最近开始学习Android开发,遇到MainActivity 访问 fragment_main.xml 中的组件空指针问题,各种查资料,没找到好的完整解决方法,只好自己写一个,Activity生命周期还没深入理解,可能存在问题,请大家见谅!最近学习感觉就像又开始搞web前台了-_-!
package com.example.translatedatabyintent; import java.util.zip.Inflater; import android.support.v7.app.ActionBarActivity; import android.support.v7.app.ActionBar; import android.support.v4.app.Fragment; import android.text.StaticLayout; import android.app.Activity; import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.widget.Button; import android.os.Build; public class MainActivity extends ActionBarActivity { private Button button; private static Fragment fragment; @Override protected void onStart(){ super.onStart(); button = (Button)fragment.getView().findViewById(R.id.button1);//根据id查找到某一视图 //绑定事件 button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub Intent intent = new Intent(MainActivity.this,OtherActivity.class); //意图中传递数据 intent.putExtra("name","张三"); intent.putExtra("age",23); intent.putExtra("address","北京"); //启动意图 startActivity(intent); } }); } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);//加载布局文件 //加载布局 if (savedInstanceState == null) { fragment =new PlaceholderFragment(); getSupportFragmentManager().beginTransaction() .add(R.id.container,fragment).commit(); } //View rootView =Inflater.inflate() } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main,menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button,so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } /** * A placeholder fragment containing a simple view. */ //加载碎片! public static class PlaceholderFragment extends Fragment { public PlaceholderFragment() { } @Override public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment_main,container,false); return rootView; } } }