我正在尝试以xamarin形式实现Rich Text框。发生此异常。
未处理的异常：Xamarin.Forms.Xaml.XamlParseException：位置12:21。找不到关键的FromRTFConverter的StaticResource
这是我的xaml代码
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:demoapp"
xmlns:converters="clr-namespace:demoapp"
x:Class="demoapp.MainPage"
>
<StackLayout Orientation="Vertical">
<Label Text="Simple xamarin forms control" TextColor="Red" HorizontalOptions="Center" FontSize="Large"/>
<Entry />
<StackLayout>
<Picker x:Name="pickerDynamicData" Title="Select Country" HorizontalOptions="FillAndExpand" SelectedItem="{Binding Name}" SelectedIndexChanged="PickerSelection" HeightRequest="50" TextColor="Blue"/>
<Editor Text="{Binding CaretNote, Mode=OneWay, Converter={StaticResource FromRTFConverter}}" MinimumWidthRequest="250" HorizontalOptions="Fill" VerticalOptions="StartAndExpand" IsEnabled="False"/>
</StackLayout>
</StackLayout>
</ContentPage>
我尝试遵循this的示例来解决此问题。所以我在XAML代码中进行了更改
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:demoapp"
xmlns:converters="clr-namespace:demoapp"
x:Class="demoapp.MainPage"
>
<ContentPage.Resources>
<ResourceDictionary>
<converters:FromRTFConverter x:Key="FromRTFConverter" />
</ResourceDictionary>
</ContentPage.Resources>
<StackLayout Orientation="Vertical">
<Label Text="Simple xamarin forms control" TextColor="Red" HorizontalOptions="Center" FontSize="Large"/>
<Entry />
<StackLayout>
<Picker x:Name="pickerDynamicData" Title="Select Country" HorizontalOptions="FillAndExpand" SelectedItem="{Binding Name}" SelectedIndexChanged="PickerSelection" HeightRequest="50" TextColor="Blue"/>
<Editor Text="{Binding CaretNote, Mode=OneWay, Converter={StaticResource FromRTFConverter}}" MinimumWidthRequest="250" HorizontalOptions="Fill" VerticalOptions="StartAndExpand" IsEnabled="False"/>
</StackLayout>
</StackLayout>
</ContentPage>
但是我得到了这个异常
未找到类型'converters：FromRTFConverter'。确认您没有丢失程序集引用，并且所有引用的程序集均已构建。
这是我的xaml.cs代码
namespace demoapp
{
public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
ObservableCollection<string> objStringList = new ObservableCollection<string>();
//Mostly below ObservableCollection Items we will get from server but here Iam mentioned static data.
ObservableCollection<PickerItems> objClassList = new ObservableCollection<PickerItems>();
objClassList.Add(new PickerItems { Name = "India" });
objClassList.Add(new PickerItems { Name = "Pakistan" });
objClassList.Add(new PickerItems { Name = "America" });
objClassList.Add(new PickerItems { Name = "London" });
objClassList.Add(new PickerItems { Name = "China" });
/*Here we have to assign service Items to one ObservableCollection<string>() for this purpose
I am using foreach and we can add each item to the ObservableCollection<string>(). */
foreach (var item in objClassList)
{
// Here I am adding each item Name to the ObservableCollection<string>() and below I will assign to the Picker
objStringList.Add(item.Name);
}
//Now I am given ItemsSorce to the Pickers
pickerDynamicData.ItemsSource = objStringList;
}
private void PickerSelection(object sender, EventArgs e)
{
var picker = (Picker)sender;
int selectedIndex = picker.SelectedIndex;
//put your code here
}
private void PickerSelection1(object sender, EventArgs e)
{
var picker = (Picker)sender;
int selectedIndex = picker.SelectedIndex;
//put your code here
}
private class StackEntry
{
public int NumberOfCharactersToSkip { get; set; }
public bool Ignorable { get; set; }
public StackEntry(int numberOfCharactersToSkip, bool ignorable)
{
NumberOfCharactersToSkip = numberOfCharactersToSkip;
Ignorable = ignorable;
}
}
private static readonly Regex _rtfRegex = new Regex(@"\\([a-z]{1,32})(-?\d{1,10})?[ ]?|\\'([0-9a-f]{2})|\\([^a-z])|([{}])|[\r\n]+|(.)", RegexOptions.Singleline | RegexOptions.IgnoreCase);
/// <summary>
/// RTF reserved words
/// </summary>
private static readonly List<string> destinations = new List<string>
{
"aftncn","aftnsep","aftnsepc","annotation","atnauthor","atndate","atnicn","atnid",
"atnparent","atnref","atntime","atrfend","atrfstart","author","background",
"bkmkend","bkmkstart","blipuid","buptim","category","colorschememapping",
"colortbl","comment","company","creatim","datafield","datastore","defchp","defpap",
"do","doccomm","docvar","dptxbxtext","ebcend","ebcstart","factoidname","falt",
"fchars","ffdeftext","ffentrymcr","ffexitmcr","ffformat","ffhelptext","ffl",
"ffname","ffstattext","field","file","filetbl","fldinst","fldrslt","fldtype",
"fname","fontemb","fontfile","fonttbl","footer","footerf","footerl","footerr",
"footnote","formfield","ftncn","ftnsep","ftnsepc","g","generator","gridtbl",
"header","headerf","headerl","headerr","hl","hlfr","hlinkbase","hlloc","hlsrc",
"hsv","htmltag","info","keycode","keywords","latentstyles","lchars","levelnumbers",
"leveltext","lfolevel","linkval","list","listlevel","listname","listoverride",
"listoverridetable","listpicture","liststylename","listtable","listtext",
"lsdlockedexcept","macc","maccPr","mailmerge","maln","malnScr","manager","margPr",
"mbar","mbarPr","mbaseJc","mbegChr","mborderBox","mborderBoxPr","mbox","mboxPr",
"mchr","mcount","mctrlPr","md","mdeg","mdegHide","mden","mdiff","mdPr","me",
"mendChr","meqArr","meqArrPr","mf","mfName","mfPr","mfunc","mfuncPr","mgroupChr",
"mgroupChrPr","mgrow","mhideBot","mhideLeft","mhideRight","mhideTop","mhtmltag",
"mlim","mlimloc","mlimlow","mlimlowPr","mlimupp","mlimuppPr","mm","mmaddfieldname",
"mmath","mmathPict","mmathPr","mmaxdist","mmc","mmcJc","mmconnectstr",
"mmconnectstrdata","mmcPr","mmcs","mmdatasource","mmheadersource","mmmailsubject",
"mmodso","mmodsofilter","mmodsofldmpdata","mmodsomappedname","mmodsoname",
"mmodsorecipdata","mmodsosort","mmodsosrc","mmodsotable","mmodsoudl",
"mmodsoudldata","mmodsouniquetag","mmPr","mmquery","mmr","mnary","mnaryPr",
"mnoBreak","mnum","mobjDist","moMath","moMathPara","moMathParaPr","mopEmu",
"mphant","mphantPr","mplcHide","mpos","mr","mrad","mradPr","mrPr","msepChr",
"mshow","mshp","msPre","msPrePr","msSub","msSubPr","msSubSup","msSubSupPr","msSup",
"msSupPr","mstrikeBLTR","mstrikeH","mstrikeTLBR","mstrikeV","msub","msubHide",
"msup","msupHide","mtransp","mtype","mvertJc","mvfmf","mvfml","mvtof","mvtol",
"mzeroAsc","mzeroDesc","mzeroWid","nesttableprops","nextfile","nonesttables",
"objalias","objclass","objdata","object","objname","objsect","objtime","oldcprops",
"oldpprops","oldsprops","oldtprops","oleclsid","operator","panose","password",
"passwordhash","pgp","pgptbl","picprop","pict","pn","pnseclvl","pntext","pntxta",
"pntxtb","printim","private","propname","protend","protstart","protusertbl","pxe",
"result","revtbl","revtim","rsidtbl","rxe","shp","shpgrp","shpinst",
"shppict","shprslt","shptxt","sn","sp","staticval","stylesheet","subject","sv",
"svb","tc","template","themedata","title","txe","ud","upr","userprops",
"wgrffmtfilter","windowcaption","writereservation","writereservhash","xe","xform",
"xmlattrname","xmlattrvalue","xmlclose","xmlname","xmlnstbl",
"xmlopen"
};
/// <summary>
/// Special characters
/// </summary>
private static readonly Dictionary<string, string> specialCharacters = new Dictionary<string, string>
{
{ "par", "\n" },
{ "sect", "\n\n" },
{ "page", "\n\n" },
{ "line", "\n" },
{ "tab", "\t" },
{ "emdash", "\u2014" },
{ "endash", "\u2013" },
{ "emspace", "\u2003" },
{ "enspace", "\u2002" },
{ "qmspace", "\u2005" },
{ "bullet", "\u2022" },
{ "lquote", "\u2018" },
{ "rquote", "\u2019" },
{ "ldblquote", "\u201C" },
{ "rdblquote", "\u201D" },
};
/// <summary>
/// Strip RTF Tags from RTF Text
/// </summary>
/// <param name="inputRtf">RTF formatted text</param>
/// <returns>Plain text from RTF</returns>
public static string StripRichTextFormat(string inputRtf)
{
if (inputRtf == null)
{
return null;
}
string returnString;
var stack = new Stack<StackEntry>();
bool ignorable = false; // Whether this group (and all inside it) are "ignorable".
int ucskip = 1; // Number of ASCII characters to skip after a unicode character.
int curskip = 0; // Number of ASCII characters left to skip
var outList = new List<string>(); // Output buffer.
MatchCollection matches = _rtfRegex.Matches(inputRtf);
if (matches.Count > 0)
{
foreach (Match match in matches)
{
string word = match.Groups[1].Value;
string arg = match.Groups[2].Value;
string hex = match.Groups[3].Value;
string character = match.Groups[4].Value;
string brace = match.Groups[5].Value;
string tchar = match.Groups[6].Value;
if (!String.IsNullOrEmpty(brace))
{
curskip = 0;
if (brace == "{")
{
// Push state
stack.Push(new StackEntry(ucskip, ignorable));
}
else if (brace == "}")
{
// Pop state
StackEntry entry = stack.Pop();
ucskip = entry.NumberOfCharactersToSkip;
ignorable = entry.Ignorable;
}
}
else if (!String.IsNullOrEmpty(character)) // \x (not a letter)
{
curskip = 0;
if (character == "~")
{
if (!ignorable)
{
outList.Add("\xA0");
}
}
else if ("{}\\".Contains(character))
{
if (!ignorable)
{
outList.Add(character);
}
}
else if (character == "*")
{
ignorable = true;
}
}
else if (!String.IsNullOrEmpty(word)) // \foo
{
curskip = 0;
if (destinations.Contains(word))
{
ignorable = true;
}
else if (ignorable)
{
}
else if (specialCharacters.ContainsKey(word))
{
outList.Add(specialCharacters[word]);
}
else if (word == "uc")
{
ucskip = Int32.Parse(arg);
}
else if (word == "u")
{
int c = Int32.Parse(arg);
if (c < 0)
{
c += 0x10000;
}
outList.Add(Char.ConvertFromUtf32(c));
curskip = ucskip;
}
}
else if (!String.IsNullOrEmpty(hex)) // \'xx
{
if (curskip > 0)
{
curskip -= 1;
}
else if (!ignorable)
{
int c = Int32.Parse(hex, System.Globalization.NumberStyles.HexNumber);
outList.Add(Char.ConvertFromUtf32(c));
}
}
else if (!String.IsNullOrEmpty(tchar))
{
if (curskip > 0)
{
curskip -= 1;
}
else if (!ignorable)
{
outList.Add(tchar);
}
}
}
}
else
{
// Didn't match the regex
returnString = inputRtf;
}
returnString = String.Join(String.Empty, outList.ToArray());
return returnString;
}
public class PickerItems
{
public string Name { get; set; }
}
}
}
修改
我想我不得不提到FromRTFConverter的类，但是我应该为该类提供什么接口？
还是有一种简单的方法可以在xamarin表单中创建富文本框？
我不知道如何解决此问题。有什么建议么？
答案 0 :(得分：0)
根据杰拉尔德（Gerald）的评论，假设您的转换器与demoapp位于同一名称空间（不是 demoapp.SubNamespace或其他任何名称），则以下各项应该可以正常工作：
<ContentPage
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:demoapp"
xmlns:converters="clr-namespace:demoapp"
x:Class="demoapp.MainPage">
...
<Editor
Text="{Binding CaretNote, Mode=OneWay, Converter={converters:FromRTFConverter}}"
...
/>
...
</ContentPage>