Android应用源码之9.Activity高级学习.zip项目安卓应用源码下载

package com.szy.activity; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; public class MainActivity extends Activity { private final static String TAG="MainActivity"; private static final String CONTENT = "content"; private Button secondBtn=null; private EditText txt = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); txt=(EditText)findViewById(R.id.txt); if (null!=savedInstanceState&&savedInstanceState.containsKey(CONTENT)) { txt.setText(savedInstanceState.getString(CONTENT)); } secondBtn=(Button)findViewById(R.id.secondBtn); secondBtn.setOnClickListener(listener); Log.i(TAG, "MainActivity-->onCreate"); } @Override protected void onDestroy() { super.onDestroy(); Log.i(TAG, "MainActivity-->onDestroy"); } @Override protected void onPause() { super.onPause(); Log.i(TAG, "MainActivity-->onPause"); } @Override protected void onRestart() { super.onRestart(); Log.i(TAG, "MainActivity-->onRestart"); } @Override protected void onResume() { super.onResume(); Log.i(TAG, "MainActivity-->onResume"); } @Override protected void onStart() { super.onStart(); Log.i(TAG, "MainActivity-->onStart"); } @Override protected void onStop() { super.onStop(); Log.i(TAG, "MainActivity-->onStop"); } @Override protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); Log.i(TAG, "MainActivity-->onSaveInstanceState"); String content=txt.getText().toString(); outState.putString(CONTENT, content); } private OnClickListener listener=new OnClickListener() { @Override public void onClick(View v) { Button btn=(Button)v; Intent intent=new Intent(); switch (btn.getId()) { case R.id.secondBtn: intent.setClass(MainActivity.this, SecondActivity.class); break; } startActivity(intent); } }; }