动脑学院-自适应屏幕布局

Posted 2022-12-07 天耀106

1、自定义RelativeLayout布局

package lwl.tianyao.testproject;

import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.View;
import android.widget.RelativeLayout;

public class LwlRelativeLayout extends RelativeLayout 

    private boolean flag = true;

    public LwlRelativeLayout(Context context) 
        super(context);
    

    public LwlRelativeLayout(Context context, AttributeSet attrs) 
        super(context, attrs);
    

    public LwlRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) 
        super(context, attrs, defStyleAttr);
    

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) 
        if (flag) 
            int childCount = this.getChildCount();
            float scaleX = UIUtils.getInstance(getContext()).getHorizontalScalValue();
            float scaleY = UIUtils.getInstance(getContext()).getVerticalScaleValue();
            for (int i = 0; i < childCount; i++) 
                View child = this.getChildAt(i);//每个子控件
                RelativeLayout.LayoutParams layoutParams = (LayoutParams) child.getLayoutParams();
                layoutParams.width = (int) (layoutParams.width * scaleX);
                layoutParams.height = (int) (layoutParams.height * scaleY);

                layoutParams.leftMargin = (int) (layoutParams.leftMargin * scaleX);
                layoutParams.rightMargin = (int) (layoutParams.rightMargin * scaleX);

                layoutParams.topMargin = (int) (layoutParams.topMargin * scaleY);
                layoutParams.bottomMargin = (int) (layoutParams.bottomMargin * scaleY);
            
            flag=false;
        
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) 
        super.onLayout(changed, l, t, r, b);
    

    @Override
    protected void onDraw(Canvas canvas) 
        super.onDraw(canvas);
    

2、UIUtils工具类

package lwl.tianyao.testproject;

import android.content.Context;
import android.util.DisplayMetrics;
import android.view.WindowManager;

import java.lang.reflect.Field;

public class UIUtils 

    Context context;

    //基准尺寸
    public static final float STANDARD_WIDTH=1080F;
    public static final float STANDARD_HEIGHT=1920F;

    private static final String MIDEN_CLASS="com.android.internal.R&dimen";

    //实际设备的分辨率
    public static float displayMetricsWidth;
    public static float displayMetricsHeight;

    //单例
    private static UIUtils instance;

    public static UIUtils getInstance(Context context)
        if(instance ==null)
            instance =new UIUtils(context);
        
        return instance;
    

    private UIUtils(Context context)
        this.context= context;
        WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics displayMetrics = new DisplayMetrics();
        if(this.displayMetricsWidth == 0.0f || this.displayMetricsHeight==0.0f)
            windowManager.getDefaultDisplay().getMetrics(displayMetrics);
            //获取状态框的信息
            int systemBarHight= getSystemBarHeight(context);
            if(displayMetrics.widthPixels>displayMetrics.heightPixels)
                //平板或横屏
                displayMetricsWidth = (float) displayMetrics.heightPixels;
                displayMetricsHeight = (float) displayMetrics.heightPixels-systemBarHight;
            else 
                displayMetricsWidth = (float) displayMetrics.widthPixels;
                displayMetricsHeight =(float) displayMetrics.heightPixels-systemBarHight;
            
        
    

    private int getSystemBarHeight(Context context)
        return getValue(context,MIDEN_CLASS,"system_bar_height",48);
    

    private int getValue(Context context, String attrGroupClass, String system_bar_height, int defValue) 
        try 
            Class e = Class.forName(attrGroupClass);
            Object obj = e.newInstance();
            Field field = e.getField(system_bar_height);
            int x=Integer.parseInt(field.get(obj).toString());
            //x获取的ID转为对应的宽高值
            return context.getResources().getDimensionPixelOffset(x);
        catch (Exception e)
            e.printStackTrace();
            return defValue;
        
    

    //水平缩放比
    public float getHorizontalScalValue()
        return ((float)displayMetricsWidth)/STANDARD_WIDTH;
    

    //vertical缩放比
    public float getVerticalScaleValue()
        return ((float)displayMetricsHeight)/STANDARD_HEIGHT;
    

3、布局文件

<?xml version="1.0" encoding="utf-8"?>
<lwl.tianyao.testproject.LwlRelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/tv_1"
        android:layout_width="1080px"
        android:layout_height="600px"
        android:layout_marginTop="50px"
        android:layout_marginBottom="50px"
        android:layout_marginLeft="40px"
        android:layout_marginRight="40px"
        android:text="Hello World!"
        android:background="#f00"
       />

    <TextView
        android:layout_below="@id/tv_1"
        android:layout_width="800px"
        android:layout_height="300px"
        android:layout_marginTop="50px"
        android:layout_marginBottom="50px"
        android:layout_marginLeft="200px"
        android:layout_marginRight="200px"
        android:text="Hello World!"
        android:background="#f00"
       />

</lwl.tianyao.testproject.LwlRelativeLayout>

4、运行效果

1080*1920:

480*800: