Question

我有一个方法可以将片段中的文本字段重置为＆＃34; ＆＃34 ;.当一切都在MainActivity中时，这很好用。问题是((EditText)v.findViewById(R.id.edAreaxml)).setText("");。

片段代码是：

public class DataEdit extends Fragment implements OnClickListener {

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.dataedit, container, false);
        Button btnResetForm = (Button) v.findViewById(R.id.btnResetFormxml);
        btnResetForm.setOnClickListener(this);
        return v;
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.btnResetFormxml:
            resetForm(v);
            break;
        }
    }
    public void resetForm(View v) {
        ((EditText) v.findViewById(R.id.edAreaxml)).setText(""); //THIS IS THE PROBLEM  
    }

XML：

<TableRow>  
        <TextView 
            android:layout_width="fill_parent" 
            android:layout_height="wrap_content" 
            android:text="Area">
        </TextView>    
        <EditText 
            android:layout_width="fill_parent" 
            android:layout_height="wrap_content" 
            android:id="@+id/edAreaxml">
        </EditText>            
</TableRow>

更新：根据答案1和3，进行了以下调整。还有一个问题。 LogCat输出位于底部。

public class DataEdit extends Fragment implements OnClickListener {
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.dataedit, container, false);
    Button btnResetForm = (Button)v.findViewById(R.id.btnResetFormxml);
    btnResetForm.setOnClickListener(this);
    //EditText edArea=(EditText)v.findViewById(R.id.edAreaxml);
    return v;
    }@Override
public void onClick(View v) {
        switch (v.getId()) {
    case R.id.btnResetFormxml:
            resetForm(v);
            break;
       }
    }
public void resetForm(View v) {             
        EditText edArea=(EditText)v.findViewById(R.id.edAreaxml);
        edArea.setText(" ");//PROBLEM IS HERE
    }
}

Logcat是：

03-21 09:35:20.735: E/Trace(1013): error opening trace file: No such file or directory (2)
03-21 09:35:21.795: D/gralloc_goldfish(1013): Emulator without GPU emulation detected.
03-21 09:35:22.425: I/Choreographer(1013): Skipped 48 frames!  The application may be doing too much work on its main thread.
03-21 09:35:25.805: I/Choreographer(1013): Skipped 71 frames!  The application may be doing too much work on its main thread.
03-21 09:35:28.254: D/AndroidRuntime(1013): Shutting down VM
03-21 09:35:28.254: W/dalvikvm(1013): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
03-21 09:35:28.294: E/AndroidRuntime(1013): FATAL EXCEPTION: main
03-21 09:35:28.294: E/AndroidRuntime(1013): java.lang.NullPointerException
03-21 09:35:28.294: E/AndroidRuntime(1013):     at net.JonesInc.streamwalker.DataEdit.resetForm(DataEdit.java:139)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at net.JonesInc.streamwalker.DataEdit.onClick(DataEdit.java:74)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at android.view.View.performClick(View.java:4084)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at android.view.View$PerformClick.run(View.java:16966)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at android.os.Handler.handleCallback(Handler.java:615)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at android.os.Handler.dispatchMessage(Handler.java:92)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at android.os.Looper.loop(Looper.java:137)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at android.app.ActivityThread.main(ActivityThread.java:4745)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at java.lang.reflect.Method.invokeNative(Native Method)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at java.lang.reflect.Method.invoke(Method.java:511)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
03-21 09:35:28.294: E/AndroidRuntime(1013):     at dalvik.system.NativeStart.main(Native Method)
03-21 09:35:32.204: I/Process(1013): Sending signal. PID: 1013 SIG: 9

Answer 1

尝试将本地变量初始化为：

EditText editText;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.dataedit, container, false);
    Button btnResetForm = (Button) v.findViewById(R.id.btnResetFormxml);
    btnResetForm.setOnClickListener(this);
    editText = (EditText) v.findViewById(R.id.edArea);
    return v;
}

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.btnResetFormxml:
            resetForm();
            break;
    }
}

public void resetForm() {             
    editText.setText(""); 
}

这样，您的resetForm方法就不需要View参数。

Answer 2

初始化EditText，如下所示，假设它属于dataedit.xml。

EditText ed;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.dataedit, container, false);
    ed =(EditText)v.findViewById(R.id.edArea);
    Button btnResetForm = (Button) v.findViewById(R.id.btnResetFormxml);
    btnResetForm.setOnClickListener(this);
    return v;
}

然后

@Override
public void onClick(View v) {
    switch (v.getId()) {
    case R.id.btnResetFormxml:
        resetForm(); // no need to pass v as a param
        // you could just have  ed.setText(""); here itself. no need for resetForm

        break;
    }
}

然后

public void resetForm() {             
    ed.setText("");
}

Answer 3

问题是 public void onClick(View v) 其中v是按钮。试着把

Button btnResetForm = (Button) v.findViewById(R.id.btnResetFormxml);
et = (EditText)v.findViewById(R.id.edArea);

并定义

EditText et;

作为片段的属性。之后你可以使用

public void resetForm(View v) {             
    et.setText("");  
}

在Android中的片段中设置文本

3 个答案: