android自定义splash界面

最新推荐文章于 2024-04-14 18:14:54 发布

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最新推荐文章于 2024-04-14 18:14:54 发布

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文章标签： android splash

本文链接：https://blog.youkuaiyun.com/pangzaifei/article/details/19343843

本文将演示如何在Android应用中实现自定义的启动动画，包括解析JSON数据、加载图片并进行尺寸调整和布局，最终在应用启动时展示美观的动画效果。

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项目中，需要做一个应用开始的过场动画，俗称splash。

抽出来做个demo

效果：

主要代码

package com.example.zidingyiflashview;

import java.io.IOException;
import java.io.InputStream;
import java.util.Vector;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import junit.framework.Assert;
import android.content.Context;
import android.content.pm.PackageManager;
import android.content.res.AssetManager;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.View;

public class FlashView extends View {
	Vector<ImageItem> iis=new Vector<ImageItem>();
	public FlashView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		// TODO Auto-generated constructor stub
		init(context);
	}

	public FlashView(Context context, AttributeSet attrs) {
		super(context, attrs);
		// TODO Auto-generated constructor stub
		init(context);
	}

	public FlashView(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
		init(context);
	}

	private void init(Context context) {
		// TODO Auto-generated method stub
		//1.读json数据，解析json，将解析的值封装到imageItem中。在imageItem中设置值，在imageItem中draw
	
		AssetManager assets = context.getAssets();
		
		String fileName="splash/splash.json";
		try {
			InputStream is = assets.open(fileName);
			int available = is.available();
			byte[] buffer=new byte[available];
			is.read(buffer);
			is.close();
			
			//解析json
		String JStr=	new String(buffer,"UTF-8");
			JSONObject jObject=new JSONObject(JStr);
			JSONArray jsonArray = jObject.getJSONArray("images");
			for(int i=0;null!=jsonArray&&i<jsonArray.length();i++){
				JSONObject jObjectArray = jsonArray.getJSONObject(i);
				ImageItem ii = ImageItem.parseImageItem(jObjectArray);
				iis.add(ii);
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	@Override
	protected void onDraw(Canvas canvas) {
		// TODO Auto-generated method stub
		super.onDraw(canvas);
		for(int i=0;i<iis.size();i++){
			iis.get(i).onDraw(getContext(),canvas,getWidth(), getHeight(), "assets://splash/");
		}
		
		
	}
	
	
}

package com.example.zidingyiflashview;

import java.io.IOException;
import java.io.InputStream;

import org.json.JSONObject;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;

public class ImageItem {
	/**
	 * 文件名
	 */
	private String name;
	/**
	 * 长、宽
	 */
	private float[] load;
	/**
	 * 居中等
	 */
	private int algin;
	/**
	 * 缩放
	 */
	private float scale;
	
	
	
	public static ImageItem parseImageItem(JSONObject jsonObject){
		ImageItem ii=new ImageItem();
		ii.name=jsonObject.optString("name",null);
		String optString = jsonObject.optString("load",null);
		//将load封装到float[]里面
		ii.load=parseIntArray(optString,4);
		ii.scale = (float)jsonObject.optDouble("scale",0);
		
		
		String strAlign = jsonObject.optString("align", "");
		if("center".equals(strAlign)){
			ii.algin=Align.CENTER;
		}else if("centerX".equals(strAlign)){
			ii.algin=Align.CENTERX;
		}else if("centerY".equals(strAlign)){
			ii.algin=Align.CENTERY;
		}else{
			ii.algin=Align.NONE;
		}
		
		
		if(null==ii.name||"".equals(ii.name)){
			return null;
		}
		
		
		
		
		
		
		return ii;
		
	}



	private static float[] parseIntArray(String optString, int count) {
		// TODO Auto-generated method stub
		try {
			float[] ft=new float[count];
			String[] split = optString.split(",");
			for(int i=0;i<count;i++){
				ft[i]=Float.parseFloat(split[i].trim());
			}
			return ft;
		} catch (Exception e) {
			// TODO Auto-generated catch block
		}
		return null;
			
	
	}
	
	
	public void onDraw(Context context,Canvas canvas,int width,int height,String baseDir){
		
		Bitmap bitmap=getBitMap(context,baseDir);
		
		int w = bitmap.getWidth();
		int h = bitmap.getHeight();
		
		if(null!=load){
			if(w<load[0]||w>load[1]||h<load[2]||h>load[3]){
				return;
			}
		}
		Matrix matrix=new Matrix();
		if(scale==0F){
			//占满空间
			float d1=width*1.0F/w;
			float d2=height*1.0F/h;
			scale=Math.max(d1, d2);
		}
		matrix.setScale(scale, scale);
		
		//移动
		if(algin==Align.CENTER){
			matrix.postTranslate((width-w*scale)/2, (height-h*scale)/2);
			
		}else if(algin==Align.CENTERX){
			matrix.postTranslate((width-w*scale)/2, 0);
		}else if(algin==Align.CENTERY){
			matrix.postTranslate(0, (height-h*scale)/2);
		}
		
		canvas.drawBitmap(bitmap, matrix, null);
		
		
	}


	/**
	 * 获取图片
	 * @param baseDir 
	 * @param context 
	 * @return
	 */
	private Bitmap getBitMap(Context context, String baseDir) {
		// TODO Auto-generated method stub
		try {
			InputStream is = context.getAssets().open((baseDir+name).substring("assets://".length()));
			Bitmap bitMap = BitmapFactory.decodeStream(is);
			is.close();
			return bitMap;
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}
		
		
	
	}
}

demo地址：

http://download.youkuaiyun.com/detail/pangzaifei/6930265