班级成员的可见性/访问权限

Class Form1 { 公共标签label1 ... private void func1（） { iterateRows（）; } } Class1.cs ========= 使用NS; 公共类GetLabel { private void iterateRows（） { Form1 .label1.Text =" some value"; } } 方法iterateRows实际上是在执行循环操作我只想要 在每次迭代时在label1中显示值;简单吧？应该是 但是这里看不到label1 ......我在文档中找不到任何东西 这让我明白为什么Form1.label1.Text不可见。 ..这种类似的东西曾经是C中的一块蛋糕。 ..但是我已经远离编码 了一段时间... 我想我可以将对label1的引用传递给iterateRows（）和使这个 工作？但是我不愿意，我想知道为什么这不起作用 无论如何 感谢您的帮助/解释...... L 解决方案 Liz， 如果我不错过我的猜测，真正的问题是Form1，而不是label1。由于 已编码，因此您可以看到label1，因为您将其声明为public。但是在Form1中它是 。 Form1是一个类名。它不是一个实例变量。换句话说 它是事物的蓝图，而不是事物本身。 在运行时，代码中的某个地方，你是创建 表格的*实例*，类似于： 表格myForm = new Form1（）; myForm参考 - 或其副本 - 是你需要在你的GetLabel课程中引用 ： myForm.label1 .Text =some value; 问题是，myForm只是它所创建的代码的局部变量 并且在另一个班级中也看不到。这就是 封装的全部内容。 一些解决方案： 1）发送表格实例到GetLabel的构造函数： 表格myForm = new Form1（）; GetLabel labelGetter = new GetLabel（myForm）; 在GetLabel构造函数中，将该实例存储在 GetLabel的私有成员中，稍后您可以在GetLabel方法代码中引用它： this.theForm.label1.Text =" Whatever"; 2）GetLabel的公共财产接受表格： GetLabel labelGetter = new GetLabel（）; labelGetter.TheForm = new Form1（）; 3）另一种可能性是将表单实例存储在第三类， 表单管理器或全局对象缓存。这实际上是概念上与你可能想到的最接近的b $ b。例如： public class Globals { public static Form TheForm; 公共静态字符串ConnectionString; //其他所需的东西 } .... //无论你在哪里创建表格 Globals.TheForm = new Form1（）; .... //在你的GetLabel课程中 Globals.TheForm.label1.Text =不管; 请注意，由于我们正在处理静态成员，我们可以通过它们来解决这些问题 没有Globals实例的类名。 所有上述代码都是袖手旁观，未经测试，不保证 适合特定用途的适销性或适用性，yadda-yadda，但 这可以让你朝着正确的方向前进。 两个最终和无关的建议词： a）我不会将表单控件公开为公共字段。仅公开 必须可公开访问的内容，并使用描述性名称。对于 示例，编写一个名为，例如，RowLabelText的public * property *，并使其具有 getter和setter引用label1.Text。保持label1受到保护。 b）GetLabel描述的是一个动作，而不是一个东西，因此对于一个对象来说是一个糟糕的名字。 一个对象（这是一个东西）。 LabelGetter怎么样？ --BOB Liz写道：好的，这真的很简单，或者它应该......但是我被卡住了 在Windows窗体应用程序中，我有类似的东西： Form1.cs == ====== 命名空间NS Class Form1 {公共标签label1 ... private void func1（） { iterateRows（）; } Class1.cs ========= 使用NS; 公共类GetLabel { private void iterateRows（） { Form1.label1.Text =有些价值; } 方法iterateRows实际上是在执行循环操作而我只是希望在每次迭代时在label1中显示值;简单吧？应该是但是label1在这里是看不到的......我在文档中找不到任何内容哪个让我明白为什么Form1.label1.Text不可见......这种曾经是C中的一块蛋糕的东西。 ..但是我已经远离编码了一段时间...... 我想我可以将对label1的引用传递给iterateRows（）并使其工作吗？但我不愿意，我想知道为什么这不起作用 感谢您的帮助/解释...... Liz， 如果我不错过我的猜测，真正的问题是Form1，而不是label1。由于 已编码，因此您可以看到label1，因为您将其声明为public。但是在Form1中它是 。 Form1是一个类名。它不是一个实例变量。换句话说 它是事物的蓝图，而不是事物本身。 在运行时，代码中的某个地方，你是创建 表格的*实例*，类似于： 表格myForm = new Form1（）; myForm参考 - 或其副本 - 是你需要在你的GetLabel课程中引用 ： myForm.label1 .Text =some value; 问题是，myForm只是它所创建的代码的局部变量 并且在另一个班级中也看不到。这就是 封装的全部内容。 一些解决方案： 1）发送表格实例到GetLabel的构造函数： 表格myForm = new Form1（）; GetLabel labelGetter = new GetLabel（myForm）; 在GetLabel构造函数中，将该实例存储在 GetLabel的私有成员中，稍后您可以在GetLabel方法代码中引用它： this.theForm.label1.Text =" Whatever"; 2）GetLabel的公共财产接受表格： GetLabel labelGetter = new GetLabel（）; labelGetter.TheForm = new Form1（）; 3）另一种可能性是将表单实例存储在第三类， 表单管理器或全局对象缓存。这实际上是概念上与你可能想到的最接近的b $ b。例如： public class Globals { public static Form TheForm; 公共静态字符串ConnectionString; //其他所需的东西 } .... //无论你在哪里创建表格 Globals.TheForm = new Form1（）; .... //在你的GetLabel课程中 Globals.TheForm.label1.Text =不管; 请注意，由于我们正在处理静态成员，我们可以通过它们来解决这些问题 没有Globals实例的类名。 所有上述代码都是袖手旁观，未经测试，不保证 适合特定用途的适销性或适用性，yadda-yadda，但 这可以让你朝着正确的方向前进。 两个最终和无关的建议词： a）我不会将表单控件公开为公共字段。仅公开 必须可公开访问的内容，并使用描述性名称。对于 示例，编写一个名为，例如，RowLabelText的public * property *，并使其具有 getter和setter引用label1.Text。保持label1受到保护。 b）GetLabel描述的是一个动作，而不是一个东西，因此对于一个对象来说是一个糟糕的名字。 一个对象（这是一个东西）。 LabelGetter怎么样？ --BOB Liz写道：好的，这真的很简单，或者它应该......但是我被卡住了 在Windows窗体应用程序中，我有类似的东西： Form1.cs == ====== 命名空间NS Class Form1 {公共标签label1 ... private void func1（） { iterateRows（）; } Class1.cs ========= 使用NS; 公共类GetLabel { private void iterateRows（） { Form1.label1.Text =有些价值; } 方法iterateRows实际上是在执行循环操作而我只是希望在每次迭代时在label1中显示值;简单吧？应该是但是label1在这里是看不到的......我在文档中找不到任何内容哪个让我明白为什么Form1.label1.Text不可见......这种曾经是C中的一块蛋糕的东西。 ..但是我已经远离编码了一段时间...... 我想我可以将对label1的引用传递给iterateRows（）并使其工作吗？但我不愿意，我想知道为什么这不起作用 感谢您的帮助/解释...... " Bob Grommes" < bo*@bobgrommes.com>在消息中写道 新闻：#b ************** @ TK2MSFTNGP09.phx.gbl ... Liz， 如果我不错过我的猜测，真正的问题是Form1，而不是label1。由于已编码，因此您可以看到label1，因为您将其声明为public。但它在Form1中是 Form1是一个类名。它不是一个实例变量。换句话说，它是事物的蓝图，而不是事物本身。 我得到的很多......但即使我这样做： ============ ====================================== ========== 公共类Form1 { public Form myForm; //作为课堂声明 ..... } static void Main（）{ 表单myForm = new Form1（）; Application.Run（myForm） } === =============================================== === ======= 即使然后......在IDE中，如果我键入myForm。代码完成没有 显示我的公共var" label1" ......我不明白; IDE应该 理解 label1将是实例化的对象的成员var，不是吗？所以它应该让我为它做一个任务我会想的......但是它不会......（不，我不认为IDE坏了但我有 还没弄清楚我在这里做错了什么） 我只需将对label1的引用传递给即可完成这项工作在另一个.CS文件中的迭代方法..但是我不喜欢无法使用我的.CS中的参考label1做一个看似简单的事情。 $> 方法我打算用 其余的建议给我一些思考的东西......谢谢 输入请随意添加任何其他想法！ Liz 在运行时，代码中的某个地方，你是创建表单的*实例*，类似于： 表单myForm = new Form1（）; myForm参考 - 或副本它 - 你需要在你的GetLabel课程中引用： myForm.label1.Text =" some value" ;; 事实是，myForm只是它所创建的代码的局部变量，也不是在另一个班级中可见。这就是封装的全部内容。 一些解决方案： 1）将表单实例发送到GetLabel的构造函数： 表单myForm = new Form1（）; GetLabel labelGetter = new GetLabel（myForm）; 在GetLabel构造函数中，将该实例存储在GetLabel的私有成员中，然后你可以在以后的GetLabel方法代码中引用它： this.theForm.label1.Text =" Whatever" ;; 2）拥有GetLabel的公共财产接受表格： GetLabel labelGetter = new GetLabel（）; labelGetter.TheForm = new Form1（）; 3）另一种可能性是存储表单实例在第三类中，表单管理器或全局对象缓存。实际上，这与你可能想到的最接近概念。例如： public class Globals { public static Form TheForm; 公共静态字符串ConnectionString; //其他东西根据需要} // //无论你在哪里创建表格 Globals.TheForm = new Form1（）; ... //在你的GetLabel课程中 Globals.TheForm.label1.Text =" whatever" 请注意，既然我们正在处理静态成员，我们可以通过类名来解决它们必须有一个Globals的实例。 所有上述代码都是袖手旁观，未经测试，不保证适销性或特定用途的适用性，yadda-yadda，但是这应该会让你朝着正确的方向前进。 两个最终和无关的建议词： a）我不会将表单控件公开为公共字段。仅公开必须公开访问的内容，并使用描述性的名称。对于示例，将一个名为public * property *的代码命名为RowLabelText，并使其具有 getter和setter引用label1.Text。保持label1受到保护。 b）GetLabel描述了一个动作，而不是一个东西，因此对象（这是一个东西）是一个糟糕的名称。 LabelGetter怎么样？ - BOB Liz写道：好吧，这真的很简单，或者应该是...但是我被困了 在Windows窗体应用程序中，我有类似的东西： Form1.cs ======== Class Form1 {公共标签label1 ... 私有void func1（） { iterateRows（）; } Class1.cs ======== = 使用NS; 公共类GetLabel {void private iterateRows（） { Form1.label1。 Text =some value; } 方法iterateRows实际上是在执行循环操作而我只想想显示值在每次迭代的label1中;简单吧？应该是但是这里看不到label1 ...我在文档中找不到任何东西，这清楚地告诉我为什么Form1.label1.Text不可见...这个种类曾经是C中的一块蛋糕的东西。 ..但是我已经离开编码了一段时间... 我想我可以将对label1的引用传递给iterateRows（）并使这个工作？但是我不愿意，而且我想明白为什么在任何情况下这都不会是b $ b工作 感谢您的帮助/解释...... L ok, this is really simple stuff, or it should be ... but I''m stuckIn a Windows Forms app, I have something resembling this:Form1.cs========namespace NSClass Form1{public Label label1...private void func1(){iterateRows();}}Class1.cs=========using NS;public class GetLabel{private void iterateRows(){Form1.label1.Text = "some value";}}the method iterateRows is really performing a loop operation and I just wantto show values in label1 with each iteration; simple, right ? should bebut label1 is not visible from here ... I cannot find anything in the docswhich makes clear to me why Form1.label1.Text is not visible ... this kindof stuff used to be a piece of cake in "C" .. but I''ve been away from codingfor awhile ...I suppose I could pass a reference to label1 to iterateRows() and make thiswork ? but I''d rather not and I''d like to understand why this won''t workin any caseThanks for any help/explanations ...L 解决方案 Liz,If I don''t miss my guess, the real problem is Form1, not label1. Ascoded, label1 would be visible, since you declared it public. But it''swithin Form1.Form1 is a class name. It''s not an instance variable. In other wordsit''s the blueprint for the thing, not the thing itself.At runtime, somewhere in your code, you''re creating an *instance* of theform, along the lines of:Form myForm = new Form1();The myForm reference -- or a copy of it -- is what you need to referencein your GetLabel class:myForm.label1.Text = "some value";The thing is, myForm will just be a local variable to the code it''screated by, and also not visible in another class. That''s whatencapsulation is all about.Some solutions:1) Send the form instance to the constructor of GetLabel:Form myForm = new Form1();GetLabel labelGetter = new GetLabel(myForm);In the GetLabel constructor, store that instance in a private member ofGetLabel, then you can reference it later in GetLabel method code:this.theForm.label1.Text = "Whatever";2) Have a public property of GetLabel accept a Form:GetLabel labelGetter = new GetLabel();labelGetter.TheForm = new Form1();3) Another possibility is to store the form instance in a third class,either a form manager or a global objects cache. This is actuallyclosest conceptually to what you''re probably thinking of. For example:public class Globals {public static Form TheForm;public static string ConnectionString;// other stuff as needed}....// wherever you create the formGlobals.TheForm = new Form1();....// within your GetLabel classGlobals.TheForm.label1.Text = "whatever";Notice that since we''re dealing with static members, we can address themthrough the class name without having to have an instance of Globals.All of the above code is off-the-cuff and untested, no warranty as tomerchantability or fitness for a particular purpose, yadda-yadda, butthis should get you heading in the right direction.Two final and unrelated words of advice:a) I would not expose form controls as public fields. Expose only whatmust be publicly accessible, and use a name that is descriptive. Forexample, code a public *property* named, say, RowLabelText, and have itsgetter and setter reference label1.Text. Keep label1 protected.b) GetLabel describes an action, not a thing, and so is a lousy name foran object (which is a thing). How about LabelGetter?--BobLiz wrote: ok, this is really simple stuff, or it should be ... but I''m stuck In a Windows Forms app, I have something resembling this: Form1.cs ======== namespace NS Class Form1 { public Label label1 ... private void func1() { iterateRows(); } } Class1.cs ========= using NS; public class GetLabel { private void iterateRows() { Form1.label1.Text = "some value"; } } the method iterateRows is really performing a loop operation and I just want to show values in label1 with each iteration; simple, right ? should be but label1 is not visible from here ... I cannot find anything in the docs which makes clear to me why Form1.label1.Text is not visible ... this kind of stuff used to be a piece of cake in "C" .. but I''ve been away from coding for awhile ... I suppose I could pass a reference to label1 to iterateRows() and make this work ? but I''d rather not and I''d like to understand why this won''t work in any case Thanks for any help/explanations ... L Liz,If I don''t miss my guess, the real problem is Form1, not label1. Ascoded, label1 would be visible, since you declared it public. But it''swithin Form1.Form1 is a class name. It''s not an instance variable. In other wordsit''s the blueprint for the thing, not the thing itself.At runtime, somewhere in your code, you''re creating an *instance* of theform, along the lines of:Form myForm = new Form1();The myForm reference -- or a copy of it -- is what you need to referencein your GetLabel class:myForm.label1.Text = "some value";The thing is, myForm will just be a local variable to the code it''screated by, and also not visible in another class. That''s whatencapsulation is all about.Some solutions:1) Send the form instance to the constructor of GetLabel:Form myForm = new Form1();GetLabel labelGetter = new GetLabel(myForm);In the GetLabel constructor, store that instance in a private member ofGetLabel, then you can reference it later in GetLabel method code:this.theForm.label1.Text = "Whatever";2) Have a public property of GetLabel accept a Form:GetLabel labelGetter = new GetLabel();labelGetter.TheForm = new Form1();3) Another possibility is to store the form instance in a third class,either a form manager or a global objects cache. This is actuallyclosest conceptually to what you''re probably thinking of. For example:public class Globals {public static Form TheForm;public static string ConnectionString;// other stuff as needed}....// wherever you create the formGlobals.TheForm = new Form1();....// within your GetLabel classGlobals.TheForm.label1.Text = "whatever";Notice that since we''re dealing with static members, we can address themthrough the class name without having to have an instance of Globals.All of the above code is off-the-cuff and untested, no warranty as tomerchantability or fitness for a particular purpose, yadda-yadda, butthis should get you heading in the right direction.Two final and unrelated words of advice:a) I would not expose form controls as public fields. Expose only whatmust be publicly accessible, and use a name that is descriptive. Forexample, code a public *property* named, say, RowLabelText, and have itsgetter and setter reference label1.Text. Keep label1 protected.b) GetLabel describes an action, not a thing, and so is a lousy name foran object (which is a thing). How about LabelGetter?--BobLiz wrote: ok, this is really simple stuff, or it should be ... but I''m stuck In a Windows Forms app, I have something resembling this: Form1.cs ======== namespace NS Class Form1 { public Label label1 ... private void func1() { iterateRows(); } } Class1.cs ========= using NS; public class GetLabel { private void iterateRows() { Form1.label1.Text = "some value"; } } the method iterateRows is really performing a loop operation and I just want to show values in label1 with each iteration; simple, right ? should be but label1 is not visible from here ... I cannot find anything in the docs which makes clear to me why Form1.label1.Text is not visible ... this kind of stuff used to be a piece of cake in "C" .. but I''ve been away from coding for awhile ... I suppose I could pass a reference to label1 to iterateRows() and make this work ? but I''d rather not and I''d like to understand why this won''t work in any case Thanks for any help/explanations ... L"Bob Grommes" <bo*@bobgrommes.com> wrote in messagenews:#b**************@TK2MSFTNGP09.phx.gbl... Liz, If I don''t miss my guess, the real problem is Form1, not label1. As coded, label1 would be visible, since you declared it public. But it''s within Form1. Form1 is a class name. It''s not an instance variable. In other words it''s the blueprint for the thing, not the thing itself.that much I get ... but even if I do this:================================================== ==========public class Form1{public Form myForm; // as a class declaration.....}static void Main(){Form myForm = new Form1();Application.Run(myForm)}================================================== ==========even then ... in the IDE, if I type "myForm." the code completion does notshow my public var "label1" ... this I don''t understand; the IDE should"understand" that label1 WILL be a member var of the object when it''sinstantiated, no ? so it should let me make an assignment to it I wouldthink ... but it won''t ... (no, I don''t think the IDE is broken but I havenot yet figured out what I''m doing wrong here)I CAN make this work simply by passing a reference to label1 to theiteration method in the other .CS file .. but I don''t like not being able todo a seemingly simple thing like reference label1 from my .CS with all themethods I''m going to useThe rest of your suggestions give me some things to think about ... thanksfor the input and please feel free to add any other thoughts !Liz At runtime, somewhere in your code, you''re creating an *instance* of the form, along the lines of: Form myForm = new Form1(); The myForm reference -- or a copy of it -- is what you need to reference in your GetLabel class: myForm.label1.Text = "some value"; The thing is, myForm will just be a local variable to the code it''s created by, and also not visible in another class. That''s what encapsulation is all about. Some solutions: 1) Send the form instance to the constructor of GetLabel: Form myForm = new Form1(); GetLabel labelGetter = new GetLabel(myForm); In the GetLabel constructor, store that instance in a private member of GetLabel, then you can reference it later in GetLabel method code: this.theForm.label1.Text = "Whatever"; 2) Have a public property of GetLabel accept a Form: GetLabel labelGetter = new GetLabel(); labelGetter.TheForm = new Form1(); 3) Another possibility is to store the form instance in a third class, either a form manager or a global objects cache. This is actually closest conceptually to what you''re probably thinking of. For example: public class Globals { public static Form TheForm; public static string ConnectionString; // other stuff as needed } ... // wherever you create the form Globals.TheForm = new Form1(); ... // within your GetLabel class Globals.TheForm.label1.Text = "whatever"; Notice that since we''re dealing with static members, we can address them through the class name without having to have an instance of Globals. All of the above code is off-the-cuff and untested, no warranty as to merchantability or fitness for a particular purpose, yadda-yadda, but this should get you heading in the right direction. Two final and unrelated words of advice: a) I would not expose form controls as public fields. Expose only what must be publicly accessible, and use a name that is descriptive. For example, code a public *property* named, say, RowLabelText, and have its getter and setter reference label1.Text. Keep label1 protected. b) GetLabel describes an action, not a thing, and so is a lousy name for an object (which is a thing). How about LabelGetter? --Bob Liz wrote: ok, this is really simple stuff, or it should be ... but I''m stuck In a Windows Forms app, I have something resembling this: Form1.cs ======== namespace NS Class Form1 { public Label label1 ... private void func1() { iterateRows(); } } Class1.cs ========= using NS; public class GetLabel { private void iterateRows() { Form1.label1.Text = "some value"; } } the method iterateRows is really performing a loop operation and I justwant to show values in label1 with each iteration; simple, right ? shouldbe but label1 is not visible from here ... I cannot find anything in thedocs which makes clear to me why Form1.label1.Text is not visible ... thiskind of stuff used to be a piece of cake in "C" .. but I''ve been away fromcoding for awhile ... I suppose I could pass a reference to label1 to iterateRows() and makethis work ? but I''d rather not and I''d like to understand why this won''twork in any case Thanks for any help/explanations ... L 这篇关于班级成员的可见性/访问权限的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！