1、新建一个Activity，并把各个生命周期打印出来
2、运行Activity，得到如下信息
onCreate-->
onStart-->
onResume-->
3、按crtl+f12切换成横屏时
onSaveInstanceState-->
onPause-->
onStop-->
onDestroy-->
onCreate-->
onStart-->
onRestoreInstanceState-->
onResume-->
4、再按crtl+f12切换成竖屏时，发现打印了两次相同的log
onSaveInstanceState-->
onPause-->
onStop-->
onDestroy-->
onCreate-->
onStart-->
onRestoreInstanceState-->
onResume-->
onSaveInstanceState-->
onPause-->
onStop-->
onDestroy-->
onCreate-->
onStart-->
onRestoreInstanceState-->
onResume-->
5、修改AndroidManifest.xml，把该Activity添加 android:configChanges="orientation"，执行步骤3
onSaveInstanceState-->
onPause-->
onStop-->
onDestroy-->
onCreate-->
onStart-->
onRestoreInstanceState-->
onResume-->
6、再执行步骤4，发现不会再打印相同信息，但多打印了一行onConfigChanged
onSaveInstanceState-->
onPause-->
onStop-->
onDestroy-->
onCreate-->
onStart-->
onRestoreInstanceState-->
onResume-->
onConfigurationChanged-->
7、把步骤5的android:configChanges="orientation" 改成 android:configChanges="orientation|keyboardHidden"，执行步骤3，就只打印onConfigChanged
onConfigurationChanged-->
8、执行步骤4
onConfigurationChanged-->
onConfigurationChanged-->
总结：
1、不设置Activity的android:configChanges时，切屏会重新调用各个生命周期，切横屏时会执行一次，切竖屏时会执行两次
2、设置Activity的android:configChanges="orientation"时，切屏还是会重新调用各个生命周期，切横、竖屏时只会执行一次
3、设置Activity的android:configChanges="orientation|keyboardHidden"时，切屏不会重新调用各个生命周期，只会执行onConfigurationChanged方法
总结一下整个Activity的生命周期
补充一点，当前Activity产生事件弹出Toast和AlertDialog的时候Activity的生命周期不会有改变
Activity运行时按下HOME键(跟被完全覆盖是一样的)：onSaveInstanceState --> onPause --> onStop onRestart -->onStart--->onResume
Activity未被完全覆盖只是失去焦点：onPause--->onResume
1 这是实现的adapter类
package com.hao.test;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class gridadapter extends BaseAdapter {
private LayoutInflater inflater;
String[] name;
int[] iconarray;
public gridadapter(Context context, String[] name, int[] iconarray) {
this.inflater = LayoutInflater.from(context);
this.name = name;
this.iconarray = iconarray;
}
@Override
public int getCount() {
return name.length;
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView==null) {
holder=new ViewHolder();
convertView=this.inflater.inflate(R.layout.main_grid_item, null);
holder.iv=(ImageView) convertView.findViewById(R.id.main_grid_item_iv);
holder.tv=(TextView) convertView.findViewById(R.id.main_grid_item_tv);
convertView.setTag(holder);
}
else {
holder=(ViewHolder) convertView.getTag();
}
holder.iv.setImageResource(iconarray[position]);
holder.tv.setText(name[position]);
return convertView;
}
private class ViewHolder{
ImageView iv;
TextView tv;
}
}
2这是要显示的格式main_grid_item
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:gravity="center"
android:layout_width="wrap_content" android:layout_height="wrap_content">
<ImageView android:id="@+id/main_grid_item_iv"
android:layout_width="69dip" android:layout_height="69dip" />
<TextView android:id="@+id/main_grid_item_tv"
android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center_horizontal"
android:text android:textColor="#333333" />
</LinearLayout>
3 这个是activity中要显示的main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<GridView android:id="@+id/main_menu_grid_view"
android:layout_width="fill_parent" android:layout_height="fill_parent"
android:numColumns="auto_fit" android:padding="10dp"
android:verticalSpacing="20dp" android:horizontalSpacing="10dp"
android:columnWidth="75dp" android:stretchMode="columnWidth"
android:gravity="center" />
</LinearLayout>
4 这个是主activity
package com.hao.test;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
public class Test extends Activity {
public GridView gridView;
String aString = "timu";
private String[] name = {
aString, aString, aString, aString, aString, aString, aString, aString
};
private int[] iconarray = {
R.drawable.icon, R.drawable.icon, R.drawable.icon, R.drawable.icon, R.drawable.icon,
R.drawable.icon, R.drawable.icon, R.drawable.icon
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
init();
}
private void init() {
// TODO Auto-generated method stub
gridView = (GridView) findViewById(R.id.main_menu_grid_view);
gridadapter adapter = new gridadapter(this, name, iconarray);
gridView.setAdapter(adapter);
gridView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// TODO Auto-generated method stub
switch (position) {
case 0:
new AlertDialog.Builder(Test.this)
.setTitle("Question")
.setMessage("0")
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
setResult(RESULT_OK);
finish();
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
}
})
.show();
break;
case 1:
new AlertDialog.Builder(Test.this)
.setTitle("Question")
.setMessage("1")
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
setResult(RESULT_OK);
finish();
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
}
})
.show();
break;
default:
break;
}
}
});
}
}
最近做项目涉及到的知识点:
效果图:
直接贴代码了
public String getAllText(Language show_text_language){
StringBuffer stringBuffer = new StringBuffer();
for (int i = 2; i <23; i++) {
String name = "page_" + i + "_text_" + show_text_language.toString().toLowerCase()
+ "_" + 1;
//stringBuffer.append(getResources().getIdentifier(name, "string", getPackageName())).append("\n");
stringBuffer.append(getResources().getString(getResources().getIdentifier(name, "string", getPackageName())));
stringBuffer.append("\n");
}
String allText = stringBuffer.toString();
return allText;
}