android编程中的琐碎知识点汇总（5）

1.启动程序无需动画

Java代码


myIntent.setFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);//1.5的应该使用,这样就可以没有动画效果了

getWindow().setWindowAnimations(1)//1.6的应该使用,这不要忘记放在activity

2.SD卡创建目录

Java代码


File wallpaperDirectory = new File("/sdcard/Wallpaper/");

wallpaperDirectory.mkdirs();

File outputFile = new File(wallpaperDirectory, filename);

FileOutputStream fos = new FileOutputStream(outputFile);

注意要添加权限哦

Xml代码


<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

3.文字中间加横线效果

Java代码


priceTV.setText("价格：2.00元");

priceTV.getPaint().setFlags(Paint.STRIKE_THRU_TEXT_FLAG);

4.android中使用事务操作SQLite数据库

Java代码


SQLiteDatabase db = ....;

db.beginTransaction();//开始事务

try {

db.execSQL（"insert into person(name, age) values(?,?)", new Object[]{"张三",

4});

db.execSQL("update person set name=? where personid=?", new Object[]{"李四", 1});

db.setTransactionSuccessful();//调用此方法会在执行到endTransaction()时提交当前事

务，如果不调用此方法会回滚事务

} finally {

db.endTransaction();//由事务的标志决定是提交事务，还是回滚事务

}

db.close();

5. 关于短信类SmsMessage的疑问

Java代码


public void onReceive(Context context, Intent intent) {

// TODO Auto-generated method stub

Log.d(TAG, "--->onReceive ,SMS reach");

Bundle bundle = intent.getExtras();

if (bundle != null) {

Object[] pdus = (Object[]) bundle.get("pdus");

SmsMessage[] messages = new SmsMessage[pdus.length];

for (int i = 0; i < pdus.length; i++) {

messages = SmsMessage.createFromPdu((byte[]) pdus);

}

for (SmsMessage smsMessage : messages) {

from = smsMessage.getDisplayOriginatingAddress();

data = smsMessage.getDisplayMessageBody().trim();

Log.d(TAG, from + " " + data);

//处理内容

response(context, data);

}

}

}

6.android中的WebView支持多点触控：

Java代码


public class UsingMyWebview extends Activity {

private WebView mWebView;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

// Get Web view

mWebView = (WebView) findViewById(R.id.MyWebview);// This is the id you gave to the WebView in the main.xml

mWebView.getSettings().setJavaScriptEnabled(true);

mWebView.getSettings().setSupportZoom(true);

// Zoom Control on web (You don't need this if ROM supports Multi-Touch

mWebView.getSettings().setBuiltInZoomControls(true);// Enable Multitouch if supported by ROM

//Load URL

mWebView.loadUrl("http://www.firstdroid.com/advertisement.htm");

}

}

7.android程序开机自动启动实现：

Xml代码


<receiver android:name=".BootBroadcastReceiver">

<intent-filter>

<action android:name="android.intent.action.BOOT_COMPLETED" />

</intent-filter>

</receiver>

在manifest文件的application标签中添加receiver标签，并且android:name指定一个BroadcastReceiver，通过过滤器实现过滤开机的完成那个广播。

Java代码


package com.jftt.bootstart;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

public class BootBroadcastReceiver extends BroadcastReceiver {

static final String ACTION = "android.intent.action.BOOT_COMPLETED";

@Override

public void onReceive(Context context, Intent intent) {

if (intent.getAction().equals(ACTION)) {

Intent sayHelloIntent = new Intent(context, BootStart.class);//指定要开启的activity页面

sayHelloIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

context.startActivity(sayHelloIntent);

}

}

}