我有一个包含的形式[安,约翰]值的ArrayList。我想此ArrayList转换为字符串数组的形式{安,约翰}。
我应该怎么做呢?
我的Android code:
最后按钮markabsent =(按钮)findViewById(R.id.Button02);
markabsent.setOnClickListener(新View.OnClickListener(){
公共无效的onClick(视图v){
//执行上的点击动作
Toast.makeText(display.this,你已经打上了学生缺席,Toast.LENGTH_SHORT).show();
SparseBooleanArray checkedabsent = lView.getCheckedItemPositions();
的for(int i = 0; I< arr2.length;我++)
{
如果(checkedabsent.get(i))的
{
items2.add(ARR2 [I]);
的System.out.println(items2);
}
}
Log.d(,项目);
对于(字符串字符串:items2)
{
Log.d(字符串,字符串);
}
}
});
我的logcat的:
11-10 21:44:00.414:信息/的System.out(2316):[安,约翰,安]
11-10 21:44:00.414:DEBUG /(2316):项目:
11-10 21:44:00.414:DEBUG /串(2316):安
11-10 21:44:00.414:DEBUG /串(2316):约翰
我试图做的答案提到的一切,但我的logcat只是似乎没有imrove
下面是一个给予例外:
11-10 22:14:20.855:信息/的System.out(3322):Ljava.lang.String; @ 44eb6ff0
11-10 22:16:38.186:ERROR / AndroidRuntime(3411):致命异常:主要
11-10 22:16:38.186:ERROR / AndroidRuntime(3411):java.lang.ClassCastException:[Ljava.lang.Object;
11-10 22:16:38.186:ERROR / AndroidRuntime(3411):在com.example.display $ 2.onClick(display.java:124)
11-10 22:16:38.186:ERROR / AndroidRuntime(3411):在android.view.View.performClick(View.java:2408)
11-10 22:16:38.186:ERROR / AndroidRuntime(3411):在android.view.View $ PerformClick.run(View.java:8816)
11-10 22:16:38.186:ERROR / AndroidRuntime(3411):在android.os.Handler.handleCallback(Handler.java:587)
下面是多了一个:
11-10 22:14:20.875:DEBUG /串(3322):安
11-10 22:14:20.875:信息/的System.out(3322):Ljava.lang.String; @ 44eb7720
11-10 22:14:20.875:信息/的System.out(3322):Ljava.lang.String; @ 44eb7720
11-10 22:14:20.885:信息/的System.out(3322):Ljava.lang.String; @ 44eb7720
11-10 22:14:20.895:DEBUG /串(3322):约翰
11-10 22:14:20.895:信息/的System.out(3322):Ljava.lang.String; @ 44eb7de8
11-10 22:16:38.186:ERROR / AndroidRuntime(3411):在com.example.display $ 2.onClick(display.java:124)
解决方案
使用方法的toArray()
的ArrayList<字符串> mStringList =新的ArrayList<字符串>();
mStringList.add(安);
mStringList.add(约翰福音);
[对象] mStringArray = mStringList.toArray();
的for(int i = 0; I< mStringArray.length;我++){
Log.d(字符串,(串)mStringArray [I]);
}
或者你可以做到这一点是这样的:(在其他的答案中提到)
的ArrayList<字符串> mStringList =新的ArrayList<字符串>();
mStringList.add(安);
mStringList.add(约翰福音);
的String [] mStringArray =新的String [mStringList.size()];
mStringArray = mStringList.toArray(mStringArray);
的for(int i = 0; I< mStringArray.length;我++){
Log.d(字符串,(串)mStringArray [I]);
}
http://developer.android.com/reference/java/util/ArrayList.html#toArray()
I have a ArrayList that contains values in the form [ann,john]. I want to convert this ArrayList into a String array in the form {"ann","john"}.
How should I do this?
My Android code:
final Button markabsent = (Button) findViewById(R.id.Button02);
markabsent.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Perform action on click
Toast.makeText(display.this,"You have marked the students absent",Toast.LENGTH_SHORT).show();
SparseBooleanArray checkedabsent = lView.getCheckedItemPositions();
for (int i = 0; i < arr2.length; i++)
{
if (checkedabsent.get(i))
{
items2.add(arr2[i]);
System.out.println(items2);
}
}
Log.d("", "items:");
for (String string : items2)
{
Log.d("string is", string);
}
}
});
My Logcat:
11-10 21:44:00.414: INFO/System.out(2316): [ann, john, ann]
11-10 21:44:00.414: DEBUG/(2316): items:
11-10 21:44:00.414: DEBUG/string is(2316): ann
11-10 21:44:00.414: DEBUG/string is(2316): john
I tried doing everything mentioned in the answers but my logcat just doesn't seem to imrove
Here is the one giving exceptions:
11-10 22:14:20.855: INFO/System.out(3322): [Ljava.lang.String;@44eb6ff0
11-10 22:16:38.186: ERROR/AndroidRuntime(3411): FATAL EXCEPTION: main
11-10 22:16:38.186: ERROR/AndroidRuntime(3411): java.lang.ClassCastException: [Ljava.lang.Object;
11-10 22:16:38.186: ERROR/AndroidRuntime(3411): at com.example.display$2.onClick(display.java:124)
11-10 22:16:38.186: ERROR/AndroidRuntime(3411): at android.view.View.performClick(View.java:2408)
11-10 22:16:38.186: ERROR/AndroidRuntime(3411): at android.view.View$PerformClick.run(View.java:8816)
11-10 22:16:38.186: ERROR/AndroidRuntime(3411): at android.os.Handler.handleCallback(Handler.java:587)
Here is one more:
11-10 22:14:20.875: DEBUG/string is(3322): ann
11-10 22:14:20.875: INFO/System.out(3322): [Ljava.lang.String;@44eb7720
11-10 22:14:20.875: INFO/System.out(3322): [Ljava.lang.String;@44eb7720
11-10 22:14:20.885: INFO/System.out(3322): [Ljava.lang.String;@44eb7720
11-10 22:14:20.895: DEBUG/string is(3322): john
11-10 22:14:20.895: INFO/System.out(3322): [Ljava.lang.String;@44eb7de8
11-10 22:16:38.186: ERROR/AndroidRuntime(3411): at com.example.display$2.onClick(display.java:124)
解决方案
Use the method "toArray()"
ArrayList<String> mStringList= new ArrayList<String>();
mStringList.add("ann");
mStringList.add("john");
Object[] mStringArray = mStringList.toArray();
for(int i = 0; i < mStringArray.length ; i++){
Log.d("string is",(String)mStringArray[i]);
}
or you can do it like this: (mentioned in other answers)
ArrayList<String> mStringList= new ArrayList<String>();
mStringList.add("ann");
mStringList.add("john");
String[] mStringArray = new String[mStringList.size()];
mStringArray = mStringList.toArray(mStringArray);
for(int i = 0; i < mStringArray.length ; i++){
Log.d("string is",(String)mStringArray[i]);
}
http://developer.android.com/reference/java/util/ArrayList.html#toArray()
相关推荐
最新文章