Android:如何引用EditText视图

时间:2013-01-09 12:33:47

标签: android view android-edittext textview

我有以下布局:

<TextView 
    android:id = "@+id/HRNoninTextBox"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"
    android:layout_below="@+id/exitbtn" 
    android:text="Heart Rate"
    android:textSize = "20sp"/>
<EditText 
    android:id="@+id/labelNoninHeartRate" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="00" 
    android:layout_alignParentRight="true">                         
</EditText>

从代码我引用这些视图,以这种方式形成我的活动:

TextView tvHr= (TextView)findViewById(R.id.HRNoninTextBox);

EditText etHr = (EditText)findViewById(R.id.labelNoninHeartRate);

第一个不会产生任何错误,而第二个语句会产生以下错误:

 01-09 13:24:57.599: W/dalvikvm(28816): threadid=1: thread exiting with uncaught exception (group=0x4001e578)
01-09 13:24:57.619: E/AndroidRuntime(28816): FATAL EXCEPTION: main
01-09 13:24:57.619: E/AndroidRuntime(28816): java.lang.RuntimeException: Unable to start activity ComponentInfo{aid.assistant233/aid.assistant233.AidAssistant233Activity}: java.lang.ClassCastException: android.widget.TextView
01-09 13:24:57.619: E/AndroidRuntime(28816):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at android.app.ActivityThread.access$1500(ActivityThread.java:117)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at android.os.Handler.dispatchMessage(Handler.java:99)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at android.os.Looper.loop(Looper.java:130)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at android.app.ActivityThread.main(ActivityThread.java:3691)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at java.lang.reflect.Method.invokeNative(Native Method)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at java.lang.reflect.Method.invoke(Method.java:507)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at dalvik.system.NativeStart.main(Native Method)
01-09 13:24:57.619: E/AndroidRuntime(28816): Caused by: java.lang.ClassCastException: android.widget.TextView
01-09 13:24:57.619: E/AndroidRuntime(28816):    at aid.assistant233.AidAssistant233Activity.onCreate(AidAssistant233Activity.java:331)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-09 13:24:57.619: E/AndroidRuntime(28816):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)
01-09 13:24:57.619: E/AndroidRuntime(28816):    ... 11 more

哪里可能出现问题?

1 个答案:

答案 0 :(得分:0)

Step1:您可以按照所有人的说法清理/构建项目。但如果您没有通过clean / build解决问题,请检查我的step2。

<强>步骤:2: 我当然不是,但你可以再次查看你的xml文件吗?

如果您有两个具有相同ID的元素,也可能发生这种情况:

<TextView android:text="Hello Ahmedabad:" 
    android:id="@+id/txtahmedabad" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content">
</TextView>

<EditText android:layout_height="wrap_content"
    android:layout_width="fill_parent" 
    android:id="@+id/txtahmedabad" 
    android:text="">
</EditText>

如果是这样,那么给他们不同的ID - 它可以选择第一个(TextView),显然无法将其转换为EditText

希望它会对你有所帮助。