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
values-19
values-V21
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:[email protected] */ 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
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:[email protected] */ 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脚本之家网站的支持！