Question

我的学校有一个项目，我从EditText获取值并对其进行计算，问题是我无法从EditText检索值。这是我的代码：

public class MainActivity extends ActionBarActivity {

    int valuearg1, valuearg2;
    float valuearg3;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        EditText arg1 = (EditText) findViewById(R.id.editArg1);

        EditText arg2 = (EditText) findViewById(R.id.editArg2);
        EditText arg3 = (EditText) findViewById(R.id.editArg3);
        try {
            String arg1value = arg1.getText().toString();
            valuearg1 = Integer.parseInt(arg1value);
            String arg2value = arg2.getText().toString();
            valuearg2 = Integer.parseInt(arg2value);
            String arg1value3 = arg3.getText().toString();
            valuearg3 = Float.parseFloat(arg1value3);

            final AlertDialog.Builder builder1 = new AlertDialog.Builder(this);
            builder1.setMessage("Values are :" + valuearg1 + "\n"
                    + valuearg2 + "\n"
                    + valuearg3)
                    .setNegativeButton(R.string.okay, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialogInterface, int i) {
                            Toast.makeText(MainActivity.this, "test toast", Toast.LENGTH_LONG).show();
                        }
                    });
            Button button = (Button) findViewById(R.id.button);
            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    builder1.show();
                }
            });
        }
        catch (Exception e)
        {
            Toast.makeText(this, "bug detected", Toast.LENGTH_LONG).show();
        }
}

提前感谢您的帮助。

Answer 1

尝试插入

builder1.setMessage

在OnClick块中。

Answer 2

当然你不能，你正试图在它们被创造之后获得它们的价值。你实际想要做的是将对话创建到一个不同的函数，而不是onCreate（）。

Answer 3

创建活动后会立即读取这些值，因为您正在onCreate()中读取值。你应该做的是删除所有计算代码形式onCreate()，并简单地声明arg1，arg2，arg3和按钮。然后该按钮的onClick()应调用compute（）或某些此类函数，在单击按钮后读取这些EditText中的值，计算答案然后显示。

Answer 4

当您获取值时，EditText框中没有值，因为您在创建活动时获得了值。

您需要在调用按钮单击事件时获取值。

这样的事情会起作用：

public class MainActivity extends ActionBarActivity {
int valuearg1, valuearg2;
float valuearg3;

EditText arg1, arg2, arg3;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    arg1 = (EditText) findViewById(R.id.editArg1);
    arg2 = (EditText) findViewById(R.id.editArg2);
    arg3 = (EditText) findViewById(R.id.editArg3);
    try {


        final AlertDialog.Builder builder1 = new AlertDialog.Builder(this);
        builder1.setMessage("Values are :" + valuearg1 + "\n"
                + valuearg2 + "\n"
                + valuearg3)
                .setNegativeButton("Ok", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        Toast.makeText(MainActivity.this, "test toast", Toast.LENGTH_LONG).show();
                    }
                });
        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                String arg1value = arg1.getText().toString();
                valuearg1 = Integer.parseInt(arg1value);
                String arg2value = arg2.getText().toString();
                valuearg2 = Integer.parseInt(arg2value);
                String arg1value3 = arg3.getText().toString();
                valuearg3 = Float.parseFloat(arg1value3);

                builder1.setMessage("Values are :" + valuearg1 + "\n"
                        + valuearg2 + "\n"
                        + valuearg3)
                        .setNegativeButton("Ok", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialogInterface, int i) {
                                Toast.makeText(MainActivity.this, "test toast", Toast.LENGTH_LONG).show();
                            }
                        });

                builder1.show();
            }
        });
    }
    catch (Exception e)
    {
        Toast.makeText(this, "bug detected", Toast.LENGTH_LONG).show();
    }
}

无法从Edittext获取价值

4 个答案: