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如何检查对象的类型[iOS/Android/Windows Phone]

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iOS

使用 NSObject 基類的 isKindOfClass: 方法。

聲明:

- (BOOL)isKindOfClass:(Class)aClass
描述:
Returns a Boolean value that indicates whether the receiver is an instance of given class or an instance of any class that inherits from that class. (required)

參數(shù):

aClass: A class object representing the Objective-C class to be tested.

返回值:

YES if the receiver is an instance of aClass or an instance of any class that inherits from aClass, otherwise NO.

示例代碼:

for?(UIView?*ctrl?in?[self?childViewControllers])?{
????if?([ctrl?isKindOfClass:[UITextField?class]])?{
????????[(UITextField*)ctrl?setText:@""];
????}
????else?if?([ctrl?isKindOfClass:[UISwitch?class]])?{
????????[(UISwitch*)ctrl?setOn:NO];
????}
}

?

Android

The instanceof operator compares an object to a specified type. You can use it to test if an object is an instance of a class, an instance of a subclass, or an instance of a class that implements a particular interface.

示例代碼:

void?checkforTextView(View?v)
{
??? if(v?instanceof?TextView)
????{
????????//?This?is?a?TextView?control
????}?else?{
????????//?This?is?not?a?TextView?control
????}
}


Windows Phone

C# 的 is 操作符關(guān)鍵字。Checks if an object is compatible with a given type. An is expression evaluates to true if the provided expression is non-null, and the provided object can be cast to the provided type without causing an exception to be thrown.

示例代碼:

foreach?(UIElement?ctrl?in?this.ContentPanel.Children)?{
????if?(ctrl?is?TextBlock)?{
????????//TextBlock
????}
????else?if?(ctrl?is?TextBox)?{
????????//TextBox
????}
}

?

作者:黎波
博客:http://bobli.cnblogs.com/
日期:2012年3月14日

轉(zhuǎn)載于:https://www.cnblogs.com/bobli/archive/2012/03/14/2395565.html

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