Android 如何以编程方式触发 Onclick 事件？
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How can I fire Onclick event programmatically?
提问by Zakaria
I have a custom view with 2 linear layouts: the first is the view's header and the second is the the details view.
我有一个带有 2 个线性布局的自定义视图：第一个是视图的标题，第二个是详细信息视图。
In the custom view, the OnClickListener of the header Linearlayout is already defined: when it fires, it collapses/expandes the second linearlayout.
在自定义视图中，标题 Linearlayout 的 OnClickListener 已经定义：当它触发时，它会折叠/展开第二个线性布局。
What I want to do is to add more functionalities to my header's OnClickListener event (i.e.: collapse/expand the second layout and show a Toast).
我想要做的是向我的标题的 OnClickListener 事件添加更多功能（即：折叠/展开第二个布局并显示 Toast）。
I can't modify the source code of the custom view. I tried to set a new OnClickListener but it hides the initial event (collapse/expand).
我无法修改自定义视图的源代码。我试图设置一个新的 OnClickListener 但它隐藏了初始事件（折叠/展开）。
How should I implement this?
我应该如何实施？
The source code of My Custom View:
我的自定义视图的源代码：
public class ExpandoLayout extends ViewGroup
{
/* some declarations */
private Linearlayout header;
private linearlayout footer;
/* some code */
@override
protected void onFinishInflate() {
header= new LinearLayout(context);
header.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
toggleExpand();
}
});
}
}
What I want to do is to add some code to the already defined OnClickListener event in my activity. Something like that:
我想要做的是向我的活动中已经定义的 OnClickListener 事件添加一些代码。类似的东西：
public class myActivity extends Activity {
private Linearlayout myCustomView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.rsdetail);
myCustomView= (MyCustomView) findViewById(R.id.expanded);
myCustomView.getChildAt(0).setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if(v instanceof LinearLayout)
{
v.performClick();
Toast.makeText(getActivity(), "ExpandoOnClickListener", 2000).show();
}
}
});
}
采纳答案by Vladimir
Simple solution would be to get original OnClickListener and then fire it in new one:
简单的解决方案是获取原始 OnClickListener 然后在新的中触发它：
final OnClickListener preDefinedListener = myCustomView.getChildAt(0).getOnClickListner();
myCustomView.getChildAt(0).setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if(v instanceof LinearLayout)
{
preDefinedListener.onClick(v); // calls default (defined by MyCustomView)
Toast.makeText(getActivity(), "ExpandoOnClickListener", 2000).show();
}
}
});
Sadly, Viewdoes not have getOnClickListner(), but I guess you can use reflectionto get it. It is stored in the fieldmOnClickListener(source).
可悲的是，View没有getOnClickListner()，但我想您可以使用反射来获取它。它存储在字段mOnClickListener( source) 中。
This is how you can get OnClickListenerdefined for your layout:
这是您可以OnClickListener为您的布局定义的方式：
OnClickListener tmpOnClickListener = null;
try {
Class<View> cls = (Class<View>) Class.forName("android.view.View");
Field fld = cls.getDeclaredField("mOnClickListener");
fld.setAccessible(true); // because it is protected
tmpOnClickListener = (OnClickListener) fld.get(myCustomView.getChildAt(0));
fld.setAccessible(false); // restore it's original property
} catch (SecurityException e) {
e.printStackTrace();
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
final OnClickListener preDefinedListener = tmpOnClickListener;
if (preDefinedListener != null) {
myCustomView.getChildAt(0).setOnClickListener(new OnClickListener() {
@Override
public void onClick(View paramView) {
preDefinedListener.onClick(paramView);
Toast.makeText(getActivity(), "ExpandoOnClickListener", Toast.LENGTH_LONG).show();
}
});
I didn't really bother to handle all exception correctly, but it's enough to get the idea. It might look messy, but it's actually just 5 lines of new code to solve your problem.
我并没有真正费心去正确处理所有异常，但这足以理解这个想法。它可能看起来很乱，但实际上只需 5 行新代码即可解决您的问题。
回答by waqaslam
You can programmatically raise click event on a View to call it's OnClickListeneras below:
您可以以编程方式在视图上引发单击事件以调用它OnClickListener，如下所示：
view.performClick();
Now if you call this on your second layout under first layout's OnClickListenerthen i hope it should do the magic
现在，如果您在第一个布局的OnClickListener下在您的第二个布局上调用它，那么我希望它应该能发挥作用
回答by Vadim
Since SDK 15 you can just call method:
从 SDK 15 开始，您只需调用方法：
view.callOnClick()
回答by Sudhaker
If you cannot modify the code of CustomView then you have the below option.
如果您无法修改 CustomView 的代码，那么您可以选择以下选项。
- Extend the CustomView.
- Override the onClick() method and bind this as a Listener to the first layout.
- Inside onClick() first call super.onClick() then add your additional functionality below.
- 扩展自定义视图。
- 覆盖 onClick() 方法并将其作为侦听器绑定到第一个布局。
- 在 onClick() 内部首先调用 super.onClick() 然后在下面添加您的附加功能。
This way you are keeping the existing code and adding additional functionality as well.
通过这种方式，您可以保留现有代码并添加其他功能。
