我是android数据库的新手。我正在创建一个关于数据库（youtube）的youtube教程的应用程序。
我遵循了所有内容，当我运行应用程序时会发生一些事情，应用程序崩溃。
当我首先运行应用程序时，一切正常，但是当我开始单击“创建”按钮时，应用程序崩溃了。
这是错误：
01-16 08:23:29.319: E/NativeCrypto(1015): ssl=0x598d7898 cert_verify_callback x509_store_ctx=0x56246ab8 arg=0x0
01-16 08:23:29.320: E/NativeCrypto(1015): ssl=0x598d7898 cert_verify_callback calling verifyCertificateChain authMethod=ECDHE_RSA
01-16 08:23:49.373: E/NativeCrypto(501): ssl=0x56b78cc0 cert_verify_callback x509_store_ctx=0x55bb2ab8 arg=0x0
01-16 08:23:49.373: E/NativeCrypto(501): ssl=0x56b78cc0 cert_verify_callback calling verifyCertificateChain authMethod=ECDHE_RSA
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): Object tried to add another callback
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): java.lang.Exception: Called by
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): at com.android.internal.policy.impl.keyguard.KeyguardUpdateMonitor.registerCallback(KeyguardUpdateMonitor.java:1107)
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): at com.android.internal.policy.impl.keyguard.KeyguardSelectorView.onResume(KeyguardSelectorView.java:369)
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): at com.android.internal.policy.impl.keyguard.KeyguardHostView.onScreenTurnedOn(KeyguardHostView.java:1118)
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): at com.android.internal.policy.impl.keyguard.KeyguardViewManager.onScreenTurnedOn(KeyguardViewManager.java:404)
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): at com.android.internal.policy.impl.keyguard.KeyguardViewMediator.handleNotifyScreenOn(KeyguardViewMediator.java:1767)
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): at com.android.internal.policy.impl.keyguard.KeyguardViewMediator.access$2300(KeyguardViewMediator.java:106)
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): at com.android.internal.policy.impl.keyguard.KeyguardViewMediator$4.handleMessage(KeyguardViewMediator.java:1413)
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): at android.os.Handler.dispatchMessage(Handler.java:107)
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): at android.os.Looper.loop(Looper.java:194)
01-16 08:24:32.711: E/KeyguardUpdateMonitor(501): at android.os.HandlerThread.run(HandlerThread.java:60)
01-16 08:24:32.794: E/AudioMTKHardware(136): setParameters() still have param.size() = 1, remain param = "screen_state=on"
01-16 08:24:55.102: E/BreakpadManager(7715): Breakpad init failed: Couldn't load fb_stl_shared from loader dalvik.system.PathClassLoader[DexPathList[[zip file "/system/framework/com.google.android.maps.jar", zip file "/system/app/Facebook.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]]: findLibrary returned null
01-16 08:24:55.811: E/NativeCrypto(1015): ssl=0x54f8f498 cert_verify_callback x509_store_ctx=0x56246ab8 arg=0x0
01-16 08:24:55.812: E/NativeCrypto(1015): ssl=0x54f8f498 cert_verify_callback calling verifyCertificateChain authMethod=ECDHE_RSA
01-16 08:24:56.111: E/WifiManager(7715): mWifiServiceMessenger == null
01-16 08:24:57.101: E/NativeCrypto(1015): ssl=0x5add3108 cert_verify_callback x509_store_ctx=0x56a4dab8 arg=0x0
01-16 08:24:57.102: E/NativeCrypto(1015): ssl=0x5add3108 cert_verify_callback calling verifyCertificateChain authMethod=ECDHE_RSA
01-16 08:24:58.626: E/NativeCrypto(1015): ssl=0x58094b58 cert_verify_callback x509_store_ctx=0x5479bab8 arg=0x0
01-16 08:24:58.626: E/NativeCrypto(1015): ssl=0x58094b58 cert_verify_callback calling verifyCertificateChain authMethod=RSA
01-16 08:25:08.008: E/AudioMTKHardware(136): setParameters() still have param.size() = 1, remain param = "screen_state=off"
我的代码也在这里：来自主要活动：
package com.example.studentdatabase;
import android.os.Bundle;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Color;
import android.graphics.Typeface;
import android.view.View;
import android.widget.EditText;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
public class MainActivity extends Activity {
String fname,lname,email;
SQLiteDatabase db;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
db= openOrCreateDatabase("MyDB1",MODE_PRIVATE,null);
db.execSQL("CREATE TABLE IF NOT EXISTS Student(fname VARCHAR,lname VARCHAR,email VARCHAR)");
}
public void Adddata(View view){
EditText editText1=(EditText) findViewById(R.id.firstname);
EditText editText2=(EditText) findViewById(R.id.lastname);
EditText editText3=(EditText) findViewById(R.id.email);
fname=editText1.getText().toString();
lname=editText2.getText().toString();
email=editText3.getText().toString();
db.execSQL("INSERT INTO Student VALUES('"+fname+"','"+lname+"','"+email+"')");
}
public void showdata(View view){
Cursor c=db.rawQuery("SELECT * from Student", null);
int count=c.getCount();
c.moveToFirst();
TableLayout tableLayout=new TableLayout(getApplicationContext());
tableLayout.setVerticalScrollBarEnabled(true);
TableRow tableRow;
TextView textView,textView1,textView2,textView3,textView4,textView5;
tableRow=new TableRow(getApplicationContext());
textView=new TextView(getApplicationContext());
textView.setText("Firstname");
textView.setTextColor(Color.RED);
textView.setTypeface(null,Typeface.BOLD);
textView.setPadding(20, 20, 20, 20);
tableRow.addView(textView);
textView4=new TextView(getApplicationContext());
textView4.setText("LastName");
textView4.setTextColor(Color.RED);
textView4.setTypeface(null,Typeface.BOLD);
textView4.setPadding(20, 20, 20, 20);
textView5=new TextView(getApplicationContext());
textView5.setText("LastName");
textView5.setTextColor(Color.RED);
textView5.setTypeface(null,Typeface.BOLD);
textView5.setPadding(20, 20, 20, 20);
tableRow.addView(tableRow);
for(Integer j=0; j < count; j++){
tableRow=new TableRow(getApplicationContext());
textView1=new TextView(getApplicationContext());
textView1.setText(c.getString(c.getColumnIndex("fname")));
textView2=new TextView(getApplicationContext());
textView2.setText(c.getString(c.getColumnIndex("lname")));
textView3=new TextView(getApplicationContext());
textView3.setText(c.getString(c.getColumnIndex("email")));
textView1.setPadding(20, 20,20, 20);
textView2.setPadding(20, 20,20, 20);
textView3.setPadding(20, 20,20, 20);
tableRow.addView(textView1);
tableRow.addView(textView2);
tableRow.addView(textView3);
tableLayout.addView(tableRow);
c.moveToNext();
}
setContentView(tableLayout);
db.close();
}
public void close(View view){
System.exit(0);
}
}
我的activity_main.xml：
<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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView2"
android:layout_below="@+id/textView2"
android:layout_marginTop="25dp"
android:text="last Name" />
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView1"
android:layout_below="@+id/textView1"
android:layout_marginTop="25dp"
android:text="Email" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="18dp"
android:layout_marginTop="27dp"
android:text="First Name" />
<EditText
android:id="@+id/firstname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/textView2"
android:layout_alignBottom="@+id/textView2"
android:layout_toRightOf="@+id/textView2"
android:ems="10" >
<requestFocus />
</EditText>
<EditText
android:id="@+id/lastname"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/textView1"
android:layout_alignBottom="@+id/textView1"
android:layout_alignLeft="@+id/firstname"
android:ems="10" />
<EditText
android:id="@+id/email"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/textView3"
android:layout_alignBottom="@+id/textView3"
android:layout_toRightOf="@+id/textView1"
android:ems="10" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView3"
android:layout_below="@+id/email"
android:layout_marginTop="28dp"
android:onClick="Adddata"
android:text="create" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/button1"
android:layout_alignBottom="@+id/button1"
android:layout_alignRight="@+id/email"
android:layout_marginRight="42dp"
android:onClick="showdata"
android:text="Show Table" />
<Button
android:id="@+id/button3"
andro
id:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/button1"
android:layout_below="@+id/button1"
android:layout_marginTop="33dp"
android:onClick="close"
android:text="Close" />
</RelativeLayout>
答案 0 :(得分：0)
您的activity_main.xml最后没有标记</RelativeLayout>。我不确定这是一个错字错误。添加它并重建应用程序。希望它能为你运行。
答案 1 :(得分：0)
更改Create Table行
db.execSQL("CREATE TABLE IF NOT EXISTS Student(fname TEXT,lname TEXT,email TEXT)");
SQLite使用动态类型。内容可以存储为INTEGER，REAL，TEXT，BLOB或NULL。 并检查db是否为null。