小编Foo*_*ife的帖子

这是我的自定义属性和我正在使用它的类:

[MethodAttribute(new []{new MethodAttributeMembers(), new MethodAttributeMembers()})]
public class JN_Country
{

}

public class MethodAttribute : Attribute
{
    public MethodAttributeMembers[] MethodAttributeMembers { get; set; }

    public MethodAttribute(MethodAttributeMembers[] methodAttributeMemberses)
    {
        MethodAttributeMembers = methodAttributeMemberses;
    }
}

public class MethodAttributeMembers
{
    public string MethodName { get; set; }
    public string Method { get; set; }
    public string MethodTitle { get; set; }
}

语法错误,显示在上面的第一行:

属性参数必须是属性参数类型的常量表达式,typeof表达式或数组创建表达式

为什么会出现此错误？

我一直在努力寻找,但却没有找到任何帮助.我哪里错了？我真的不知道该怎么办.我在下面写了所有细节.我尝试过但没有成功.

尝试创建"TypeNewsController"类型的控制器时发生错误.确保控制器具有无参数的公共构造函数.

 public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            WebApiConfig.Register(GlobalConfiguration.Configuration);
            AreaRegistration.RegisterAllAreas();
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
            Bootstrapper.Run();
        }
    }

我的apicontroller:

public class TypeNewsController : ApiController
    {
        private readonly ITypeNewsService _typeNewsService;

        public TypeNewsController(ITypeNewsService typeNewsService)
        {
            _typeNewsService = typeNewsService;
        }
        [HttpGet]
        public TypeNewsResponse Get([ModelBinder] PageRequest model)
        {
            model = model ?? new PageRequest();
            var output = _typeNewsService.GetTypeNewss().ToList();
            return new TypeNewsResponse
            {
                Page = model.PageIndex,
                Records = model.PageSize,
                Rows = output.ToList(),
                Total = output.Count() / model.PageSize,
            };
        }
    }

错误:

<Error>
<Message>An …

我使用以下代码"ng-class":

 <i class="fa" ng-class="fa-sort-up:tableService.sortState.sortBy==id && tableService.sortState.sortMode=='asc',
                               fa-sort-down:tableService.sortState.sortBy==id && tableService.sortState.sortMode=='desc',
                               fa-sort:tableService.sortState.sortBy!=id"></i>

如何修复此错误:

Error: [$parse:syntax] Syntax Error: Token ':' is an unexpected token at column 11 of the expression [fa-sort-up:tableService.sortState.sortBy==id && tableService.sortState.sortMode=='asc',
fa-sort-down:tableService.sortState.sortBy==id && tableService.sortState.sortMode=='desc',
fa-sort:tableService.sortState.sortBy!=id] starting at [:tableService.sortState.sortBy==id && tableService.sortState.sortMode=='asc',
fa-sort-down:tableService.sortState.sortBy==id && tableService.sortState.sortMode=='desc',
fa-sort:tableService.sortState.sortBy!=id]

如何检查android中的assets文件夹中是否存在文件？

我正在使用 Android Studio，但似乎没有资产文件夹。所以我创建了一个。

我正在使用此代码来加载我的字体：

File pdfFile = null;
try {
    pdfFile = new File(new URI(("file:///android_assets/tahoma.ttf")));
    if (pdfFile.exists())
        Toast.makeText(MainActivity.this,"Exist",Toast.LENGTH_LONG).show();
    else
        Toast.makeText(MainActivity.this,"No Exist",Toast.LENGTH_LONG).show();
} catch (URISyntaxException e) {
    e.printStackTrace();
}

Android Studio 0.5.2 中的项目结构：

root-module
|--.idea
|--app
|----build
|----src
|------main
|--------assets
|----------tahoma.ttf
|--------java
|----------source code here
|--------res
|------AndroidManifest.xml
|----build.gradle

buildl.gradle 文件：

apply plugin: 'android'

android {
    compileSdkVersion 19
    buildToolsVersion '19.1.0'
    sourceSets {
        main {
            assets.srcDirs = ['assets']
        }
    }
    defaultConfig {
        minSdkVersion 11
        targetSdkVersion 17
        versionCode 1
        versionName "1.0"
    }
    buildTypes …

我正在使用带有sqlite的ormlite.但我们得到的错误是:

07-11 12:39:10.680:E/AndroidRuntime(1415):致命异常:主07-11 12:39:10.680:E/AndroidRuntime(1415):进程:com.mmd.testormlite,PID:1415 07-11 12:39:10.680:E/AndroidRuntime(1415):java.lang.IllegalStateException:找不到OpenHelperClass,因为类com.mmd.testormlite.MainActivity的泛型参数都没有扩展OrmLiteSqliteOpenHelper.您应该使用getHelper(Context,Class).07-11 12:39:10.680:E/AndroidRuntime(1415):at com.j256.ormlite.android.apptools.OpenHelperManager.lookupHelperClass(OpenHelperManager.java:273)07-11 12:39:10.680:E/AndroidRuntime( 1415):at com.j256.ormlite.android.apptools.OpenHelperManager.getHelper(OpenHelperManager.java:105)07-11 12:39:10.680:E/AndroidRuntime(1415):at data.DatabaseManager.getHelper(DatabaseManager.java :17)07-11 12:39:10.680:E/AndroidRuntime(1415):at data.Repo.(Repo.java:13)07-11 12:39:10.680:E/AndroidRuntime(1415):at com. mmd.testormlite.MainActivity $ 1.onClick(MainActivity.java:28)07-11 12:39:10.680:E/AndroidRuntime(1415):at android.view.View.performClick(View.java:4438)07-11 12 :39:10.680:E/AndroidRuntime(1415):在android.view.View $ PerformClick.run(View.java:18422)07-11 12:39:10.680:E/AndroidRuntime(1415):在android.os. Handler.handleCallback(Handler.java:733)07-11 12:39:10.680:E/AndroidRuntime(1415):at android.os.Handler.dispatchMessage(Handler.java:95)07-11 12:39:10.680: E/AndroidRuntime(141 5):在android.os.Looper.loop(Looper.java:136)07-11 12:39:10.680:E/AndroidRuntime(1415):在android.app.ActivityThread.main(ActivityThread.java:5017)07 -11 12:39:10.680:E/AndroidRuntime(1415):at java.lang.reflect.Method.invokeNative(Native Method)07-11 12:39:10.680:E/AndroidRuntime(1415):at java.lang. reflect.Method.invoke(Method.java:515)07-11 12:39:10.680:E/AndroidRuntime(1415):at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:779)07 -11 12:39:10.680:E/AndroidRuntime(1415):at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)07-11 12:39:10.680:E/AndroidRuntime(1415): at dalvik.system.NativeStart.main(Native Method)

DatabaseManager类:

public class DatabaseManager<H extends OrmLiteSqliteOpenHelper> {

    private H helper;

    public H getHelper(Context context)
    {
        if(helper == null)
        {
            helper = (H) OpenHelperManager.getHelper(context);//The method getHelper(Context) from the …