由于类强制转换异常，我的应用程序崩溃了。我理解编辑文本上的类强制转换异常，但我无法解决这个问题。我在这个错误上做了很多尝试。请让它工作。 我的java代码：
public static final int targetVendorID = 1155;
public static final int targetProductID = 22336;
public UsbManager manager;
public UsbDeviceConnection usbDeviceConnection;
public UsbInterface usbInterfaceFound = null;
public UsbEndpoint endpointOut = null;
public UsbEndpoint endpointIn = null;
public UsbDevice usbdevice,device_details;
public UsbEndpoint listusbendpoint;
public LifeTest Life_Test_child;
HashMap<String, UsbDevice> devicelist= null;
int selectedendpoint;
static int Coil_No;
private static final int VID = 1155;
private static final int PID = 22336;
private static UsbDriver Usb_Driver_class;
public static UsbDriver USB_Driver_Child;
public static boolean Communication_Failed,Frame_Ok,Total_Frame_Decoded;
static byte[] Communication_Byte;
ActionBar actionbar;
UsbConnectionHandler connectionHandler;
Button clear,signin;
public EditText username_edt,password;
String i = "";
Intent i2;
String User_Name=null;
TextView title;
ByteBuffer buffer;
String Shared_username,shared_pass;
static byte[] sample;
static boolean Communication_Ok;
public static float []Wave_Form_Data=new float[1500];
public static float []Wave_Form_Data_1=new float[1500];
public static float Respsonse_Time,Drive_Voltage;
static int Sequence_No,Response_Time;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.loginpage);
actionbar = getActionBar();
actionbar.hide();
username_edt = (EditText)findViewById(R.id.edt_username);
password = (EditText)findViewById(R.id.edt_password);
signin = (Button)findViewById(R.id.btn_signin);
signin.setOnClickListener(new View.OnClickListener()
{
@SuppressWarnings("static-access")
@Override
public void onClick(View v)
{
{
Communication_Byte=new byte[1];
User_Name=username_edt.getText().toString();
if(User_Name.toLowerCase().equals("medequip") && password.getText().toString().equals("medequip"))
{
if(Check_Devices_Available()==true)
{
int Packet_Size = USB_Driver_Child.Data_In_End_Point.getMaxPacketSize();
Toast.makeText(Loginpage.this,""+Packet_Size, Toast.LENGTH_LONG).show();
if(!Receive.isAlive())
{
Receive.start();
}
else
Receive.stop();
Communication_Ok=false;
for(int i=0;(i<5 && Communication_Ok!=true);i++)
Send_Communication_Check_Command();
if(Communication_Ok)
Toast.makeText(Loginpage.this, "Communication Successfully Established", 1000).show();
else
Toast.makeText(Loginpage.this, "Communication Failure", 10000).show();
i2 = new Intent(Loginpage.this,TestsPage.class);
startActivity(i2);
}
}
else
{
Toast.makeText(Loginpage.this,"Invalid username and password", Toast.LENGTH_LONG).show();
}
}
}
});
clear = (Button)findViewById(R.id.btn_clear);
clear.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
username_edt.setText("");
password.setText("");
}
});
}
@SuppressLint("ShowToast") @SuppressWarnings({ "static-access" })
public boolean Check_Devices_Available()
{
Usb_Driver_class = new UsbDriver(this, connectionHandler, VID, PID);
if(USB_Driver_Child.Device_Exception==0)
{
if(USB_Driver_Child.USB_Device_Connection==null || USB_Driver_Child.Data_Out_End_Point==null)
return false;
Toast.makeText(Loginpage.this,"Device Found", 1000).show();
return true;
}
else if(USB_Driver_Child.Device_Exception==1)
{
Toast.makeText(Loginpage.this,"No Devices Attached ", Toast.LENGTH_LONG).show();
return false;
}
else if(USB_Driver_Child.Device_Exception==2)
{
Toast.makeText(Loginpage.this,"Device Found,But No End Points", Toast.LENGTH_LONG).show();
return false;
}
else if(USB_Driver_Child.Device_Exception==3)
{
Toast.makeText(Loginpage.this,"Unable to Open Device", Toast.LENGTH_LONG).show();
return false;
}
return false; //un known exception
}
Thread Receive = new Thread(new Runnable()
{
@SuppressWarnings("unused")
@Override
public void run()
{
Sequence_No=0;
buffer = ByteBuffer.allocate(1500);
sample = new byte[1500];
int Frame_Size;
UsbRequest request = new UsbRequest();
int i,j;
byte [] datarx=new byte[1];
char q;
while (true)
{
request.initialize(UsbDriver.USB_Device_Connection, UsbDriver.Data_In_End_Point);
request.queue(buffer, 1500);
if (UsbDriver.USB_Device_Connection.requestWait() == request)
{
sample=buffer.array();
for(i=0;i<1500;i++)
{
if(sample[i]=='&')
{
Communication_Ok=true;
break;
}
else if(sample[i]==0x03)
{
if(sample[0]==0x02)
Frame_Ok=true;
break;
}
}
if(Frame_Ok==true)
{
Frame_Ok=false;
if(sample[1]==1)
Coil_No=1;
else
Coil_No=2;
Response_Time= (int)(((sample[2]&0x00FF)<<8) + (sample[3]&0x00FF));
Total_Frame_Decoded=true;
sample = null;
}
}
}
}
});
private static void Send_Communication_Check_Command()
{
long i,j;
Communication_Byte[0]='&';
UsbDriver.USB_Device_Connection.bulkTransfer(UsbDriver.Data_Out_End_Point,Communication_Byte, 1, 0);
for(i=0;(i<1000 && Communication_Ok!=true) ;i++)
for(j=0;(j<1000 && Communication_Ok!=true);j++);
}
//Test_Name=1; For Drive Response Test
//Test_Name=2; For Drive Life Test
//Test_Name=3; To Stop test
public static void Send_Command_For_Drive_Response_Test(int Test_Name)
{
int i;
byte []Command_To_Transfer= new byte[5];
Communication_Ok=false;
for(i=0;i<5;i++)
{
Send_Communication_Check_Command();
if(Communication_Ok==true)
break;
}
if(Communication_Ok==true)
{
Command_To_Transfer[0]='*';
if(Test_Name==1)
{
Command_To_Transfer[1]=Command_To_Transfer[2]=(byte) 0xA1;
}
else if(Test_Name==2)
{
Command_To_Transfer[1]=Command_To_Transfer[2]=(byte) 0xA2;
}
else if(Test_Name==3)
{
Command_To_Transfer[1]=Command_To_Transfer[2]=(byte) 0xA3;
}
Command_To_Transfer[3]=0; //For Future Reference
Command_To_Transfer[4]='#';
UsbDriver.USB_Device_Connection.bulkTransfer(UsbDriver.Data_Out_End_Point,Command_To_Transfer, 5, 0);
Communication_Failed=true;
}
else
{
Communication_Failed=false;
}
}
这是mylogcat：
01-02 02:58:58.080: W/dalvikvm(9343): threadid=1: thread exiting with uncaught exception (group=0x41765700)
01-02 02:58:58.090: E/AndroidRuntime(9343): FATAL EXCEPTION: main
01-02 02:58:58.090: E/AndroidRuntime(9343): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.demo2c1testpanel/com.example.demo2c1testpanel.Loginpage}: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
01-02 02:58:58.090: E/AndroidRuntime(9343): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
01-02 02:58:58.090: E/AndroidRuntime(9343): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
01-02 02:58:58.090: E/AndroidRuntime(9343): at android.app.ActivityThread.access$600(ActivityThread.java:141)
01-02 02:58:58.090: E/AndroidRuntime(9343): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
01-02 02:58:58.090: E/AndroidRuntime(9343): at android.os.Handler.dispatchMessage(Handler.java:99)
01-02 02:58:58.090: E/AndroidRuntime(9343): at android.os.Looper.loop(Looper.java:137)
01-02 02:58:58.090: E/AndroidRuntime(9343): at android.app.ActivityThread.main(ActivityThread.java:5103)
01-02 02:58:58.090: E/AndroidRuntime(9343): at java.lang.reflect.Method.invokeNative(Native Method)
01-02 02:58:58.090: E/AndroidRuntime(9343): at java.lang.reflect.Method.invoke(Method.java:525)
01-02 02:58:58.090: E/AndroidRuntime(9343): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
01-02 02:58:58.090: E/AndroidRuntime(9343): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
01-02 02:58:58.090: E/AndroidRuntime(9343): at dalvik.system.NativeStart.main(Native Method)
01-02 02:58:58.090: E/AndroidRuntime(9343): Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
01-02 02:58:58.090: E/AndroidRuntime(9343): at com.example.demo2c1testpanel.Loginpage.onCreate(Loginpage.java:71)
01-02 02:58:58.090: E/AndroidRuntime(9343): at android.app.Activity.performCreate(Activity.java:5133)
01-02 02:58:58.090: E/AndroidRuntime(9343): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
01-02 02:58:58.090: E/AndroidRuntime(9343): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
这是我的XML文件：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<LinearLayout
android:id="@+id/linearLayout3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/linearLayout2"
android:layout_alignRight="@+id/linearLayout2"
android:layout_below="@+id/linearLayout2"
android:layout_marginTop="30dp" >
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:shadowColor="@color/text_shadow"
android:shadowDx="1"
android:shadowDy="1"
android:shadowRadius="2"
android:text="@string/password"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="@color/light_font" />
<EditText
android:id="@+id/edt_password"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:gravity="center"
android:hint="@string/password_hint"
android:inputType="textPassword" >
<requestFocus />
</EditText>
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout2"
android:layout_width="250dp"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/linearLayout1"
android:layout_alignRight="@+id/linearLayout1"
android:layout_below="@+id/linearLayout1"
android:layout_marginTop="111dp" >
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:shadowColor="@color/text_shadow"
android:shadowDx="1"
android:shadowDy="1"
android:shadowRadius="2"
android:text="@string/user_name"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="@color/light_font" />
<EditText
android:id="@+id/edt_username"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="center"
android:hint="@string/user_name_hint" />
</LinearLayout>
<LinearLayout
android:id="@+id/linearLayout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:orientation="vertical" >
<TextView
android:id="@+id/textView1"
android:layout_width="570dp"
android:layout_height="wrap_content"
android:ellipsize="marquee"
android:fadingEdge="horizontal"
android:gravity="center"
android:marqueeRepeatLimit="marquee_forever"
android:scrollHorizontally="true"
android:singleLine="true"
android:text="@string/Login_title"
android:textAppearance="?android:attr/textAppearanceLarge" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/linearLayout3"
android:layout_alignRight="@+id/linearLayout3"
android:layout_below="@+id/linearLayout3"
android:layout_marginTop="60dp" >
<Button
android:id="@+id/btn_clear"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="0.36"
android:shadowRadius="2"
android:text="@string/clear"
/>
<Button
android:id="@+id/btn_signin"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="0.35"
android:text="@string/signin" />
</LinearLayout>
<ImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_toRightOf="@+id/linearLayout4"
android:src="@drawable/logo" />
</RelativeLayout>
答案 0 :(得分：0)
您似乎在布局文件（R.id.edt_username）中将R.id.edt_password或R.layout.loginpage（或两者）声明为Button。将其更改为EditText。