我们希望可以自定义Toolbar，实现一些特定的功能，android.support.v7.widget.Toolbar正好完成这些工作
首先看一下我们预期的效果图：
先看一下Toolbar的布局
<android.support.design.widget.AppBarLayoutandroid:id="@+id/app_bar_layout"android:layout_width="match_parent"android:layout_height="wrap_content"><android.support.v7.widget.Toolbarandroid:id="@+id/toolbar"android:layout_width="match_parent"android:layout_height="?attr/actionBarSize"app:contentInsetStart="0dp"app:popupTheme="@style/toolbar_action_menu_overflow"android:background="@drawable/title_bar"><TextViewandroid:id="@+id/toolbar_title"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="center"android:singleLine="true"android:textColor="@android:color/white"android:textSize="20sp" /></android.support.v7.widget.Toolbar></android.support.design.widget.AppBarLayout>
这里背景的渐变色可以通过定义如下xml来实现，同时将Toolbar的background设置为该xml
<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="/apk/res/android"android:shape="rectangle"><gradientandroid:angle="135"android:endColor="#508eff"android:centerColor="#35b1fd"android:startColor="#65ccff"android:type="linear" /></shape>
为了使标题可以居中显示，在Toolbar中添加了一个TextView用来显示标题，并且需要在Activity中将原标题隐藏
toolbar = findViewById(R.id.toolbar);setSupportActionBar(toolbar);getSupportActionBar().setDisplayUseLogoEnabled(false);
在DrawerLayout中，我们新建ActionBarDrawerToggle并且传入toolbar，我们希望更改Toolbar的导航按钮图标，注意这个操作必须在setSupportActionBar和addDrawerListener操作之后
Resources resources = MainActivity.this.getResources();Drawable drawable = resources.getDrawable(R.drawable.image);int size = 44;CircleDrawable circleDrawable = new CircleDrawable(drawable, MainActivity.this, size);toolbar.setNavigationIcon(circleDrawable);
CircleDrawable是我自己定义为了绘制原型图标的Drawable
package com.sdu.runningsdu.Utils;import android.content.Context;import android.content.res.Resources;import android.graphics.Bitmap;import android.graphics.BitmapShader;import android.graphics.Canvas;import android.graphics.ColorFilter;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.PixelFormat;import android.graphics.Shader;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;import android.support.annotation.NonNull;import android.support.annotation.Nullable;import android.util.TypedValue;/*** Created by FTDsm on /6/7.*/public class CircleDrawable extends Drawable {private Bitmap bitmap;private BitmapShader bitmapShader;private Paint paint;// 圆心private float cx, cy;// 半径private float radius;public CircleDrawable(Drawable drawable, Context context, int size) {size = dip2px(context, size);drawable = zoomDrawable(drawable, dip2px(context, size), dip2px(context, size));this.bitmap = drawableToBitmap(drawable);bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);paint = new Paint();paint.setAntiAlias(true);paint.setShader(bitmapShader);cx = size / 2;cy = size / 2;radius = size / 2;}@Overridepublic void draw(@NonNull Canvas canvas) {canvas.drawCircle(cx, cy, radius, paint);}/*** 缩放Drawable* */private Drawable zoomDrawable(Drawable drawable, int w, int h) {int width = drawable.getIntrinsicWidth();int height = drawable.getIntrinsicHeight();Bitmap oldbmp = drawableToBitmap(drawable);Matrix matrix = new Matrix();float scaleWidth = ((float) w / width);float scaleHeight = ((float) h / height);matrix.postScale(scaleWidth, scaleHeight);Bitmap newbmp = Bitmap.createBitmap(oldbmp, 0, 0, width, height,matrix, true);return new BitmapDrawable(null, newbmp);}/*** Drawable转Bitmap* */private Bitmap drawableToBitmap(Drawable drawable) {int width = drawable.getIntrinsicWidth();int height = drawable.getIntrinsicHeight();Bitmap.Config config = drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888: Bitmap.Config.RGB_565;Bitmap bitmap = Bitmap.createBitmap(width, height, config);Canvas canvas = new Canvas(bitmap);drawable.setBounds(0, 0, width, height);drawable.draw(canvas);return bitmap;}/*** dp to px* */private int dip2px(Context context, float dipValue) {Resources resources = context.getResources();return (int) TypedValue.applyDimension(PLEX_UNIT_DIP, dipValue, resources.getDisplayMetrics());}public static int dip2px1(Context context, float dpValue) {final float scale = context.getResources().getDisplayMetrics().density;return (int) (dpValue * scale + 0.5f);}private int dip2px2(Context context,float dpValue){float scale=context.getResources().getDisplayMetrics().density;return (int)(dpValue*scale+0.5f);}@Overridepublic void setAlpha(int alpha) {paint.setAlpha(alpha);}@Overridepublic void setColorFilter(@Nullable ColorFilter colorFilter) {paint.setColorFilter(colorFilter);}@Overridepublic int getOpacity() {return PixelFormat.TRANSLUCENT;}}
工具栏右侧的菜单可以通过menu设置，以下代码可以完成menu的初始化和无法同时显示图标和文字的问题
@Overridepublic boolean onCreateOptionsMenu(Menu menu) {getMenuInflater().inflate(R.menu.action_menu, menu);return super.onCreateOptionsMenu(menu);}/*** 解决Toolbar中Menu无法同时显示图标和文字的问题* */@Overridepublic boolean onMenuOpened(int featureId, Menu menu) {if (menu != null) {if (menu.getClass().getSimpleName().equalsIgnoreCase("MenuBuilder")) {try {Method method = menu.getClass().getDeclaredMethod("setOptionalIconsVisible", Boolean.TYPE);method.setAccessible(true);method.invoke(menu, true);} catch (Exception e) {e.printStackTrace();}}}return super.onMenuOpened(featureId, menu);}
溢出菜单可以通过定义style来配置，并且要将其添加到Activity Theme style中
<style name="toolbar_action_menu_overflow" parent="Widget.AppCompat.PopupMenu.Overflow"><!--是否覆盖锚点--><item name="overlapAnchor">false</item><!--弹出层水平方向上的偏移，负值为距离右边的空隙--><item name="android:dropDownHorizontalOffset">-10dp</item><!-- 弹出层垂直方向上的偏移，负则会盖住Toolbar --><item name="android:dropDownVerticalOffset">5dp</item><item name="android:divider">@color/colorPrimaryDark</item><item name="android:dividerHeight">1dp</item><item name="android:textColor">@android:color/white</item><item name="android:popupBackground">#48bbfd</item></style>
弹出菜单可以通过setOnMenuItemClickListener设置点击事件
toolbar.setOnMenuItemClickListener(new Toolbar.OnMenuItemClickListener() {@Overridepublic boolean onMenuItemClick(MenuItem item) {int id = item.getItemId();Intent intent;switch (id) {case R.id.item_create_group:break;case R.id.item_add_friend:break;case R.id.item_scan:break;case R.id.item_help_and_feedback:break;}return true;}});
最后如果Toolbar遮挡了content_main.xml，在其被遮挡的布局设置app:layout_behavior属性即可
app:layout_behavior="@string/appbar_scrolling_view_behavior"
