>我在下面给出了我的代码。我只想在 android 中创建一个自定义对话框。每当我单击按钮时,它都会显示一个自定义对话框.我创建了一个 xml"alert.xml".单击按钮后,我将显示字符串中的内容.xml
public class TriangleActivity extends Activity implements View.OnClickListener{
/** Called when the activity is first created. */
private Button bt;
private Dialog dialog;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
bt=(Button) findViewById(R.id.button1);
bt.setOnClickListener(this);
//Context mContext = getApplicationContext();
dialog = new Dialog(TriangleActivity.this);
dialog.setContentView(R.layout.alert);
dialog.setTitle("This is my custom dialog box");
TextView t=(TextView) findViewById(R.id.tv1);
t.setText(getString(R.string.h));
}
public void onClick(View v)
{
dialog.show();
}
}
主.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
>
<Button
android:id="@+id/button1"
android:layout_width="60dp"
android:layout_height="60dp"
/>
</LinearLayout>
警报.xml
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scrollbars="vertical" >
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scrollbarAlwaysDrawVerticalTrack="true" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tv1" >
</TextView>
</LinearLayout>
</ScrollView>
字符串.xml
<?xml version="1.0" encoding="utf-8"?>I am getting
<resources>
<string name="hello">Hello World, TriangleActivity!</string>
<string name="app_name">Triangle</string>
<string name="h">The Royal Society of Chemistry’s interactive periodic table which </string>
</resources>
使用它来查找文本视图:
TextView t=(TextView)dialog.findViewById(R.id.tv1);
TextView t=(TextView)dialog.findViewById(R.id.tv1);
这是你的解决方案伙计
修改您的文本视图初始化..因为它找不到对话框视图。所以这样做——
TextView t=(TextView)dialog.findViewById(R.id.tv1);
希望这对您有所帮助..
); 是抛出异常 NullPointerException,这意味着 t 或 getString(R.string.h) 为空。t 可能为空,如果 main.xml 没有 id 为 @+id/tv1 的文本视图。
text = (TextView)findviewByid(R.id.text1);