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：
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); }
}
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; }
}