1、引言
底部导航栏在app应用中是十分常见了,大部分的安卓应用中也都实现了底部导航栏的功能,这里我就以我以前做的一个简单小说阅读软件为例,为大家演示一下底部导航栏的使用,需要的朋友直接复制代码过去改写就行了。
2、代码实现
2.1、主界面布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:app="http://schemas.android.com/apk/res-auto"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"tools:context=".MainActivity"><FrameLayoutandroid:id="@+id/fl_content"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_weight="1" /><RadioGroupandroid:id="@+id/rg_main"android:layout_width="match_parent"android:layout_height="wrap_content"android:background="#f5f5f5"android:gravity="center_vertical"android:orientation="horizontal"android:padding="3dp"><!--书架--><com.kotlin.custom.DrawableRadioButtonandroid:id="@+id/rb_main_book"style="@style/bottom_tag_style"android:text="书架"app:drawableSize="30dp"android:clickable="true"app:drawableTop="@drawable/book_drawable_selector" /><!--书城--><com.kotlin.custom.DrawableRadioButtonandroid:id="@+id/rb_main_store"style="@style/bottom_tag_style"android:text="书城"android:clickable="true"app:drawableSize="30dp"app:drawableTop="@drawable/store_drawable_selector" /><!--我的--><com.kotlin.custom.DrawableRadioButtonandroid:id="@+id/rb_main_user"style="@style/bottom_tag_style"android:text="我的"android:clickable="true"app:drawableSize="30dp"app:drawableTop="@drawable/user_drawable_selector" /></RadioGroup>
</LinearLayout>
2.2、主界面代码
这里包含了一些进行操作实际功能的代码,大家复制时直接忽略就行。
package com.kotlin.novel;import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;
import androidx.fragment.app.FragmentTransaction;import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.Gravity;
import android.view.KeyEvent;
import android.view.View;
import android.widget.RadioGroup;
import android.widget.Toast;import com.google.gson.Gson;
import com.kotlin.base.BaseFragment;
import com.kotlin.data.UpdateVersion;
import com.kotlin.dialog.UpdateDialogActivity;
import com.kotlin.fragment.BookShelfFragment;
import com.kotlin.fragment.BookStoreFragment;
import com.kotlin.fragment.UserFragment;
import com.kotlin.utils.ServerUtils;
import com.kotlin.utils.SetUiSize;import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;/*** 主界面导航切换,如果需要添加界面来这里修改*/
public class MainActivity extends FragmentActivity {@Overrideprotected void onResume() {//强制竖屏if (getRequestedOrientation()!=ActivityInfo.SCREEN_ORIENTATION_PORTRAIT){setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);}super.onResume();}public static MainActivity activity;public RadioGroup rg_main;private List<BaseFragment> baseFragment;private int position;//选中的Fragment的对应的位置private Fragment fragment;//上次切换的Fragment@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);View decorView=getWindow().getDecorView();//获取当前界面的DecorViewint option=View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN |View.SYSTEM_UI_FLAG_LAYOUT_STABLE |//全屏隐藏状态栏View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR;//更改文字颜色为深黑色decorView.setSystemUiVisibility(option);//设置系统UI元素的可见性getWindow().setNavigationBarColor(Color.TRANSPARENT);getWindow().setStatusBarColor(Color.TRANSPARENT);//将状态栏设置为透明色rg_main = findViewById(R.id.rg_main);initFragment();setListener();activity=this;updateVersion();}private void setListener() {rg_main.setOnCheckedChangeListener(new CheckedChangeListener());//设置默认选中书架rg_main.check(R.id.rb_main_book);}class CheckedChangeListener implements RadioGroup.OnCheckedChangeListener {@Overridepublic void onCheckedChanged(RadioGroup group, int checkedId) {switch (checkedId){case R.id.rb_main_book://书架position = 0;break;case R.id.rb_main_store://书城position = 1;break;case R.id.rb_main_user://我的position = 2;break;}//根据位置得到对应的FragmentBaseFragment to = getFragment();//替换switchFrament(fragment,to);}}/*** @param from 刚显示的Fragment,马上就要被隐藏* @param to 马上要切换到的Fragment,马上就要被显示*/private void switchFrament(Fragment from,Fragment to) {if(from != to){fragment = to;FragmentTransaction ft = getSupportFragmentManager().beginTransaction();//判断有没有被添加,才切换if(!to.isAdded()){//to没有被添加//from隐藏if(from != null){ft.hide(from);}//添加toif(to != null){ft.add(R.id.fl_content,to).commit();}}else{//to已经被添加// from隐藏if(from != null){ft.hide(from);}//显示toif(to != null){ft.show(to).commit();}}}}/*** 根据位置得到对应的Fragment* @return*/private BaseFragment getFragment() {BaseFragment fragment = baseFragment.get(position);return fragment;}private void initFragment() {baseFragment = new ArrayList<>();baseFragment.add(new BookShelfFragment());//书架FragmentbaseFragment.add(new BookStoreFragment());//书城FragmentbaseFragment.add(new UserFragment());//我的Fragment}public boolean exit;//标识是否可以退出@Overridepublic boolean onKeyUp(int keyCode, KeyEvent event) {if(event.getKeyCode()==KeyEvent.KEYCODE_BACK) {if(exit) {BookShelfFragment.fragment.handler.sendEmptyMessage(1);//刷新书架,取消选择return true;//不退出}}return super.onKeyUp(keyCode, event);}private String result;/*** 获取更新数据*/private void updateVersion(){new Thread(){@Overridepublic void run() {URL url;try {url=new URL(ServerUtils.updatePath);HttpURLConnection connection = (HttpURLConnection) url.openConnection();connection.setReadTimeout(5000);connection.setConnectTimeout(5000);int code = connection.getResponseCode();if (code==200){InputStream is = connection.getInputStream();ByteArrayOutputStream bs=new ByteArrayOutputStream();int len=-1;byte[] buffer=new byte[1024];while ((len=is.read(buffer))!=-1){bs.write(buffer,0,len);}result = bs.toString();bs.close();is.close();connection.disconnect();}} catch (Exception e) {}if (result!=null&&!result.equals("")){handler.sendEmptyMessage(0);}}}.start();}/*** 提示* @param message*/private void tip(String message){runOnUiThread(() -> {//更改默认Toast显示方式,需要什么直接调用方法就行Toast toast=Toast.makeText(MainActivity.this,message,Toast.LENGTH_SHORT);int size= (int) (280/ SetUiSize.displayHeightDp*SetUiSize.displayHeight);toast.setGravity(Gravity.TOP,0,size);toast.show();});}private Handler handler=new Handler(){@Overridepublic void handleMessage(@NonNull Message msg) {super.handleMessage(msg);switch (msg.what){case 0:{UpdateVersion version = new Gson().fromJson(result, UpdateVersion.class);if (version.getApk_version()>ServerUtils.versionCode){Intent intent=new Intent(MainActivity.this, UpdateDialogActivity.class);intent.putExtra("result",result);startActivity(intent);}}break;}}};
}
2.3、自定义控件
自定义radiobutton:
package com.kotlin.custom;import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.RadioButton;import com.kotlin.novel.R;
/*** Describe:可控制drawableTop等图片的大小*/
@SuppressLint("AppCompatCustomView")
public class DrawableRadioButton extends RadioButton {private int mDrawableSize;// xml文件中设置的大小public DrawableRadioButton(Context context) {this(context, null, 0);}public DrawableRadioButton(Context context, AttributeSet attrs) {this(context, attrs, 0);}public DrawableRadioButton(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);Drawable drawableLeft = null, drawableTop = null, drawableRight = null, drawableBottom = null;TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.DrawableRadioButton);int n = a.getIndexCount();for (int i = 0; i < n; i++) {int attr = a.getIndex(i);switch (attr) {case R.styleable.DrawableRadioButton_drawableSize:mDrawableSize = a.getDimensionPixelSize(R.styleable.DrawableRadioButton_drawableSize, 50);break;case R.styleable.DrawableRadioButton_drawableTop:drawableTop = a.getDrawable(attr);break;case R.styleable.DrawableRadioButton_drawableBottom:drawableRight = a.getDrawable(attr);break;case R.styleable.DrawableRadioButton_drawableRight:drawableBottom = a.getDrawable(attr);break;case R.styleable.DrawableRadioButton_drawableLeft:drawableLeft = a.getDrawable(attr);break;}}a.recycle();setCompoundDrawablesWithIntrinsicBounds(drawableLeft, drawableTop, drawableRight, drawableBottom);}/*** RadioButton上、下、左、右设置图标*/public void setCompoundDrawablesWithIntrinsicBounds(Drawable left, Drawable top, Drawable right, Drawable bottom) {if (left != null) {left.setBounds(0, 0, mDrawableSize, mDrawableSize);}if (right != null) {right.setBounds(0, 0, mDrawableSize, mDrawableSize);}if (top != null) {top.setBounds(0, 0, mDrawableSize, mDrawableSize);}if (bottom != null) {bottom.setBounds(0, 0, mDrawableSize, mDrawableSize);}setCompoundDrawables(left, top, right, bottom);}
}
自定义圆形图标。
package com.kotlin.custom;import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.*;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import com.kotlin.novel.R;public class CircleImageView extends androidx.appcompat.widget.AppCompatImageView {private static final ScaleType SCALE_TYPE = ScaleType.CENTER_CROP;private static final Bitmap.Config BITMAP_CONFIG = Bitmap.Config.ARGB_8888;private static final int COLORDRAWABLE_DIMENSION = 1;private static final int DEFAULT_BORDER_WIDTH = 0;private static final int DEFAULT_BORDER_COLOR = Color.BLACK;private final RectF mDrawableRect = new RectF();private final RectF mBorderRect = new RectF();private final Matrix mShaderMatrix = new Matrix();private final Paint mBitmapPaint = new Paint();private final Paint mBorderPaint = new Paint();private int mBorderColor = DEFAULT_BORDER_COLOR;private int mBorderWidth = DEFAULT_BORDER_WIDTH;private Bitmap mBitmap;private BitmapShader mBitmapShader;private int mBitmapWidth;private int mBitmapHeight;private float mDrawableRadius;private float mBorderRadius;private boolean mReady;private boolean mSetupPending;public CircleImageView(Context context) {super(context);}public CircleImageView(Context context, AttributeSet attrs) {this(context, attrs, 0);}public CircleImageView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);super.setScaleType(SCALE_TYPE);TypedArray a = context.obtainStyledAttributes(attrs,R.styleable.CircleImageView, defStyle, 0);mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_border_width, DEFAULT_BORDER_WIDTH);mBorderColor = a.getColor(R.styleable.CircleImageView_border_color,DEFAULT_BORDER_COLOR);a.recycle();mReady = true;if (mSetupPending) {setup();mSetupPending = false;}}@Overridepublic ScaleType getScaleType() {return SCALE_TYPE;}@Overridepublic void setScaleType(ScaleType scaleType) {if (scaleType != SCALE_TYPE) {throw new IllegalArgumentException(String.format("ScaleType %s not supported.", scaleType));}}@Overrideprotected void onDraw(Canvas canvas) {if (getDrawable() == null) {return;}canvas.drawCircle(getWidth() / 2, getHeight() / 2, mDrawableRadius,mBitmapPaint);if (mBorderWidth != 0) {canvas.drawCircle(getWidth() / 2, getHeight() / 2, mBorderRadius,mBorderPaint);}}@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh) {super.onSizeChanged(w, h, oldw, oldh);setup();}public int getBorderColor() {return mBorderColor;}public void setBorderColor(int borderColor) {if (borderColor == mBorderColor) {return;}mBorderColor = borderColor;mBorderPaint.setColor(mBorderColor);invalidate();}public int getBorderWidth() {return mBorderWidth;}public void setBorderWidth(int borderWidth) {if (borderWidth == mBorderWidth) {return;}mBorderWidth = borderWidth;setup();}@Overridepublic void setImageBitmap(Bitmap bm) {super.setImageBitmap(bm);mBitmap = bm;setup();}@Overridepublic void setImageDrawable(Drawable drawable) {super.setImageDrawable(drawable);mBitmap = getBitmapFromDrawable(drawable);setup();}@Overridepublic void setImageResource(int resId) {super.setImageResource(resId);mBitmap = getBitmapFromDrawable(getDrawable());setup();}private Bitmap getBitmapFromDrawable(Drawable drawable) {if (drawable == null) {return null;}if (drawable instanceof BitmapDrawable) {return ((BitmapDrawable) drawable).getBitmap();}try {Bitmap bitmap;if (drawable instanceof ColorDrawable) {bitmap = Bitmap.createBitmap(COLORDRAWABLE_DIMENSION,COLORDRAWABLE_DIMENSION, BITMAP_CONFIG);} else {bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),drawable.getIntrinsicHeight(), BITMAP_CONFIG);}Canvas canvas = new Canvas(bitmap);drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());drawable.draw(canvas);return bitmap;} catch (OutOfMemoryError e) {return null;}}private void setup() {if (!mReady) {mSetupPending = true;return;}if (mBitmap == null) {return;}mBitmapShader = new BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);mBitmapPaint.setAntiAlias(true);mBitmapPaint.setShader(mBitmapShader);mBorderPaint.setStyle(Paint.Style.STROKE);mBorderPaint.setAntiAlias(true);mBorderPaint.setColor(mBorderColor);mBorderPaint.setStrokeWidth(mBorderWidth);mBitmapHeight = mBitmap.getHeight();mBitmapWidth = mBitmap.getWidth();mBorderRect.set(0, 0, getWidth(), getHeight());mBorderRadius = Math.min((mBorderRect.height() - mBorderWidth) / 2,(mBorderRect.width() - mBorderWidth) / 2);mDrawableRect.set(mBorderWidth, mBorderWidth, mBorderRect.width()- mBorderWidth, mBorderRect.height() - mBorderWidth);mDrawableRadius = Math.min(mDrawableRect.height() / 2,mDrawableRect.width() / 2);updateShaderMatrix();invalidate();}private void updateShaderMatrix() {float scale;float dx = 0;float dy = 0;mShaderMatrix.set(null);if (mBitmapWidth * mDrawableRect.height() > mDrawableRect.width()* mBitmapHeight) {scale = mDrawableRect.height() / (float) mBitmapHeight;dx = (mDrawableRect.width() - mBitmapWidth * scale) * 0.5f;} else {scale = mDrawableRect.width() / (float) mBitmapWidth;dy = (mDrawableRect.height() - mBitmapHeight * scale) * 0.5f;}mShaderMatrix.setScale(scale, scale);mShaderMatrix.postTranslate((int) (dx + 0.5f) + mBorderWidth,(int) (dy + 0.5f) + mBorderWidth);mBitmapShader.setLocalMatrix(mShaderMatrix);}
}
自定义控件的attrs文件。
<?xml version="1.0" encoding="utf-8"?>
<resources><!--自定义RadioButton,增加了控制图片的功能,不要在themes文件中也加上,否则会报错--><declare-styleable name="DrawableRadioButton"><attr name="drawableSize" format="dimension"/><attr name="drawableTop" format="reference"/><attr name="drawableLeft" format="reference"/><attr name="drawableRight" format="reference"/><attr name="drawableBottom" format="reference"/></declare-styleable><declare-styleable name="CircleImageView"><attr name="border_width" format="dimension"/><attr name="border_color" format="color" /></declare-styleable>
</resources>
3、效果
3.1、书架页面

3.2、书城页面

3.3、我的页面
