Java 无法对我的Android应用程序使用putExtra()和getExtras()
我想将电影名称从MainActivity(ListView)发送到SongActivity。这就是我尝试过的 MainActivity.javaJava 无法对我的Android应用程序使用putExtra()和getExtras(),java,android,android-intent,Java,Android,Android Intent,我想将电影名称从MainActivity(ListView)发送到SongActivity。这就是我尝试过的 MainActivity.java public class MainActivity extends Activity{ Activity context; HttpPost httppost; StringBuffer buffer; HttpResponse response; HttpClient httpclient; ProgressDial
public class MainActivity extends Activity{
Activity context;
HttpPost httppost;
StringBuffer buffer;
HttpResponse response;
HttpClient httpclient;
ProgressDialog pd;
CustomAdapter adapter;
ListView listProduct;
ArrayList<String> records;
protected void onCreate(Bundle savedInstanceState) {
//TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context=this;
records=new ArrayList<String>();
listProduct=(ListView)findViewById(R.id.product_list);
adapter=new CustomAdapter(context, R.layout.list_item,R.id.pro_name, records);
listProduct.setAdapter(adapter);
listProduct.setOnItemClickListener(new OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> arg0, View v, int position, long id){
String sText = ((TextView) v).getText().toString();
Intent songIntent = new Intent(getApplicationContext(), SongActivity.class);
songIntent.putExtra("movie_name", sText );
startActivity(songIntent);
}
});
}
package com.example.telugump3;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
public class SongActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.song_activity);
TextView tt = (TextView)findViewById(R.id.testing);
Intent iin= getIntent();
Bundle b = iin.getExtras();
if(b!=null)
{
String j =(String) b.get("movie_name");
tt.setText(j);
}
}
logcat
03-22 17:17:20.949: E/IMGSRV(22747): :0: PVRDRMOpen: TP3, ret = 46
03-22 17:17:20.959: E/IMGSRV(22747): :0: PVRDRMOpen: TP3, ret = 50
03-22 17:17:20.959: E/IMGSRV(22747): :0: PVRDRMOpen: TP3, ret = 51
03-22 17:17:20.959: E/IMGSRV(22747): :0: PVRDRMOpen: TP3, ret = 51
03-22 17:17:20.959: E/IMGSRV(22747): :0: PVRDRMOpen: TP3, ret = 51
03-22 17:17:20.969: E/IMGSRV(22747): :0: PVRDRMOpen: TP3, ret = 53
03-22 17:17:20.999: D/OpenGLRenderer(22747): Enabling debug mode 0
03-22 17:17:23.149: I/dalvikvm(22747): Total arena pages for JIT: 11
03-22 17:17:23.149: I/dalvikvm(22747): Total arena pages for JIT: 12
03-22 17:17:23.149: I/dalvikvm(22747): Total arena pages for JIT: 13
03-22 17:17:23.149: I/dalvikvm(22747): Total arena pages for JIT: 14
03-22 17:17:23.149: I/dalvikvm(22747): Total arena pages for JIT: 15
03-22 17:17:23.149: I/dalvikvm(22747): Total arena pages for JIT: 16
03-22 17:17:23.159: I/dalvikvm(22747): Total arena pages for JIT: 17
03-22 17:17:23.159: I/dalvikvm(22747): Total arena pages for JIT: 18
03-22 17:17:23.159: I/dalvikvm(22747): Total arena pages for JIT: 19
03-22 17:17:23.159: I/dalvikvm(22747): Total arena pages for JIT: 20
03-22 17:17:25.289: D/AndroidRuntime(22747): Shutting down VM
03-22 17:17:25.289: W/dalvikvm(22747): threadid=1: thread exiting with uncaught exception (group=0x430ef140)
03-22 17:17:25.299: E/AndroidRuntime(22747): FATAL EXCEPTION: main
03-22 17:17:25.299: E/AndroidRuntime(22747): Process: com.example.telugump3, PID: 22747
03-22 17:17:25.299: E/AndroidRuntime(22747): java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.TextView
03-22 17:17:25.299: E/AndroidRuntime(22747): at com.example.telugump3.MainActivity$1.onItemClick(MainActivity.java:51)
03-22 17:17:25.299: E/AndroidRuntime(22747): at android.widget.AdapterView.performItemClick(AdapterView.java:299)
03-22 17:17:25.299: E/AndroidRuntime(22747): at android.widget.AbsListView.performItemClick(AbsListView.java:1158)
03-22 17:17:25.299: E/AndroidRuntime(22747): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2949)
03-22 17:17:25.299: E/AndroidRuntime(22747): at android.widget.AbsListView$3.run(AbsListView.java:3683)
03-22 17:17:25.299: E/AndroidRuntime(22747): at android.os.Handler.handleCallback(Handler.java:733)
03-22 17:17:25.299: E/AndroidRuntime(22747): at android.os.Handler.dispatchMessage(Handler.java:95)
03-22 17:17:25.299: E/AndroidRuntime(22747): at android.os.Looper.loop(Looper.java:149)
03-22 17:17:25.299: E/AndroidRuntime(22747): at android.app.ActivityThread.main(ActivityThread.java:5257)
03-22 17:17:25.299: E/AndroidRuntime(22747): at java.lang.reflect.Method.invokeNative(Native Method)
03-22 17:17:25.299: E/AndroidRuntime(22747): at java.lang.reflect.Method.invoke(Method.java:515)
03-22 17:17:25.299: E/AndroidRuntime(22747): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
03-22 17:17:25.299: E/AndroidRuntime(22747): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609)
03-22 17:17:25.299: E/AndroidRuntime(22747): at dalvik.system.NativeStart.main(Native Method)
03-22 17:17:27.259: I/Process(22747): Sending signal. PID: 22747 SIG: 9
我已尝试删除putExtra(),SongActivity启动得非常完美。但是如果我使用putExtra(),当我单击ListView中的任何项目时,应用程序就会崩溃。我只需要单击项目的文本,以便在其他活动中使用它。尝试:String j=(String)b.getString(“movie_name”)代码>
java.lang.ClassCastException:android.widget.RelativeLayout不能强制转换为android.widget.TextView
您正在将RelativeLayout
转换为TextView
。检查您的findViewById()
调用,如果存在这样的强制转换,或者您在发送时使用了错误的id
,请执行此操作
intent.putExtra("message", message);
在收到
Intent intent = getIntent();
String message = intent.getStringExtra("message");
onItemClick的参数v是listview项的根布局。这不是你的文本视图。所以你必须修改如下
//String sText = ((TextView) v).getText().toString();
String sText = ((TextView) v.findViewById(R.id.[your TextView id])).getText().toString();
Ops,你对put或get EXTRACT没有问题,请注意错误
您的问题是,单击的目标是一个布局,而布局不能强制转换到TextView
java.lang.ClassCastException:android.widget.RelativeLayout不能强制转换为android.widget.TextView
在com.example.telugump3.MainActivity$1.onItemClick(MainActivity.java:51)
正如您所看到的,您的问题与额外的内容无关,但您知道该在哪里查看,所以让我们来看看您如何在<代码>主程序< /代码>
中声明您的项目适配器。
adapter = new CustomAdapter(context, R.layout.list_item,R.id.pro_name, records);
我假设参数如下:上下文、布局id、文本视图id、数据集。因此,项目布局中TextView
的id是R.id.pro\u name
现在让我们看看在您的侦听器中发生了什么:
@Override
public void onItemClick(AdapterView<?> arg0, View v, int position, long id){
// arg0 is the ListView
// v is the whole item layout
String sText = ((TextView) v).getText().toString();
// you assumed that the whole layout was a TextView
// ...
}
为什么这么糟糕?你必须在两个地方写R.id.pro\u name
。你将应用程序的表示层和模型层混合在一起——你不是在问数据集,而是在问已经依赖数据集的人
选项2)前进之路
String sText = adapter.getItem(position).toString();
您请求的数据与列表视图使用的适配器相同。我已更新。请告诉我它是否有效。问题在于布局,先生……问题已解决……无论如何,感谢您的帮助;)谢谢你,先生……你帮了我很多忙!将listitem布局从RelativeLayout更改为TextView…成功了!!当它工作的时候,这是一个坏习惯。您有一个完美的字符串数据集,可以使用(records.get(position)
),这些字符串被送入列表视图使用的适配器(adapter.getItem(position).toString()
)中,但您可以选择从文本视图(表示层)中选择数据。
String sText = adapter.getItem(position).toString();