我使用設(shè)計(jì)模式屏幕設(shè)計(jì)創(chuàng)建了這個(gè)屏幕。這個(gè)問(wèn)題基于 XML 的底部，帶有 btnSave 按鈕。在我的 Java 類中，我試圖創(chuàng)建一個(gè)onClickListener類似的import android.database.sqlite.SQLiteDatabase;import android.support.v7.app.AlertDialog;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.TextView;public class ftpDetails extends AppCompatActivity{private TextView txtServer;private TextView txtFolder;private TextView txtUsername;private TextView txtPassword;@Overrideprotected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_ftp_details); setTitle(R.string.ftpTitle); txtServer = (TextView) findViewById(R.id.txtServer); txtFolder = (TextView) findViewById(R.id.txtFolder); txtUsername = (TextView) findViewById(R.id.txtUsername); txtPassword = (TextView) findViewById(R.id.txtPassword);findViewById(R.id.btnSave).setOnClickListener(null); // Check that all text boxes have a value in them if (txtServer.getText().length() == 0) { // MESSAGE BOX AlertDialog.Builder msg = new AlertDialog.Builder(this); msg.setTitle("Enter Server"); msg.setMessage("Please enter a server address."); msg.setPositiveButton("OK", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // Leave this blank, this will mean nothing happens, the msg just disappears } }); }但是，當(dāng)我將應(yīng)用程序 (Shift + F9) 調(diào)試到我連接的設(shè)備 (OnePlus 6T) 時(shí)，沒有一個(gè)斷點(diǎn)被命中。此外，當(dāng)我按下按鈕并且文本框?yàn)榭瞻讜r(shí)，不會(huì)顯示消息警報(bào)。我做錯(cuò)了什么嗎？我嘗試使用 XMLonClick:屬性，但結(jié)果相同，并且在設(shè)計(jì)模式下設(shè)置了相同的屬性，但同樣沒有任何變化。
4 回答
GCT1015
TA貢獻(xiàn)1827條經(jīng)驗(yàn) 獲得超4個(gè)贊
你為什么使用這樣的點(diǎn)擊監(jiān)聽器：findViewById(R.id.btnSave).setOnClickListener(null);
改為這樣做：
findViewById(R.id.btnSave).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//put all your textView logic here
}
});
白衣非少年
TA貢獻(xiàn)1155條經(jīng)驗(yàn) 獲得超0個(gè)贊
更改此行：
findViewById(R.id.btnSave).setOnClickListener(null);
進(jìn)入
findViewById(R.id.btnSave).setOnClickListener(btnSaveListener);
onCreate并從方法中刪除以下行。
然后創(chuàng)建btnSaveListener如下：
private View.OnClickListener btnSaveListener =new View.OnClickListener() {
@Override
public void onClick(View v) {
// here goes all the code belove the line you change in the method `onCreate`
}
};
慕蓋茨4494581
TA貢獻(xiàn)1850條經(jīng)驗(yàn) 獲得超11個(gè)贊
最后，這不是我如何設(shè)置聽眾的問(wèn)題。
將活動(dòng)調(diào)用從我的MainActivity啟動(dòng)類更改為StartActivity意味著OnCreate代碼被正確調(diào)用。
慕容森
TA貢獻(xiàn)1853條經(jīng)驗(yàn) 獲得超18個(gè)贊
你的按鈕點(diǎn)擊監(jiān)聽器實(shí)現(xiàn)是錯(cuò)誤的，試試這樣：
findViewById(R.id.action_ask).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// Check that all text boxes have a value in them
if (txtServer.getText().length() == 0)
{
// MESSAGE BOX
AlertDialog.Builder msg = new AlertDialog.Builder(this);
msg.setTitle("Enter Server");
msg.setMessage("Please enter a server address.");
msg.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// Leave this blank, this will mean nothing happens, the msg just disappears
}
});
}
if (txtFolder.getText().length() == 0)
{
// MESSAGE BOX
AlertDialog.Builder msg = new AlertDialog.Builder(this);
msg.setTitle("Enter Folder");
msg.setMessage("Please enter a folder to use.");
msg.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// Leave this blank, this will mean nothing happens, the msg just disappears
}
});
}
if (txtUsername.getText().length() == 0)
{
// MESSAGE BOX
AlertDialog.Builder msg = new AlertDialog.Builder(this);
msg.setTitle("Enter Username");
msg.setMessage("Please enter your username.");
msg.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// Leave this blank, this will mean nothing happens, the msg just disappears
}
});
}
if (txtPassword.getText().length() == 0)
{
// MESSAGE BOX
AlertDialog.Builder msg = new AlertDialog.Builder(this);
msg.setTitle("Enter Server");
msg.setMessage("Please enter a your password.");
msg.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// Leave this blank, this will mean nothing happens, the msg just disappears
}
});
}
}
});
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