Question

我在我的monoandroid应用程序中使用 Cairo.Matrix dll 来加载一些System.Drawing.Drawing2D.Matix类方法它在构建时工作正常但在运行时从开罗的Matrix类.Matrix给出错误“System.NullReferenceException：对象引用未设置为对象的实例。” 当我初学Cairo.Matrix类错误“加载dicom filelibcairo-2.dll时出现异常。”

以下代码我正在尝试..........

using System; 

using System.Drawing; 

using Medsynaptic.Common;

using Medsynaptic.Imaging1.Mathematics; 

**using Matrix = Cairo.Matrix;**

public class SpatialTransform : ISpatialTransform 

    { 

private Cairo.Matrix _cumulativeTransform; 

        private Cairo.Matrix _transform; 

public PointF ConvertToDestination(PointF sourcePoint) 

        { 

            double x = 0.0, y = 0.0;         

            this.CumulativeTransform.TransformPoint(ref x, ref y);      

            PointF point = new PointF((float)x, (float)y); 

            return point; 
        }

这里显示Null Ref Exception：对象引用未设置为对象的实例

public Cairo.Matrix CumulativeTransform       
    {        

        get 

        {      

            Calculate(); 

            return _cumulativeTransform; 

        } 

    } 

 protected virtual void Calculate() 

    { 

        if (!this.RecalculationRequired) 

            return;

ERROR @ if condition： - 对象引用未设置为对象的实例

        if (_cumulativeTransform == null) 

            _cumulativeTransform = new Cairo.Matrix(); 


       // _cumulativeTransform.Reset(); 

        _cumulativeTransform.InitIdentity(); 
} 

}

这是android调试器显示输出错误错误加载 libcairo-2.dll

On Create Call

Picture box OnAttachedToWindow.

 display.Height 430

  firstRowHeight 43

  pictureBox.DisplayHeight 301

Displaying image /mnt/sdcard/Images/Series1/1.2.840.113619.2.22.287.1.20040913.195606.dcm

Request garbage collector to initiate.

Presentation Image created.

 Calling invalidate in Render Mode

Renderer will take care of it.

 Calling DrawSceneGraph

Error In loading

libcairo-2.DLL

 Picture box on draw called

 Displayed medsynaptic.medsynapse/desktopexecutable.Activity1: +1m10s925ms

Answer 1

不幸的是，包含Mono.Cairo.dll是一个错误;它无法工作，因为它取决于Android没有提供的原生libcairo.so。 Mono.Cairo.dll将在下一个版本中删除。

Cairo.Matrix dll提供的错误对象引用未设置为对象的实例

1 个答案: