dex文件手動加載

 將已經編譯好的.class或者.dex文件放在sdcard中，供一個已安裝的程序動態調用：

首先將.class文件轉換成.dex文件：

package com.dynamic;
public interface IDynamic {
public String helloWorld();
}

package com.dynamic;
public class DynamicTest implements IDynamic {
    @Override
    public String helloWorld() {
        return "Hello World!";
    }
}

將com.dynamic打包成dynamic.jar

將jar包dynamic.jar放到D:\soft\sdk\sdk\platform-tools目錄下，dos命令切換到此目錄下，輸入dx --dex --output=dynamic.dex dynamic.jar,將此目錄下生成的dynamic.dex文件放到sdcard裡面。

[java]
final File optimizedDexOutputPath = new File(Environment.getExternalStorageDirectory().toString()+File.separator +"wftech"+ 
                File.separator+"dex"+File.separator+ "dynamic.dex");//將dynamic.dex放到/mnt/wftech目錄下  
                DexClassLoader cl = new DexClassLoader(optimizedDexOutputPath.getAbsolutePath(), 
                        <STRONG><SPAN style="COLOR: #ff0000">MainActivity.this.getDir("dex", 0).getAbsolutePath()</SPAN></STRONG>,//一定不能寫錯  
                    null, getClassLoader()); 
                Class libProviderClazz = null; 
                try { 
                    libProviderClazz = cl.loadClass("com.dynamic.DynamicTest"); 
                    IDynamic lib = (IDynamic)libProviderClazz.newInstance(); 
                    Toast.makeText(MainActivity.this, lib.helloWorld(), Toast.LENGTH_SHORT).show(); 
                } catch (Exception exception) { 
                    exception.printStackTrace(); 
                } 

final File optimizedDexOutputPath = new File(Environment.getExternalStorageDirectory().toString()+File.separator +"wftech"+
             File.separator+"dex"+File.separator+ "dynamic.dex");//將dynamic.dex放到/mnt/wftech目錄下
             DexClassLoader cl = new DexClassLoader(optimizedDexOutputPath.getAbsolutePath(),
               MainActivity.this.getDir("dex", 0).getAbsolutePath(),//一定不能寫錯
     null, getClassLoader());
                Class libProviderClazz = null;
                try {
                 libProviderClazz = cl.loadClass("com.dynamic.DynamicTest");
                 IDynamic lib = (IDynamic)libProviderClazz.newInstance();
                 Toast.makeText(MainActivity.this, lib.helloWorld(), Toast.LENGTH_SHORT).show();
                } catch (Exception exception) {
                    exception.printStackTrace();
                }