C#隐式转换显式求教

Question

1
2小白求教大神该如何去解决这个问题

Answer 1

贴完整代码。你的程序中有2个SelectedShape的定义。

Answer 2

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
// For the binary formatter.
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
namespace shiyan04
{
    public partial class MyPaintProgram : Form
    {
        public MyPaintProgram()
        {
            InitializeComponent();
        }        private void exitToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }        // 需要呈现的当前形状/颜色。
        private SelectedShape currentShape;
        private Color currentColor = Color.DarkBlue;        // 维护每个ShapeData
        private List<ShapeData> shapes = new List<ShapeData>();        private void MainWindow_Paint(object sender, PaintEventArgs e)
        {
            // Get the Graphics type for this window.
            Graphics g = e.Graphics;            // Render each shape in the selected color. 
            foreach (ShapeData s in shapes)
            {
                // Render a rectangle or circle 20 x 20 pixels in size
                // using the correct color. 
                if (s.ShapeType == SelectedShape.Rectangle)
                    g.FillRectangle(new SolidBrush(s.Color), s.UpperLeftPoint.X, s.UpperLeftPoint.Y, 20, 20);
                else
                    g.FillEllipse(new SolidBrush(s.Color), s.UpperLeftPoint.X, s.UpperLeftPoint.Y, 20, 20);
            }        }        private void MainWindow_MouseClick(object sender, MouseEventArgs e)
        {
            // Make a ShapeData type based on current user
            // selections.
            ShapeData sd = new ShapeData();
            sd.ShapeType = currentShape;
            sd.Color = currentColor;
            sd.UpperLeftPoint = new Point(e.X, e.Y);            // Add to the List<T> and forse the form to repaint itself. 
            shapes.Add(sd);
            Invalidate();        }        private void pickShapeToolStripMenuItem_Click(object sender, EventArgs e)
        {
            ShapePickerDialog dlg = new ShapePickerDialog();
            if (DialogResult.OK == dlg.ShowDialog())
            {
                currentShape = dlg.SelectedShape;
            }        }        private void pickColorToolStripMenuItem_Click(object sender, EventArgs e)
        {
            ColorDialog dlg = new ColorDialog();            if (dlg.ShowDialog() == DialogResult.OK)
            {
                currentColor = dlg.Color;
            }        }        private void clearSurfaceToolStripMenuItem_Click(object sender, EventArgs e)
        {
            shapes.Clear();            // This will fire the paint event.
            Invalidate();        }        private void saveToolStripMenuItem_Click(object sender, EventArgs e)
        {
            using (SaveFileDialog saveDlg = new SaveFileDialog())
            {
                // 配置Save对话框的外观
                saveDlg.InitialDirectory = ".";
                saveDlg.Filter = "Shape files (*.shapes)|*.shapes";
                saveDlg.RestoreDirectory = true;
                saveDlg.FileName = "MyShapes";                // 如果点击了OK按钮，就会打开新的文件并且序列化List<T>        
                if (saveDlg.ShowDialog() == DialogResult.OK)
                {
                    Stream myStream = saveDlg.OpenFile();
                    if ((myStream != null))
                    {
                        // 保存所有的形状!
                        BinaryFormatter myBinaryFormat = new BinaryFormatter();
                        myBinaryFormat.Serialize(myStream, shapes);
                        myStream.Close();
                    }
                }
            }        }        private void loadToolStripMenuItem_Click(object sender, EventArgs e)
        {
            using (OpenFileDialog openDlg = new OpenFileDialog())
            {
                openDlg.InitialDirectory = ".";
                openDlg.Filter = "Shape files (*.shapes)|*.shapes";
                openDlg.RestoreDirectory = true;
                openDlg.FileName = "MyShapes";                if (openDlg.ShowDialog() == DialogResult.OK)
                {
                    Stream myStream = openDlg.OpenFile();
                    if ((myStream != null))
                    {
                        // 获取所有形状!
                        BinaryFormatter myBinaryFormat = new BinaryFormatter();
                        shapes = (List<ShapeData>)myBinaryFormat.Deserialize(myStream);
                        myStream.Close();
                        Invalidate();
                    }
                }
            }        }        
    }
}

Answer 3

请将各类之间的关系贴出来，否则，无法判断是否能转换。
如currentshape 
s.shapetype

Answer 4

ShapeData类的定义
SelectShape类的定义

Answer 5

private SelectedShape currentShape;=>private shiyan04.SelectedShape currentShape;