Unknown failure (Failure) Error while Installing APK 安装失败

在manifest根标签添加：>>>>> android：installLocation="preferExternal"

http://www.cnblogs.com/Lefter/archive/2012/03/07/2383962.html 

//7.0以上拍照需要配置以下4行代码
StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
StrictMode.setVmPolicy(builder.build());
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
    builder.detectFileUriExposure();
}