麻烦各位大神指点一下怎样用flutter写出一个首页？
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麻烦用fluter按照我这个图做这样的一个页面，中间的图片按钮我不会做了
针对中间的图片按钮，可以使用Wrap，或者两个Row。想要让图片有点击响应，需要在外层套一个InkWell。
参考样式：
参考代码：
Wrap(
alignment: WrapAlignment.center,
children: [
_imageButton(),
_imageButton(),
_imageButton(),
_imageButton(),
],
)
/// _imageButton
_imageButton()
return Container(
margin: EdgeInsets.all(10),
decoration: BoxDecoration(
border: Border.all(
color: Colors.black,
width: 1,
),
),
width: 180,
height: 180,
child: InkWell(
onTap: ()
debugPrint('点到了');
,
child: Image.network('https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1603704279075&di=4c112c130b61ed6aeab7a42f19439580&imgtype=0&src=http%3A%2F%2F5b0988e595225.cdn.sohucs.com%2Fimages%2F20180426%2F9427933c10a6402eb77a7480d709a20a.jpeg'),
),
);
自己封装了一个EF的上下文类.,分享一下,顺便求大神指点
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.Entity;
using System.Data.Entity.Core.Objects;
using System.Data.Entity.Infrastructure;
using System.Data.Entity.Migrations;
using System.Data.Entity.Validation;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;
using EntityFramework.Extensions;
using System.Threading.Tasks;
//using log4net;
//using log4net.Core;
namespace _6._0Test
{
/// <summary>
/// 上下文静态实体类
/// </summary>
public static class DbContentEntity
{
/// <summary>
/// 静态初始化
/// </summary>
static DbContentEntity()
{
if (string.IsNullOrEmpty(ConnectionString))
return;
if (_entities == null)
{
_entities = new TestEntities(ConnectionString);
_entities.Configuration.ValidateOnSaveEnabled = false;
}
if (_entities.Database.Connection.State == ConnectionState.Closed && _entities.Database.Connection.State != ConnectionState.Connecting)
{
_entities.Database.Connection.Open();
}
}
/// <summary>
/// 静态连接字符串
/// </summary>
public static string ConnectionString
{
get { return ConfigurationManager.ConnectionStrings["TestEntities"].ConnectionString; }
}
/// <summary>
/// 静态实体
/// </summary>
private static TestEntities _entities;
/// <summary>
/// 对外实体
/// </summary>
public static TestEntities Entities
{
get
{
if (string.IsNullOrEmpty(ConnectionString))
return null;
return _entities ?? (_entities = new TestEntities(ConnectionString));
}
}
}
/// <summary>
/// 上下文类
/// </summary>
/// <typeparam name="T"></typeparam>
public abstract class ModelContext<T> where T : class
{
//日志,可自行拓展
//public static ILog Log = LogManager.GetLogger(typeof(T).Name);
/// <summary>
/// 返回上下文实体
/// </summary>
protected TestEntities Entities
{
get { return DbContentEntity.Entities; }
}
private DbSet<T> _model;
protected DbSet<T> Model
{
get { return _model ?? (_model = Entities.Set<T>()); }
}
#region =====查询用方法=====
/// <summary>
/// 根据条件查询实体
/// </summary>
/// <param name="where">条件</param>
/// <returns>实体</returns>
public virtual T Get(Expression<Func<T, bool>> @where)
{
return Model.FirstOrDefault(where);
}
/// <summary>
/// 根据条件查询实体(异步)
/// </summary>
/// <param name="where">条件</param>
/// <returns>实体</returns>
public async virtual Task<T> GetAsync(Expression<Func<T, bool>> @where)
{
return await Model.FirstOrDefaultAsync(where);
}
/// <summary>
/// 根据条件查询实体集合(需自行tolist,自行异步)
/// </summary>
/// <param name="where">查询条件</param>
/// <returns></returns>
public virtual IQueryable<T> GetList(Expression<Func<T, bool>> @where)
{
return Model.AsNoTracking().Where(where);
}
/// <summary>
/// 根据条件查询实体集合(需自行tolist,自行异步)
/// </summary>
/// <param name="where">查询条件</param>
/// <returns></returns>
public async virtual Task<IQueryable<T>> GetListAsync(Expression<Func<T, bool>> @where)
{
return await Task.Run(()=>Model.AsNoTracking().Where(where));
}
/// <summary>
/// 根据传进来的实体类型查询该实体的集合
/// </summary>
/// <typeparam name="TM">实体类型</typeparam>
/// <param name="where">查询条件</param>
/// <returns></returns>
public virtual IQueryable<TM> GetList<TM>(Expression<Func<TM, bool>> @where) where TM : class
{
var model = Entities.Set<TM>();
return model.AsNoTracking().Where(where);
}
/// <summary>
/// 根据传进来的实体类型查询该实体(异步)
/// </summary>
/// <typeparam name="TM">实体类型</typeparam>
/// <param name="where">查询条件</param>
/// <returns></returns>
public async virtual Task<TM> GetAsync<TM>(Expression<Func<TM, bool>> @where) where TM : class
{
var model = Entities.Set<TM>();
return await model.FirstOrDefaultAsync(where);
}
/// <summary>
/// 根据条件查询实体数量
/// </summary>
/// <typeparam name="TM">实体类型</typeparam>
/// <param name="where">查询条件</param>
/// <returns></returns>
public virtual int Cout<TM>(Expression<Func<TM, bool>> @where) where TM : class
{
try
{
var model = Entities.Set<TM>();
return model.AsNoTracking().Count(where);
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return -1;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return -1;
}
}
/// <summary>
/// 根据条件查询实体数量(异步)
/// </summary>
/// <typeparam name="TM">实体类型</typeparam>
/// <param name="where">查询条件</param>
/// <returns></returns>
public async virtual Task<int> CoutAsync<TM>(Expression<Func<TM, bool>> @where) where TM : class
{
try
{
var model = Entities.Set<TM>();
return await model.AsNoTracking().CountAsync(where);
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return -1;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return -1;
}
}
/// <summary>
/// 根据条件查询实体数量
/// </summary>
/// <param name="where"></param>
/// <returns></returns>
public async virtual Task<int> Count(Expression<Func<T, bool>> @where)
{
try
{
var model = Entities.Set<T>();
return await model.AsNoTracking().CountAsync(where);
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return -1;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return -1;
}
}
#endregion
#region ====添加用方法====
/// <summary>
/// 添加实体
/// </summary>
/// <param name="m"></param>
/// <returns></returns>
public virtual bool Add(T m)
{
try
{
Model.Add(m);
Entities.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
/// 添加实体(异步)
/// </summary>
/// <param name="m"></param>
/// <returns></returns>
public async virtual Task<bool> AddAsync(T m)
{
try
{
Model.Add(m);
await Entities.SaveChangesAsync();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
/// 根据类型添加实体
/// </summary>
/// <typeparam name="TM"></typeparam>
/// <param name="tm"></param>
/// <returns></returns>
public virtual bool Add<TM>(TM tm) where TM : class
{
try
{
var model = Entities.Set<TM>();
model.Add(tm);
Entities.SaveChanges();
}
catch (DbEntityValidationException dbex)
{
//Log.Error(dbex + dbex.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
/// 批量添加实体
/// </summary>
/// <param name="m"></param>
/// <returns></returns>
public virtual bool AddRange(IEnumerable<T> m)
{
try
{
Model.AddRange(m);
Entities.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
/// 批量添加实体(异步)
/// </summary>
/// <param name="m"></param>
/// <returns></returns>
public async virtual Task<bool> AddRangeAsync(IEnumerable<T> m)
{
try
{
Model.AddRange(m);
await Entities.SaveChangesAsync();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
#endregion
#region ====修改用方法====
/// <summary>
/// 修改实体
/// </summary>
/// <param name="t"></param>
/// <returns></returns>
public virtual bool Update(T t)
{
try
{
Model.Attach(t);
Entities.Entry(t).State = EntityState.Modified;
Entities.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
/// 修改实体(异步)
/// </summary>
/// <param name="t"></param>
/// <returns></returns>
public async virtual Task<bool> UpdateAsync(T t)
{
try
{
Model.Attach(t);
Entities.Entry(t).State = EntityState.Modified;
await Entities.SaveChangesAsync();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
/// 根据类型修改实体
/// </summary>
/// <typeparam name="TM"></typeparam>
/// <param name="tm"></param>
/// <returns></returns>
public virtual bool Update<TM>(TM tm) where TM : class
{
try
{
var model = Entities.Set<TM>();
model.Attach(tm);
Entities.Entry(tm).State = EntityState.Modified;
Entities.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
/// 批量更新数据
/// </summary>
/// <param name="where">更新数据的条件 如:u => u.FirstName == "firstname"</param>
/// <param name="ex">更新的值 如:u=>new User{FirstName = "newfirstname"}</param>
/// <returns>返回影响的条数</returns>
public virtual int Update(Expression<Func<T, bool>> @where, Expression<Func<T, T>> ex)
{
try
{
return Model.Where(where).Update(ex);
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return -1;
}
catch (Exception e)
{
// Log.Error(e + e.Message);
return -1;
}
}
/// <summary>
/// 批量更新数据(异步)
/// </summary>
/// <param name="where">更新数据的条件 如:u => u.FirstName == "firstname"</param>
/// <param name="ex">更新的值 如:u=>new User{FirstName = "newfirstname"}</param>
/// <returns>返回影响的条数</returns>
public async virtual Task<int> UpdateAsync(Expression<Func<T, bool>> @where, Expression<Func<T, T>> ex)
{
try
{
return await Model.Where(where).UpdateAsync(ex);
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return -1;
}
catch (Exception e)
{
// Log.Error(e + e.Message);
return -1;
}
}
/// <summary>
/// 添加或者修改实体(无则添加,有则修改)
/// </summary>
/// <param name="m"></param>
/// <returns></returns>
public virtual bool AddOrUpdate(T[] m)
{
try
{
Model.AddOrUpdate(m);
Entities.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
// Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
/// 添加或者修改实体(无则添加,有则修改,异步)
/// </summary>
/// <param name="m"></param>
/// <returns></returns>
public async virtual Task<bool> AddOrUpdateAsync(T[] m)
{
try
{
Model.AddOrUpdate(m);
await Entities.SaveChangesAsync();
}
catch (DbEntityValidationException dbEx)
{
// Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
#endregion
#region ===事务====
/// <summary>
/// 运行基本事务,返回bool值
/// </summary>
/// <param name="model"></param>
/// <returns></returns>
protected bool RunTransaction(Action<DbSet<T>> model)
{
using (var transaction = Entities.Database.BeginTransaction())
{
try
{
model.Invoke(Model);
Entities.SaveChanges();
transaction.Commit();
return true;
}
catch (DbEntityValidationException dbEx)
{
//Log.Error("EXEC RunTransaction Error:" + dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error("EXEC RunTransaction Error:" + ex + ex.Message);
transaction.Rollback();
return false;
}
}
}
/// <summary>
/// 运行基本事务,返回bool值(异步)
/// </summary>
/// <param name="model"></param>
/// <returns></returns>
protected async Task<bool> RunTransactionAsync(Action<DbSet<T>> model)
{
using (var transaction = Entities.Database.BeginTransaction())
{
try
{
model.Invoke(Model);
await Entities.SaveChangesAsync();
transaction.Commit();
return true;
}
catch (DbEntityValidationException dbEx)
{
//Log.Error("EXEC RunTransaction Error:" + dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error("EXEC RunTransaction Error:" + ex + ex.Message);
transaction.Rollback();
return false;
}
}
}
#endregion
#region======删除用方法====
/// <summary>
/// 删除实体
/// </summary>
/// <param name="t"></param>
/// <returns></returns>
public virtual bool Remove(T t)
{
try
{
Model.Remove(t);
Entities.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
/// 删除实体(异步)
/// </summary>
/// <param name="t"></param>
/// <returns></returns>
public async virtual Task<bool> RemoveAsync(T t)
{
try
{
Model.Remove(t);
await Entities.SaveChangesAsync();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
/// 根据类型删除实体
/// </summary>
/// <typeparam name="TM"></typeparam>
/// <param name="m"></param>
/// <returns></returns>
public virtual bool Remove<TM>(TM m) where TM : class
{
try
{
var model = Entities.Set<TM>();
model.Remove(m);
Entities.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return false;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return false;
}
return true;
}
/// <summary>
///批量删除实体
/// </summary>
/// <param name="m"></param>
/// <returns></returns>
public virtual int RemoveRange(IEnumerable<T> m)
{
try
{
Model.RemoveRange(m);
return Entities.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return -1;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return -1;
}
}
/// <summary>
///批量删除实体(异步)
/// </summary>
/// <param name="m"></param>
/// <returns></returns>
public async virtual Task<int> RemoveRangeAsync(IEnumerable<T> m)
{
try
{
Model.RemoveRange(m);
return await Entities.SaveChangesAsync();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return -1;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return -1;
}
}
/// <summary>
/// 根据类型批量删除实体
/// </summary>
/// <typeparam name="TM"></typeparam>
/// <param name="tmMs"></param>
/// <returns></returns>
public virtual int RemoveRange<TM>(IEnumerable<TM> tmMs) where TM : class
{
try
{
var model = Entities.Set<TM>();
model.RemoveRange(tmMs);
return Entities.SaveChanges();
}
catch (DbEntityValidationException dbEx)
{
//Log.Error(dbEx + dbEx.Message);
return -1;
}
catch (Exception ex)
{
//Log.Error(ex + ex.Message);
return -1;
}
}
#endregion
}
}
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