Android沉浸式状态栏 + actionBar渐变 + scrollView顶部伸缩效果

闲话不多说，直接上图。

给大家讲讲我的编程思想吧。

第一部分：沉浸式状态栏（API-Level 19, Android4.4 KitKat 之后加入的东西），而且在Api-Level 21版本中新增了一个属性（下面会说到）。所以，style文件应该声明三份。

values

<style name="TranslucentTheme" parent="@style/AppTheme">
</style>

values-19

<style name="TranslucentTheme" parent="@style/AppTheme">
 <item name="android:windowTranslucentStatus">true</item>
 <item name="android:windowTranslucentNavigation">false</item>
</style>

values-V21

<style name="TranslucentTheme" parent="@style/AppTheme">
 <item name="android:windowTranslucentStatus">true</item>
 <item name="android:windowTranslucentNavigation">false</item>
 <!-- v-21 中新增的属性 -->
 <item name="android:statusBarColor">@android:color/transparent</item>
</style>

至于以上属性的含义及使用方式，就不多做解释了。详细可参见 //www.jb51.net/article/104485.htm

第二部分：actionBar渐变

因为要实现actionBar渐变，所以我没有使用系统的actionBar。而是自定义了一个继承自LinearLayout的ViewGroup。

直接给各位看代码

package test.com.widget;
import android.content.Context;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
import test.com.R;
import test.com.impl.ActionBarClickListener;
/**
 * 支持渐变的 actionBar
 * Created by 晖仔(Milo) on 2016/12/28.
 * email:303767416@qq.com
 */
public final class TranslucentActionBar extends LinearLayout {
 private View layRoot;
 private View vStatusBar;
 private View layLeft;
 private View layRight;
 public TextView tvTitle;
 private TextView tvLeft;
 private TextView tvRight;
 private View iconLeft;
 private View iconRight;
 public TranslucentActionBar(Context context) {
  this(context, null);
 }
 public TranslucentActionBar(Context context, AttributeSet attrs) {
  super(context, attrs);
  init();
 }
 public TranslucentActionBar(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
 }
 private void init() {
  setOrientation(HORIZONTAL);
  View contentView = inflate(getContext(), R.layout.actionbar_trans, this);
  layRoot = contentView.findViewById(R.id.lay_transroot);
  vStatusBar = contentView.findViewById(R.id.v_statusbar);
  tvTitle = (TextView) contentView.findViewById(R.id.tv_actionbar_title);
  tvLeft = (TextView) contentView.findViewById(R.id.tv_actionbar_left);
  tvRight = (TextView) contentView.findViewById(R.id.tv_actionbar_right);
  iconLeft = contentView.findViewById(R.id.iv_actionbar_left);
  iconRight = contentView.findViewById(R.id.v_actionbar_right);
 }
 /**
  * 设置状态栏高度
  *
  * @param statusBarHeight
  */
 public void setStatusBarHeight(int statusBarHeight) {
  ViewGroup.LayoutParams params = vStatusBar.getLayoutParams();
  params.height = statusBarHeight;
  vStatusBar.setLayoutParams(params);
 }
 /**
  * 设置是否需要渐变
  */
 public void setNeedTranslucent() {
  setNeedTranslucent(true, false);
 }
 /**
  * 设置是否需要渐变,并且隐藏标题
  *
  * @param translucent
  */
 public void setNeedTranslucent(boolean translucent, boolean titleInitVisibile) {
  if (translucent) {
   layRoot.setBackgroundDrawable(null);
  }
  if (!titleInitVisibile) {
   tvTitle.setVisibility(View.GONE);
  }
 }
 /**
  * 设置标题
  *
  * @param strTitle
  */
 public void setTitle(String strTitle) {
  if (!TextUtils.isEmpty(strTitle)) {
   tvTitle.setText(strTitle);
  } else {
   tvTitle.setVisibility(View.GONE);
  }
 }
 /**
  * 设置数据
  *
  * @param strTitle
  * @param resIdLeft
  * @param strLeft
  * @param resIdRight
  * @param strRight
  * @param listener
  */
 public void setData(String strTitle, int resIdLeft, String strLeft, int resIdRight, String strRight, final ActionBarClickListener listener) {
  if (!TextUtils.isEmpty(strTitle)) {
   tvTitle.setText(strTitle);
  } else {
   tvTitle.setVisibility(View.GONE);
  }
  if (!TextUtils.isEmpty(strLeft)) {
   tvLeft.setText(strLeft);
   tvLeft.setVisibility(View.VISIBLE);
  } else {
   tvLeft.setVisibility(View.GONE);
  }
  if (!TextUtils.isEmpty(strRight)) {
   tvRight.setText(strRight);
   tvRight.setVisibility(View.VISIBLE);
  } else {
   tvRight.setVisibility(View.GONE);
  }
  if (resIdLeft == 0) {
   iconLeft.setVisibility(View.GONE);
  } else {
   iconLeft.setBackgroundResource(resIdLeft);
   iconLeft.setVisibility(View.VISIBLE);
  }
  if (resIdRight == 0) {
   iconRight.setVisibility(View.GONE);
  } else {
   iconRight.setBackgroundResource(resIdRight);
   iconRight.setVisibility(View.VISIBLE);
  }
  if (listener != null) {
   layLeft = findViewById(R.id.lay_actionbar_left);
   layRight = findViewById(R.id.lay_actionbar_right);
   layLeft.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
     listener.onLeftClick();
    }
   });
   layRight.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
     listener.onRightClick();
    }
   });
  }
 }
} 

下面是actionbar_trans.xml的代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:id="@+id/lay_transroot"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:background="@color/colorPrimary"
 android:orientation="vertical">
 <View
  android:id="@+id/v_statusbar"
  android:layout_width="match_parent"
  android:layout_height="1.0dp" />
 <RelativeLayout
  android:layout_width="match_parent"
  android:layout_height="45dp"
  android:orientation="vertical">
  <RelativeLayout
   android:id="@+id/lay_actionbar_left"
   android:layout_width="100dp"
   android:layout_height="match_parent"
   android:orientation="horizontal">
   <ImageView
    android:id="@+id/iv_actionbar_left"
    android:layout_width="20dp"
    android:layout_height="20dp"
    android:layout_centerVertical="true"
    android:layout_marginLeft="10dp"
    android:background="@mipmap/ic_left_light"
    android:visibility="gone" />
   <TextView
    android:id="@+id/tv_actionbar_left"
    style="@style/text_white"
    android:layout_height="match_parent"
    android:layout_marginLeft="10dp"
    android:layout_toRightOf="@+id/iv_actionbar_left"
    android:gravity="center_vertical"
    android:maxLength="2"
    android:singleLine="true"
    android:text="返回"
    android:visibility="gone" />
  </RelativeLayout>
  <TextView
   android:id="@+id/tv_actionbar_title"
   style="@style/text_white"
   android:layout_centerInParent="true"
   android:text="标题"
   android:textSize="16sp" />
  <RelativeLayout
   android:id="@+id/lay_actionbar_right"
   android:layout_width="100dp"
   android:layout_height="match_parent"
   android:layout_alignParentRight="true"
   android:gravity="right"
   android:orientation="horizontal">
   <View
    android:id="@+id/v_actionbar_right"
    android:layout_width="20dp"
    android:layout_height="20dp"
    android:layout_alignParentRight="true"
    android:layout_centerVertical="true"
    android:layout_marginRight="10dp"
    android:visibility="gone" />
   <TextView
    android:id="@+id/tv_actionbar_right"
    style="@style/text_white"
    android:layout_height="match_parent"
    android:layout_marginRight="10dp"
    android:layout_toLeftOf="@+id/v_actionbar_right"
    android:gravity="center_vertical|right"
    android:singleLine="true"
    android:visibility="gone" />
  </RelativeLayout>
 </RelativeLayout>
</LinearLayout> 

这里我即没有用到 android:fitsSystemWindows="true" 属性，也没有用到 StatusBarUtils ，因为我发现使用的时候很容易造成兼容问题。

所以，我的做法是声明了一个高度为0.0dp的 statusbar，背景为透明，然后获取状态栏高度并赋值到它上，来实现兼容。事实证明，这样做的兼容效果最好。

获取状态栏高度代码：

/**
 * 获取状态栏高度
 *
 * @return
 */
public int getStatusBarHeight() {
 //获取status_bar_height资源的ID
 int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
 if (resourceId > 0) {
  //根据资源ID获取响应的尺寸值
  return getResources().getDimensionPixelSize(resourceId);
 }
 return 0;
} 

设置 statusbar高度：

/**
 * 设置状态栏高度
 *
 * @param statusBarHeight
 */
public void setStatusBarHeight(int statusBarHeight) {
 ViewGroup.LayoutParams params = vStatusBar.getLayoutParams();
 params.height = statusBarHeight;
 vStatusBar.setLayoutParams(params);
} 

开启渐变：

/**
 * 设置是否需要渐变
 */
 public void setNeedTranslucent() {
  setNeedTranslucent(true, false);
 }
 /**
 * 设置是否需要渐变,并且隐藏标题
 *
 * @param translucent
 */
 public void setNeedTranslucent(boolean translucent, boolean titleInitVisibile) {
  if (translucent) {
   layRoot.setBackgroundDrawable(null);
  }
  if (!titleInitVisibile) {
   tvTitle.setVisibility(View.GONE);
  }
 } 

第三步：实现ScrollView顶部伸缩

到了这里，必须得说一下，因为是个人项目中用到，所以并没有把功能做的很强大，本人都是以最简单、有效的方式实现的。所以，代码并不像gitHub上那些被下载很多次的开源项目一样，有很高的扩展性。
时间关系，我直接贴代码吧，代码里我都写了注释的。

package test.com.widget;
 import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.graphics.Color;
import android.support.annotation.ColorInt;
import android.support.v4.graphics.ColorUtils;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.ScrollView;
import test.com.R;
import test.com.utils.SizeUtils;
/**
 * Created by 晖仔(Milo) on 2017/2/13.
 * email:303767416@qq.com
 */
public class TranslucentScrollView extends ScrollView {
 static final String TAG = "TranslucentScrollView";
 //伸缩视图
 private View zoomView;
 //伸缩视图初始高度
 private int zoomViewInitHeight = 0;
 // 记录首次按下位置
 private float mFirstPosition = 0;
 // 是否正在放大
 private Boolean mScaling = false;
 //渐变的视图
 private View transView;
 //渐变颜色
 private int transColor = Color.WHITE;
 //渐变开始位置
 private int transStartY = 50;
 //渐变结束位置
 private int transEndY = 300;
 //渐变开始默认位置，Y轴，50dp
 private final int DFT_TRANSSTARTY = 50;
 //渐变结束默认位置，Y轴，300dp
 private final int DFT_TRANSENDY = 300;
 private TranslucentScrollView.TranslucentChangedListener translucentChangedListener;
 public interface TranslucentChangedListener {
  /**
   * 透明度变化，取值范围0-255
   *
   * @param transAlpha
   */
  void onTranslucentChanged(int transAlpha);
 }
 public TranslucentScrollView(Context context) {
  super(context);
 }
 public TranslucentScrollView(Context context, AttributeSet attrs) {
  super(context, attrs);
 }
 public TranslucentScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
 }
 public void setTranslucentChangedListener(TranslucentScrollView.TranslucentChangedListener translucentChangedListener) {
  this.translucentChangedListener = translucentChangedListener;
 }
 /**
  * 设置伸缩视图
  *
  * @param zoomView
  */
 public void setPullZoomView(View zoomView) {
  this.zoomView = zoomView;
  zoomViewInitHeight = zoomView.getLayoutParams().height;
  if (zoomViewInitHeight == LayoutParams.MATCH_PARENT || zoomViewInitHeight == WindowManager.LayoutParams.WRAP_CONTENT) {
   zoomView.post(new Runnable() {
    @Override
    public void run() {
     zoomViewInitHeight = TranslucentScrollView.this.zoomView.getHeight();
    }
   });
  }
 }
 /**
  * 设置渐变视图
  *
  * @param transView 渐变的视图
  */
 public void setTransView(View transView) {
  setTransView(transView, getResources().getColor(R.color.colorPrimary), SizeUtils.dip2px(getContext(), DFT_TRANSSTARTY), SizeUtils.dip2px(getContext(), DFT_TRANSENDY));
 }
 /**
  * 设置渐变视图
  *
  * @param transView 渐变的视图
  * @param transColor 渐变颜色
  * @param transEndY 渐变结束位置
  */
 public void setTransView(View transView, @ColorInt int transColor, int transStartY, int transEndY) {
  this.transView = transView;
  //初始视图-透明
  this.transView.setBackgroundColor(ColorUtils.setAlphaComponent(transColor, 0));
  this.transStartY = transStartY;
  this.transEndY = transEndY;
  this.transColor = transColor;
  if (transStartY > transEndY) {
   throw new IllegalArgumentException("transStartY 不得大于 transEndY .. ");
  }
 }
 /**
  * 获取透明度
  *
  * @return
  */
 private int getTransAlpha() {
  float scrollY = getScrollY();
  if (transStartY != 0) {
   if (scrollY <= transStartY) {
    return 0;
   } else if (scrollY >= transEndY) {
    return 255;
   } else {
    return (int) ((scrollY - transStartY) / (transEndY - transStartY) * 255);
   }
  } else {
   if (scrollY >= transEndY) {
    return 255;
   }
   return (int) ((transEndY - scrollY) / transEndY * 255);
  }
 }
 /**
  * 重置ZoomView
  */
 private void resetZoomView() {
  final ViewGroup.LayoutParams lp = zoomView.getLayoutParams();
  final float h = zoomView.getLayoutParams().height;// ZoomView当前高度
  // 设置动画
  ValueAnimator anim = ObjectAnimator.ofFloat(0.0F, 1.0F).setDuration(200);
  anim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
   @Override
   public void onAnimationUpdate(ValueAnimator animation) {
    float cVal = (Float) animation.getAnimatedValue();
    lp.height = (int) (h - (h - zoomViewInitHeight) * cVal);
    zoomView.setLayoutParams(lp);
   }
  });
  anim.start();
 }
 @Override
 protected void onScrollChanged(int l, int t, int oldl, int oldt) {
  super.onScrollChanged(l, t, oldl, oldt);
  int transAlpha = getTransAlpha();
  if (transView != null) {
   Log.d(TAG, "[onScrollChanged .. in ], 透明度 == " + transAlpha);
   transView.setBackgroundColor(ColorUtils.setAlphaComponent(transColor, transAlpha));
  }
  if (translucentChangedListener != null) {
   translucentChangedListener.onTranslucentChanged(transAlpha);
  }
 }
 @Override
 public boolean onTouchEvent(MotionEvent event) {
  if (zoomView != null) {
   ViewGroup.LayoutParams params = zoomView.getLayoutParams();
   switch (event.getAction()) {
    case MotionEvent.ACTION_UP:
     //手指离开后恢复图片
     mScaling = false;
     resetZoomView();
     break;
    case MotionEvent.ACTION_MOVE:
     if (!mScaling) {
      if (getScrollY() == 0) {
       mFirstPosition = event.getY();
      } else {
       break;
      }
     }
     int distance = (int) ((event.getY() - mFirstPosition) * 0.6);
     if (distance < 0) {
      break;
     }
     mScaling = true;
     params.height = zoomViewInitHeight + distance;
     Log.d(TAG, "params.height == " + params.height + ", zoomViewInitHeight == " + zoomViewInitHeight + ", distance == " + distance);
     zoomView.setLayoutParams(params);
     return true;
   }
  }
  return super.onTouchEvent(event);
 }
} 

总结

以上所述是小编给大家介绍的Android沉浸式状态栏 + actionBar渐变 + scrollView顶部伸缩，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对我们网站的支持！