android编程中的琐碎知识点汇总（5）

1.启动程序无需动画

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

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

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

 

3.文字中间加横线效果

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

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

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：

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：

<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。

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);
        }
    }
}