我有两个旋转器。一个用于高度单位，另一个用于重量单位。在我的布局上，高度和重量都有两个edittext字段。我想在选择某个微调项目时隐藏一个。我是新手，所以任何帮助都会非常感激。提前谢谢。
即。如果在高度微调器CM中被选中，我想隐藏第二个高度的edittext字段。
我的微调器值是我的字符串文件中的数组。
这是我的代码：
的strings.xml
<string name="weight_kg">KG</string>
<string name="weight_lb">LB</string>
<string name="weight_st_lb">ST + LB</string>
<string name="height_ft_in">FT + IN</string>
<string name="height_cm">CM</string>
<string-array name="weight_spinner">
<item>@string/weight_kg</item>
<item>@string/weight_lb</item>
<item>@string/weight_st_lb</item>
</string-array>
<string-array name="height_spinner">
<item>@string/height_cm</item>
<item>@string/height_ft_in</item>
</string-array>
Bmi.java
package com.Health.Kicks.Calcs.Admob;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.support.v4.app.NavUtils;
import android.annotation.TargetApi;
import android.os.Build;
public class Bmi extends Activity {
EditText height1, weight1, height, weight;
Spinner height_spinner, weight_spinner;
String heightInputString, weightInputString;
Button calculatebmi;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bmi);
// Show the Up button in the action bar.
setupActionBar();
setupSpinners();
}
void setupSpinners() {
height_spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
if (position == 0){
height1.setVisibility(View.GONE);
} else {
height1.setVisibility(View.VISIBLE);
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
/**
* Set up the {@link android.app.ActionBar}, if the API is available.
*/
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
private void setupActionBar() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
getActionBar().setDisplayHomeAsUpEnabled(true);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.bmi, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// This ID represents the Home or Up button. In the case of this
// activity, the Up button is shown. Use NavUtils to allow users
// to navigate up one level in the application structure. For
// more details, see the Navigation pattern on Android Design:
//
// http://developer.android.com/design/patterns/navigation.html#up-vs-back
//
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
}
logcat的：
09-07 09:19:55.366: E/AndroidRuntime(1056): FATAL EXCEPTION: main
09-07 09:19:55.366: E/AndroidRuntime(1056): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.Health.Kicks.Calcs.Admob/com.Health.Kicks.Calcs.Admob.Bmi}: java.lang.NullPointerException
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread.access$600(ActivityThread.java:141)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.os.Handler.dispatchMessage(Handler.java:99)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.os.Looper.loop(Looper.java:137)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread.main(ActivityThread.java:5103)
09-07 09:19:55.366: E/AndroidRuntime(1056): at java.lang.reflect.Method.invokeNative(Native Method)
09-07 09:19:55.366: E/AndroidRuntime(1056): at java.lang.reflect.Method.invoke(Method.java:525)
09-07 09:19:55.366: E/AndroidRuntime(1056): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
09-07 09:19:55.366: E/AndroidRuntime(1056): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
09-07 09:19:55.366: E/AndroidRuntime(1056): at dalvik.system.NativeStart.main(Native Method)
09-07 09:19:55.366: E/AndroidRuntime(1056): Caused by: java.lang.NullPointerException
09-07 09:19:55.366: E/AndroidRuntime(1056): at com.Health.Kicks.Calcs.Admob.Bmi.setupSpinners(Bmi.java:35)
09-07 09:19:55.366: E/AndroidRuntime(1056): at com.Health.Kicks.Calcs.Admob.Bmi.onCreate(Bmi.java:30)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.Activity.performCreate(Activity.java:5133)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
09-07 09:19:55.366: E/AndroidRuntime(1056): ... 11 more
09-07 09:19:55.366: E/AndroidRuntime(1056): FATAL EXCEPTION: main
09-07 09:19:55.366: E/AndroidRuntime(1056): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.Health.Kicks.Calcs.Admob/com.Health.Kicks.Calcs.Admob.Bmi}: java.lang.NullPointerException
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread.access$600(ActivityThread.java:141)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.os.Handler.dispatchMessage(Handler.java:99)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.os.Looper.loop(Looper.java:137)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread.main(ActivityThread.java:5103)
09-07 09:19:55.366: E/AndroidRuntime(1056): at java.lang.reflect.Method.invokeNative(Native Method)
09-07 09:19:55.366: E/AndroidRuntime(1056): at java.lang.reflect.Method.invoke(Method.java:525)
09-07 09:19:55.366: E/AndroidRuntime(1056): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
09-07 09:19:55.366: E/AndroidRuntime(1056): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
09-07 09:19:55.366: E/AndroidRuntime(1056): at dalvik.system.NativeStart.main(Native Method)
09-07 09:19:55.366: E/AndroidRuntime(1056): Caused by: java.lang.NullPointerException
09-07 09:19:55.366: E/AndroidRuntime(1056): at com.Health.Kicks.Calcs.Admob.Bmi.setupSpinners(Bmi.java:35)
09-07 09:19:55.366: E/AndroidRuntime(1056): at com.Health.Kicks.Calcs.Admob.Bmi.onCreate(Bmi.java:30)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.Activity.performCreate(Activity.java:5133)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
09-07 09:19:55.366: E/AndroidRuntime(1056): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
09-07 09:19:55.366: E/AndroidRuntime(1056): ... 11 more
答案 0 :(得分：0)
为每个微调器设置setOnItemSelectedListener以便为您完成此工作...
即。如果在高度微调器CM中被选中，我想隐藏第二个高度的edittext字段。
更新：您还需要设置EditTexts，Spinner和＆amp;按钮
EditText height1, weight1, height, weight;
Spinner height_spinner, weight_spinner;
String heightInputString, weightInputString;
Button calculatebmi;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bmi);
// set your class members as they start out null.
// do this for all of them
height1 = (EditText) findViewById(R.id.idofheight1inxml);
height_spinner = (Spinner) findViewById(R.id.idofheightspinnerinxml);
....
// Show the Up button in the action bar.
setupActionBar();
setupSpinners();
}
void setupSpinners(){
height_spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
//I.E. if in the height spinner CM is selected I would like to hide the second height edittext field.
// I'm not sure if this is meant to be "height1" or "height"
if (position == 0){
height.setVisibility(View.GONE);
} else {
height.setVisibility(View.VISIBLE);
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
// if you want to add similar logic for weight spinner, do that with this :
weight_spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
// put your code here for weight spinner
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}