本文实例总结了Android实用编程技巧。分享给大家供大家参考，具体如下：
1.让一个图片透明：
Bitmap buffer = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_4444); buffer.eraseColor(Color.TRANSPARENT);
2.直接发送邮件：
Intent intent = new Intent(Intent.ACTION_SENDTO, Uri .fromParts("mailto", "test@test.com", null));
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent);
3.程序控制屏幕变亮：
WindowManager.LayoutParams lp = getWindow().getAttributes(); lp.screenBrightness = 100 / 100.0f; getWindow().setAttributes(lp);
4.过滤特定文本
Filter filter = myAdapter.getFilter(); filter.filter(mySearchText);
5.scrollView scroll停止事件
setOnScrollListener(new OnScrollListener(){
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub }
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
if(scrollState == 0) Log.i("a", "scrolling stopped..."); } });}
6. 对于特定的程序 发起一个关联供打开
Bitmap bmp = getImageBitmap(jpg); String path = getFilesDir().getAbsolutePath() + "/test.png"; File file = new File(path); FileOutputStream fos = new FileOutputStream(file); bmp.compress( CompressFormat.PNG, 100, fos ); fos.close(); Intent intent = new Intent(); intent.setAction(android .content.Intent.ACTION_VIEW); intent.setDataAndType(Uri .fromFile(new File(path)), "image/png"); startActivity(intent);
对于图片上边的不适用索引格式会出错。
Intent intent = new Intent();
intent.setAction(android .content.Intent.ACTION_VIEW);
File file = new File("/sdcard/test.mp4");
intent.setDataAndType(Uri .fromFile(file), "video/*");
startActivity(intent);
Intent intent = new Intent();
intent.setAction(android .content.Intent.ACTION_VIEW);
File file = new File("/sdcard/test.mp3");
intent.setDataAndType(Uri .fromFile(file), "audio/*");
startActivity(intent);
7.设置文本外观
setTextAppearance(context, android .R.style.TextAppearance_Medium); android :textAppearance="?android :attr/textAppearanceMedium"
8.设置单独的发起模式：
<activity android :name=".ArtistActivity" android :label="Artist" android :launchMode="singleTop"> </activity>
Intent i = new Intent(); i.putExtra(EXTRA_KEY_ARTIST, id); i.setClass(this, ArtistActivity.class); i.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP); startActivity(i);
9.创建一个圆角图片
这个的主要原理其实就是利用遮罩，先创建一个圆角方框 然后将图片放在下面：
Bitmap myCoolBitmap = ... ; int w = myCoolBitmap.getWidth(), h = myCoolBitmap.getHeight(); Bitmap rounder = Bitmap.createBitmap(w,h,Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(rounder); Paint xferPaint = new Paint(Paint.ANTI_ALIAS_FLAG); xferPaint.setColor(Color.RED); canvas.drawRoundRect(new RectF(0,0,w,h), 20.0f, 20.0f, xferPaint); xferPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN)); //然后呢实现 canvas.drawBitmap(myCoolBitmap, 0,0, null); canvas.drawBitmap(rounder, 0, 0, xferPaint);
10.在notification 上的icon上加上数字 给人提示有多少个未读
Notification notification = new Notification (icon, tickerText, when); notification .number = 4;
11.背景渐变：
首先建立文件drawable/shape.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android ="http://schemas.android .com/apk/res/android " android :shape="rectangle">
<gradient android :startColor="#FFFFFFFF" android :endColor="#FFFF0000"
android :angle="270"/>
</shape>
在该文件中设置渐变的开始颜色(startColor)、结束颜色(endColor)和角度(angle)
接着创建一个主题values/style.xml
<?xml version="1.0" encoding="utf-8"?> <resources> <style name="NewTheme" parent="android :Theme"> <item name="android :background">@drawable/shape</item> </style> </resources>
然后在AndroidManifest.xml文件中的application或activity中引入该主题,如:
<activity android :name=".ShapeDemo" android :theme="@style/NewTheme">
该方法同样适用于控件
<?php xml version="1.0" ?> ? <response> <error>1</error> <message>Invalid URL.</message> </response>
12. 储存数据 当你在一个实例中保存静态数据，此示例关闭后 下一个实例想引用 静态数据就会为null，这里呢必须重写applition
public class MyApplication extends Application{
private String thing = null;
public String getThing(){
return thing;
}
public void setThing( String thing ){
this.thing = thing;
}
}
public class MyActivity extends Activity {
private MyApplication app;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
app = ((MyApplication)getApplication());
String thing = app.getThing();
}
}
希望本文所述对大家Android程序设计有所帮助。
