今天有闲情逸致,再来一篇
1.contents填充图片时,如果加圆角,图片会超出圆角框,即还是直角,得加一句masksToBounds(imageView加圆角则没有这样的问题):
layer.masksToBounds = YES;
2.transform.rotation旋转,直接setValue forKeyPath:
摘自文档:
You can not specify a structure field key path using Objective-C 2.0 properties. This will not work:
myLayer.transform.rotation.x=0;
Instead you must use setValue:forKeyPath: or valueForKeyPath: as shown below:
[myLayer setValue:[NSNumber numberWithInt:0] forKeyPath:@"transform.rotation.x"];
注意:当设置y坐标时,直接赋值会有问题,应该先hold住当前状态,再改变(x/z则没问题),我这用的UISlider测试:
CALayer *layer=[window.layer.sublayers objectAtIndex:0];
//hold住当前状态
layer.transform = CATransform3DIdentity;
//用slider来改变,如果没hold住,当大于90度时,慢慢划动会导致一正一反反复出现…
[layer setValue:[NSNumber numberWithFloat:DegreesToRadians(slider.value)] forKeyPath:@"transform.rotation.y"];
3.进一步,摘自文档:
Modifying a Transform Using Key Paths
Core Animation extends the key-value coding protocol to allow getting and setting of the common values of a layer's CATransform3D matrix through key paths. Table 4 describes the key paths for which a layer’s transform and sublayerTransform properties are key-value coding and observing compliant.
Table 4 CATransform3D key paths
Field Key Path
Description
rotation.x
The rotation, in radians, in the x axis.
rotation.y
The rotation, in radians, in the y axis.
rotation.z
The rotation, in radians, in the z axis.
rotation
The rotation, in radians, in the z axis. This is identical to setting the rotation.z field.
scale.x
Scale factor for the x axis.
scale.y
Scale factor for the y axis.
scale.z
Scale factor for the z axis.
scale
Average of all three scale factors.
translation.x
Translate in the x axis.
translation.y
Translate in the y axis.
translation.z
Translate in the z axis.
translation
Translate in the x and y axis. Value is an NSSize or CGSize.
(1)setValue的时候这些keyPath需加前缀transform,如transform.rotation, transform.scale,不然不反应
(2)scale在改变时,x/y同时变,二维z不变,最好也hold,slider的min值最好不要为0(或者检测到0的时候特殊处理),因为scale 0的话会导致layer不见了,那之后的改变都不可见:
slider.minimumValue=0.0;
slider.maximumValue=2.0;
slider.value=1.0;
//scale,出现0值需特殊处理
if(slider.value<0.001){
layer.hidden=YES;
return;
}else{
layer.hidden=NO;
}
layer.transform = CATransform3DIdentity;
[layer setValue:[NSNumber numberWithFloat:slider.value] forKeyPath:@"transform.scale"];
(3)transform.rotation是默认改变的z,而不是三个坐标一起变
(4)transform.translation是改变位置,x为正向右移,y为正向下移(和二维坐标一致),二维时z无变化
修正:并非无变化(google:iphone transform.translation.z
找到http://stackoverflow.com/questions/4150105/my-calayer-is-not-appearing 有一句有用:.m34 is for z-axis transforms)
这样的话,加入下面这句就可以改变Z坐标:
CATransform3D transform = CATransform3DIdentity;
transform.m34 = 1.0 / -100;
layer.transform = transform;
加上setValue,Z改变量随m34的值变化而不同,暂时不知道m34和translation.z的关系…
[layer setValue:[NSNumber numberWithFloat:slider.value] forKeyPath:@"transform.translation.z"];
无线路由设备（Wi-Fi Router）一般有两种用法：作为无线接入设备（工作在AP模式下）或者作为无线路由设备（工作在路由模式下）。作为无线路由时设备就相当于工作在AP 模式下同时提供了路由功能。事实上Wi-Fi设备和Ethernet设备的区别仅仅在第一层和第二层，也就是物理层和数据链路层，在网络连接层就使用的都是相同的IP协议。
可以看出设备工作在AP模式下，参与的仅仅是第一层和第二层；而当其工作在路由模式下时除了作为AP要参与的最下面两层，还要负责路由功能所在的第三层。
这就是这两种工作模式的主要区别。其实用有线网络来类比的话，就是仅仅工作在AP模式下的无线路由相当于有线网络中的交换机，而工作在路由（Router）模式下的无线路由相当于有线网中的路由器。
http://hi.baidu.com/chenbf/blog/item/d0ce2e96d7a01b7654fb963a.html
1.操作权限
<!-- SD卡写入 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.DELETE_CACHE_FILES" />
2.获取文件保存路径
// 获取保存路径
public File getFilePath() {
File filePath = null;
//判断SD卡存在与否
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
filePath = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+ "/A_Test/test/");
if (!filePath.isDirectory()) {//判断文件存在与否，不存在就创建
filePath.mkdirs();
}
} else {
Toast.makeText(Main.this, "存储卡不存在，请插入卡!", 3000).show();
}
return filePath;
}
3.获取图片保存路径
// 获得SD的路径
public String getSDPath() {
File sdPath = null;
if (Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED)) { // sd卡存在
sdPath = new File(Environment.getExternalStorageDirectory()
.getAbsolutePath()
+ File.separator + "mobileoa" + File.separator + "photo");// 获得路径
// sdPath = new File(Environment.getExternalStorageDirectory()
// .getAbsolutePath());// 获得根路径
}
return sdPath != null ? sdPath.toString() : "内存卡不存在！";
}
// 获得SDCard下图片的路径
private List<String> getSDCard() {
imagePaths = new ArrayList<String>();
try {
File file = new File(getSDPath());
File[] files = file.listFiles();
for (File theFile : files) {
if (isImageFile(theFile.getPath())) {
imagePaths.add(theFile.getPath());
}
}
} catch (Exception e) {
return imagePaths;
}
return imagePaths;
}
// 判断是否是图片文件
private boolean isImageFile(String fileName) {
String extension = fileName.substring(fileName.lastIndexOf(".") + 1,
fileName.length()).toLowerCase();
if (extension.equals("jpg") || extension.equals("png")
|| extension.equals("gif") || extension.equals("jpeg")
|| extension.equals("bmp")) {
return true;
}
return false;
}