通过资源名称得到资源id

demo地址

主要应用类

package com.example.activitylibrary;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class LibraryActivity extends Activity {
	String msg = "我是来自Jar中的Activity";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(MResource.getIdByName(getApplication(), "layout", "activity_main"));

		TextView mTextView = (TextView) findViewById(MResource.getIdByName(getApplication(), "id", "textView1"));
		mTextView.setText(msg);

		Button mButton = (Button) findViewById(MResource.getIdByName(getApplication(), "id", "button1"));

		mButton.setText(msg);
		mButton.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				Toast.makeText(getApplication(), msg, Toast.LENGTH_SHORT).show();
			}
		});
	}

}

具体工具类

package com.example.activitylibrary;

import android.content.Context;

/**
 * 根据资源的名字获取其ID值
 * @author
 *
 */
public class MResource {
	public static int getIdByName(Context context, String className, String name) {
		String packageName = context.getPackageName();
		Class r = null;
		int id = 0;
		try {
			r = Class.forName(packageName + ".R");

			Class[] classes = r.getClasses();
			Class desireClass = null;

			for (int i = 0; i < classes.length; ++i) {
				if (classes[i].getName().split("\\$")[1].equals(className)) {
					desireClass = classes[i];
					break;
				}
			}

			if (desireClass != null)
				id = desireClass.getField(name).getInt(desireClass);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (SecurityException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} catch (NoSuchFieldException e) {
			e.printStackTrace();
		}

		return id;
	}
}