Android 滑动Scrollview标题栏渐变效果(仿京东toolba
Scrollview标题栏滑动渐变
仿京东样式(上滑显示下滑渐变消失)
/**
* @ClassName MyScrollView
* @Author Rex
* @Date 2021/1/27 17:38
*/
public class MyScrollView extends ScrollView {
private TranslucentListener mTranslucentListener;
public void setTranslucentListener(TranslucentListener translucentListener) {
this.mTranslucentListener = translucentListener;
}
public MyScrollView(Context context) {
this(context, null);
}
public MyScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
this(context, attrs, defStyleAttr, 0);
}
public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if (mTranslucentListener != null) {
//ScrollView滑出高度
int scrollY = getScrollY();
//屏幕高度
int screenHeight = getContext().getResources().getDisplayMetrics().heightPixels;
//有效滑动距离为屏幕2分之一
// alpha = 滑动高度/（screenHeight/3f）
if (scrollY <= screenHeight / 2f) {
Log.d(">>>>>>>>>", "ScrollView划出高度：" + scrollY);
Log.d(">>>>>>>>>", "屏幕高度：" + screenHeight);
Log.d(">>>>>>>>>", "渐变值：" + (0 + scrollY / (screenHeight / 4f)));
// 渐变的过程 1~0
mTranslucentListener.onTranslucent(0 + scrollY / (screenHeight /4f));
}
}
}
}
Activity 设置
public class ToolbarActivity extends AppCompatActivity implements TranslucentListener {
private Toolbar mToolBar;
private MyScrollView mScrollView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_toobar);
mToolBar = findViewById(R.id.id_toolbar);
mScrollView = findViewById(R.id.id_scrollView);
//初始化渐变为0
mToolBar.setAlpha(0);
//设置渐变回调
mScrollView.setTranslucentListener(this);
}
@Override
public void onTranslucent(float alpha) {
mToolBar.setAlpha(alpha);
}
}
渐变回调接口
/**
* @ClassName TranslucentListener
* @Author rex
* @Date 2021/1/27 17:38
*/
public interface TranslucentListener {
/**
* 透明度的回调监听
*
* @param alpha 0~1 透明度
*/
public void onTranslucent(float alpha);
}
布局文件
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.rex.rxhttpdemo.MyScrollView
android:id="@+id/id_scrollView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipChildren="false"
android:clipToPadding="false"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button0" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button1" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button2" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button3" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button4" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button5" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button5" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button5" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button5" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button5" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button5" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button5" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button5" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button" />
<Button
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Button" />
</LinearLayout>
</com.rex.rxhttpdemo.MyScrollView>
<androidx.appcompat.widget.Toolbar
android:id="@+id/id_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorAccent"
app:title="title"
/>
</RelativeLayout>
下滑显示上滑渐变消失
/**
* @ClassName MyScrollView
* @Author Rex
* @Date 2021/1/27 17:38
*/
public class MyScrollView extends ScrollView {
private TranslucentListener mTranslucentListener;
public void setTranslucentListener(TranslucentListener translucentListener) {
this.mTranslucentListener = translucentListener;
}
public MyScrollView(Context context) {
this(context, null);
}
public MyScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
this(context, attrs, defStyleAttr, 0);
}
public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
if (mTranslucentListener != null) {
//ScrollView滑出高度
int scrollY = getScrollY();
//屏幕高度
int screenHeight = getContext().getResources().getDisplayMetrics().heightPixels;
//有效滑动距离为屏幕2分之一
// alpha = 滑动高度/（screenHeight/3f）
if (scrollY <= screenHeight / 2f) {
Log.d(">>>>>>>>>", "ScrollView划出高度：" + scrollY);
Log.d(">>>>>>>>>", "屏幕高度：" + screenHeight);
Log.d(">>>>>>>>>", "渐变值：" + (1 - scrollY / (screenHeight / 4f)));
// 渐变的过程 1~0
mTranslucentListener.onTranslucent(1 - scrollY / (screenHeight /4f));
}
}
}
}
注意: 这里只是更改了 mTranslucentListener.onTranslucent 里的 渐变值
Activty 里 把初始化 mToolBar.setAlpha(0); 去掉
XML
<com.rex.rxhttpdemo.MyScrollView android:id="@+id/id_scrollView" android:layout_width="match_parent" android:layout_height="match_parent" android:clipChildren="false" android:clipToPadding="false" android:paddingTop="?attr/actionBarSize" > </com.rex.rxhttpdemo.MyScrollView>
xml 加入 paddingtop .
注意:
android:clipChildren=“false”
android:clipToPadding="false"
这俩个属性 如果不加会有留白
到此这篇关于Android 滑动Scrollview标题栏渐变效果(仿京东toolbar)的文章就介绍到这了,更多相关Android 滑动Scrollview标题栏渐变内容请搜索海外IDC网以前的文章或继续浏览下面的相关文章希望大家以后多多支持海外IDC网！
【文章转自：韩国cn2服务器 转载请保留连接】