一个简单的Android程序，用于输入文本（在Edittext中）并复制到clipboard（在点击复制按钮后）...
打开时崩溃，我缺少什么？
import android.content.ClipData;
import android.content.ClipboardManager;
import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public abstract class MainActivity extends AppCompatActivity implements View.OnClickListener {
EditText e1;
Button b1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
e1 = (EditText) findViewById(R.id.editText);
b1 = (Button) findViewById(R.id.button);
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
copytext(view);
}
});
}
public void copytext(View view) {
ClipboardManager clipboard = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
ClipData clip = ClipData.newPlainText("Copied Text", (CharSequence) e1);
clipboard.setPrimaryClip(clip);
}
}
我也试过使用以下但没有成功：
ClipData clip = ClipData.newPlainText("Copied Text", String.valueOf(e1));
我的xml，
<?xml version="1.0" encoding="utf-8"?>
<android.widget.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"
tools:context="com.quickclip.panky.quickclip.MainActivity">
<EditText
android:id="@+id/editText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="30dp"
android:ems="100"
android:inputType="textAutoCorrect"
android:text="Your Voice Input" />
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/editText"
android:layout_centerHorizontal="true"
android:onClick="copytext"
android:text="Copy" />
</android.widget.RelativeLayout>
这是log cat
01-31 15:16:19.168 7127-7127/? I/art: Late-enabling -Xcheck:jni
01-31 15:16:19.458 7127-7127/? W/System: ClassLoader referenced unknown path: /data/app/com.quickclip.panky.quickclip-2/lib/arm64
01-31 15:16:19.459 7127-7127/? D/ActivityThread: installProvider: context.getPackageName()=com.quickclip.panky.quickclip
01-31 15:16:19.463 7127-7127/? I/InstantRun: starting instant run server: is main process
01-31 15:16:19.474 7127-7127/? D/AndroidRuntime: Shutting down VM
01-31 15:16:19.475 7127-7127/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.quickclip.panky.quickclip, PID: 7127
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.quickclip.panky.quickclip/com.quickclip.panky.quickclip.MainActivity}: java.lang.InstantiationException: java.lang.Class<com.quickclip.panky.quickclip.MainActivity> cannot be instantiated
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2536)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2699)
at android.app.ActivityThread.access$1000(ActivityThread.java:196)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1534)
at android.os.Handler.dispatchMessage(Handler.java:111)
at android.os.Looper.loop(Looper.java:207)
at android.app.ActivityThread.main(ActivityThread.java:5857)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1026)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:887)
Caused by: java.lang.InstantiationException: java.lang.Class<com.quickclip.panky.quickclip.MainActivity> cannot be instantiated
at java.lang.Class.newInstance(Native Method)
at android.app.Instrumentation.newActivity(Instrumentation.java:1078)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2526)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2699)
at android.app.ActivityThread.access$1000(ActivityThread.java:196)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1534)
at android.os.Handler.dispatchMessage(Handler.java:111)
at android.os.Looper.loop(Looper.java:207)
at android.app.ActivityThread.main(ActivityThread.java:5857)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1026)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:887)
01-31 15:16:19.515 7127-7127/? I/Process: Sending signal. PID: 7127 SIG: 9
我是android编程的新手：）
答案 0 :(得分：2)
<强>结构
ClipData newPlainText (CharSequence label,CharSequence text)
第二个参数 CharSequence: The actual text in the clip.
<强>最后
ClipData clip = ClipData.newPlainText("Copied Text", e1.getText().toString());
<强> FYI
abstract kEYWORD。onCreate部分
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
copyMethod();
}
});
}
和
public void copytext(View view)
{
copyMethod();
}
public void copyMethod()
{
ClipboardManager clipboard = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
ClipData clip = ClipData.newPlainText("Copied Text", (CharSequence) e1.getText().toString());
clipboard.setPrimaryClip(clip);
}
答案 1 :(得分：2)
没有任何日志，也可能有其他错误，但这里有一个：
您无法将EditText（一个UI对象）强制转换为CharSequence。相反，这样做：
public void copytext(View view) {
ClipboardManager clipboard = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
ClipData clip = ClipData.newPlainText("Copied Text", e1.getText().toString());
clipboard.setPrimaryClip(clip);
}
答案 2 :(得分：2)
只需从活动中删除抽象，它就会导致java.lang.InstantiationException:
替换
public abstract class MainActivity extends AppCompatActivity implements View.OnClickListener
并实施
public class MainActivity extends AppCompatActivity implements View.OnClickListener
通过覆盖onclick方法实现接口
@Override
public void onClick(View v) {
}