener){
        this.onScrollChangedListener = onScrollChangedListener;

    }
    public abstract interface OnScrollChangedListener{
        public abstract void  onScrollChanged (int t,int oldt);

    }
}

3.使用这个重写的ScrollView

package com.example.lenovo.mydemo.myScrollViewDemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

import com.example.lenovo.mydemo.R;

public class MyScroll extends AppCompatActivity {
    private String TAG = "MyScroll";
    private MyScrollView myScrollView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my_scroll);
        myScrollView = (MyScrollView)findViewById(R.id.scroll_1);
        myScrollView.setOnScrollChangedListener(new MyScrollView.OnScrollChangedListener() {
            @Override
            public void onScrollChanged(int t, int oldt) {
                Log.e(TAG, "控件布局高度："+myScrollView.getHandler());
                //getMeasuredHeight 和 getHandler 不能在onCreate 重写方法中使用，否则会返回0或者null
                Log.e(TAG, "控件布局实际高度："+myScrollView.getChildAt(0).getMeasuredHeight());
                Log.e(TAG, "new Y = "+t);
                Log.e(TAG, "old Y = "+oldt );
            }
        });

    }
}

效果图：

效果图2：

接口回调例子2：

//注意 接口了按键监听
public class ChildListAdapter extends RecyclerView.Adapter<ChildListAdapter.ViewHolder> implements View.OnClickListener{
    private final String TAG = "HomePageRecyclerAdapter";
    private List<ChildListData> mList;
    private Context mContext;
    public ChildListAdapter(Context context, List<ChildListData> list){
        this.mContext = context;
        this.mList = list;
    }

    @Override
    public ChildListAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.main_child_list,parent,false);
        ViewHolder viewHolder = new ViewHolder(view);
        view.setOnClickListener(this);//添加按键监听
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(ChildListAdapter.ViewHolder holder, int position) {
        ChildListData childListData = mList.get(position);
        //传入整组数据
        holder.itemView.setTag(childListData);
        holder.name.setText(childListData.getName());
        Bitmap bt = BitmapFactory.decodeFile(childListData.getFilePath());
        if(bt != null){
            Drawable drawable = new BitmapDrawable(mContext.getResources(),bt);
            holder.imageView.setImageDrawable(drawable);
        }else {
            Log.e(TAG, "没有获取到头像，使用默认头像");
            holder.imageView.setImageResource(R.mipmap.default_avatar);
        }

    }

    @Override
    public int getItemCount() {
        return mList.size();
    }

    @Override
    public void onClick(View v) {
        if(mOnItemClickListener != null){
            mOnItemClickListener.onItemClick(v, (ChildListData)v.getTag());//回调数据
        }
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        ImageView imageView;
        TextView name;
        public ViewHolder(View itemView) {
            super(itemView);
            imageView = (ImageView)itemView.findViewById(R.id.HomePage_row_image);
            name =  (TextView)itemView.findViewById(R.id.HomePage_row_name);
        }
    }
    public static interface OnRecyclerViewItemClickListener{
        void onItemClick(View view, ChildListData childListData);
    }

    private OnRecyclerViewItemClickListener mOnItemClickListener = null;

    public void setOnItemClickListener(OnRecyclerViewItemClickListener listener){
        this.mOnItemClickListener = listener;

    }
}